JP5081666B2 - Fine pattern molding die and manufacturing method thereof - Google Patents

Description

  The present invention relates to a mold for forming a molded article having a fine pattern and a method for manufacturing the same, and particularly, a nano-unit fine pattern can be formed on a transfer surface of a mold with high accuracy. .

  As a known example of the prior art related to the present invention, that is, a technique for processing a transfer surface of a molding die with high accuracy, Japanese Patent Application Laid-Open No. 2005-272254 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2004-268331 ( Some are described in Patent Document 2).

[Prior art 1]
What is described in the above Patent Document 1 (Japanese Patent Laid-Open No. 2005-272254) relates to an optical element molding die for molding a high-precision glass optical element such as a lens and a method for manufacturing the same. This is a manufacturing method of an optical element molding die that is excellent in productivity and can obtain a highly accurate molding surface shape at low cost. The main component is iron made into a powder having an average particle diameter of 2 μm by a high-pressure water atomization method. The powder 2 of the metallic glass (glass transition temperature (Tg) of 540 ° C. and crystallization start temperature (Tx) of 590 ° C.) is sintered as a body 3 to be sintered by a discharge plasma sintering method at a temperature lower than Tx. And obtaining a molding surface. A discharge plasma sintering apparatus 6 for performing this discharge plasma sintering method includes a vacuum chamber 8 in which a sintering unit 7 is disposed, and a sintering unit 7 provided above and below the vacuum chamber 8. An upper punch electrode 10 and a lower punch electrode 11 disposed between them, and a power source 12 for applying pulse power to the sintering unit 7 through these electrodes (FIG. 16), and a high glass transition temperature. Even a metallic glass having (Tg) can form a large bulk.
FIG. 16 is a diversion of FIG. 1 of Patent Document 1, and the reference numerals are the same as those in FIG.

[Prior art 2]
In addition, what is described in Patent Document 2 (Japanese Patent Application Laid-Open No. 2004-268331) is an optical having a microstructure of a complicated shape such as a CGH (Computer Generated Hologram) 16 or a cone shape on a curved surface such as a lens surface. A mold manufacturing method for molding an element, in which a mold 1 includes a mold base material 2, a processing layer 3, and an etching layer 4, and is roughly processed into a shape corresponding to a lens surface. A processing layer 3 is laminated on the base material 2, the processing layer 3 is processed with high accuracy into a shape corresponding to the lens surface, and an etching layer 4 is formed on the processing layer 3. 4 has a fine structure formed by etching (FIG. 17). In this prior art, the surface accuracy of the mold can be ensured by machining, and the shape accuracy of the fine structure can be obtained by etching the etching layer 4.
Note that FIG. 17 is a diversion of FIG. 1 of Patent Document 2, and the reference numerals are the same as those in FIG.

[Prior art]
Moreover, although it is not a well-known example, there exists a thing of Japanese Patent Application No. 2006-183320 as a prior art. This prior art forms a molded product having a fine pattern with a large number of fine grooves on a surface composed of an inclined surface, a curved surface, a free curved surface, etc. by forming a fine pattern having a structure that can be easily released during molding. In a molded product formed by transfer from a mold and having a fine pattern on the surface where the mold releasing direction by mold opening at the time of molding and the normal direction of the surface form an angle, the slope of the surface Alternatively, the micro groove has a group of micro grooves in which a large number of micro grooves extending along the direction in which the curved surface inclines is arranged, and the micro grooves are formed on the entire surface so that the interval between adjacent micro grooves is equal to or less than a predetermined interval. By arranging, since the fine groove exists in the direction inclined from the part where the surface is not inclined with respect to the releasing direction of the mold opening at the time of molding, the opening of the fine groove has the releasing direction. Face It becomes bets, in which the release can be facilitated.

[Problems of the prior art]
Incidentally, in recent years, an antireflection function, a diffraction function, or a polarization function has been added by forming a fine pattern on the optical surface of an optical element. Regardless of optical elements, in recent years, fine patterns have been formed on surfaces for wettability control, friction control, and the like. As a processing method, there is a semiconductor process such as machining or photolithography or etching. However, for mass production, a method of forming a fine pattern on a mold and then transferring it to a resin or glass is preferable.

[Regarding Prior Art 1]
In Patent Document 1 (Japanese Patent Laid-Open No. 2005-272254), metallic glass powder is sintered by a discharge plasma sintering method (SPS method) to obtain a mold, but metallic glass is a multi-component material. Therefore, it is very difficult to form a fine pattern by etching.

[Conventional technology 2]
In the prior art of Patent Document 2 (Japanese Patent Laid-Open No. 2004-268331), a die base material made of a stainless steel material is machined, and nickel is laminated on the die base material by electroforming. The surface layer for forming a fine pattern is formed by sputtering, vacuum vapor deposition, CVD (Chemical Vapor), and finished by ultra-precise cutting or polishing so that it has a predetermined shape corresponding to the shape of the molding object and has a predetermined accuracy. After forming a film by a method such as Deposition, a resist is applied and exposure is performed with an electron beam or the like. And the metal mold | die in which the fine pattern was formed can be obtained by performing dry etching using the formed resist pattern. However, in such a method, it is necessary to machine the mold base material and the nickel layer, and the mold manufacturing process becomes complicated. In addition, it is difficult to make the surface layer for forming a fine pattern formed by sputtering, vacuum deposition, CVD, etc. into a thick film, and the film thickness is at most several μm, and the size of the fine pattern Is limited by its film thickness.
JP 2005-272254 A JP 2004-268331 A

  Therefore, the present invention avoids complication of the manufacturing process for a mold manufacturing method for forming a molded product having a fine pattern, and the fine pattern size is not limited, and the fine pattern is formed on the surface of the desired shape. An object of the present invention is to devise a mold processing method so that it can be formed with high accuracy by an easy manufacturing process.

  The means for solving the above-mentioned problems is to use a mold for a discharge plasma sintering method (hereinafter referred to as “SPS method”) processed so as to obtain a mold shape corresponding to the shape of the object to be molded and its accuracy. Then, at least the molding transfer surface of the mold is prepared by sintering fine nanoparticles of a material capable of reactive ion etching, and a mask pattern is formed on the surface by the SPS method. Forming a pattern.

The fine nanoparticles forming the molded transfer surface are any one of Si, Si ₃ N ₄ , SiC, TiN, SiO ₂ , Ta ₂ O ₅ , diamond, and glassy carbon. As the base material for the mold, any one of cemented carbide, SiC, Si ₃ N ₄ , stainless steel, and glassy carbon is selected. The fine mask pattern is preferably formed by cutting with a small tool and a constant processing load.

  In addition, since at least the mold transfer surface of the mold is formed by sintering the fine nanoparticles by the SPS method (discharge plasma sintering method), the sintering is completed in a short time. For this reason, sintering can proceed only at the interface between the particles. That is, since it can suppress that a fine nanoparticle grows large, since it becomes a precise | minute material which consists of a fine particle, it is possible to form a highly accurate fine pattern. In the SPS method, since the shape of the molding transfer surface can be transferred from the mold shape of the SPS method, it is possible to omit at least the roughing process of the molding transfer surface. Furthermore, in the SPS method, the thickness of the layer that forms the molded transfer surface can be increased according to the size of the fine pattern, so that there is no restriction on the size and shape of the fine pattern. According to the SPS method, since the sintering is completed in a short time and the mold shape can be transferred, it is easy to produce many molds for molding a molded product having a fine pattern.

  Furthermore, since the fine pattern is formed by reactive ion etching after the fine mask pattern is formed on the molded transfer surface, the fine pattern can be easily formed in a short time in combination with the mask (resist). In addition, a fine pattern can be formed not only in a minute region but also in a large area.

In addition, since the fine nanoparticles are any one of Si, Si ₃ N ₄ , SiC, TiN, SiO ₂ , Ta ₂ O ₅ , diamond, and glassy carbon, processing for forming a fine pattern is performed by a reactive ion etching method. It is possible to obtain a mold in which a fine pattern is easily formed. Furthermore, a mold excellent in releasability and durability can be obtained.

Next, since any of cemented carbide, SiC, Si ₃ N ₄ , stainless steel, and glassy carbon is used as the base material of the mold, high strength and high thermal conductivity desired for the mold can be obtained.

  Furthermore, since a fine mask pattern is formed by performing cutting with a constant processing load with a minute tool, processing with a constant depth is possible. Therefore, only unnecessary portions of the mask can be processed, and a fine pattern with a certain depth is formed by reactive ion etching. Various patterns can be formed by the movement of the machine (parallel mechanism, multi-axis machining device or stage).

[Invention of Claim 1]
According to the first aspect of the present invention, at least the molding transfer surface of the mold is formed by sintering the fine nanoparticles by the discharge plasma sintering method (SPS method), so that the sintering is completed in a short time. For this reason, sintering can proceed only at the interface between the particles. That is, since it can suppress that a fine nanoparticle grows large, since it becomes a precise | minute material which consists of a fine particle, it is possible to form a highly accurate fine pattern. Further, in the SPS method, since the shape of the molding transfer surface can be transferred from the SPS mold shape, at least the roughing process of the molding transfer surface can be omitted. Furthermore, in the SPS method, the thickness of the layer that forms the molded transfer surface can be increased according to the size of the fine pattern, so that there is no restriction on the size and shape of the fine pattern. According to the SPS method, the sintering can be completed in a short time and the mold shape can be transferred. Therefore, it is easy to produce a large number of molds for molding a molded product having a fine pattern.

  Furthermore, since the fine pattern is formed by reactive ion etching after the fine mask pattern is formed on the molded transfer surface, the fine pattern can be easily formed in a short time in combination with the mask (resist). In addition, a fine pattern can be formed not only in a minute region but also in a large area.

[Invention of Claim 2]
In the invention of claim 2, since the fine nanoparticles are any one of Si, Si ₃ N ₄ , SiC, TiN, SiO ₂ , Ta ₂ O ₅ , diamond, and glassy carbon, a fine pattern is formed by a reactive ion etching method. Therefore, a mold having a fine pattern can be easily obtained.

[Invention of claim 3]
According to the invention of claim 3, since any of cemented carbide, SiC, Si ₃ N ₄ , stainless steel, and glassy carbon is used as the base material of the mold, high strength and high thermal conductivity desired for the mold can be obtained. It is done.

[Invention of claim 4]
In the invention of claim 4, since a fine mask pattern is formed by performing cutting with a constant processing load with a minute tool, processing of a constant depth is possible, and only unnecessary portions of the mask are processed. Therefore, it becomes possible to form a fine pattern with a certain depth by reactive ion etching. Further, various patterns can be formed by the movement of the machine (parallel mechanism, multi-axis machining apparatus or stage).

[Invention of Claim 5]
In the invention of claim 5, since at least the molding transfer surface of the mold is Si, Si ₃ N ₄ , SiC, TiN, SiO ₂ , Ta ₂ O ₅ , diamond, or glassy carbon, the mold release property and durability are improved. An excellent mold can be obtained. In addition, since any of cemented carbide, SiC, Si ₃ N ₄ , stainless steel, and glassy carbon is used as the base material of the mold, high strength and high thermal conductivity desired for the mold can be obtained. Therefore, a molded product having a fine pattern can be stably obtained with high accuracy.

In the present invention, in the mold for molding the surface of the molded article, at least the mold transfer surface of the mold is Si, Si ₃ N ₄ , SiC, TiN, SiO ₂ , Ta ₂ O ₅ , diamond, glassy carbon. It is characterized by being formed by sintering any one of the above fine nanoparticles by an SPS (discharge plasma sintering) method.
Here, Si, Si ₃ N ₄ , SiC, TiN, SiO ₂ , Ta ₂ O ₅ , diamond, and glassy carbon are materials that can be processed for forming a fine pattern by a reactive ion etching method. In the principle of reactive ion etching, the etching gas is turned into plasma in the reaction chamber, a high frequency is applied to the cathode that fixes the sample, a potential is generated between the sample and the plasma, and ion species and radicals in the plasma are accelerated to the sample. At this time, the physical sputtering by ions and the chemical reaction with the etching gas act simultaneously, so that the processing is performed.

  A metal mold is formed by sintering fine nanoparticles having a diameter of 1 μm or less of the above material by the SPS method. According to the principle of the SPS method, the gap between the green compact particles (Note: The gap formed between the powder particles inserted in the mold used for the SPS method and pressed with the powder before sintering) By applying a large pulsed current at a low voltage, the high energy of the discharge plasma generated instantaneously by the spark discharge phenomenon can be effectively applied to thermal diffusion and electric field diffusion. Sintering can be completed in a short time of about 5 to 20 minutes including the temperature rising and holding time in a temperature range lower by 200 to 500 ° C. than the conventional method in a high temperature range from low temperature to 2000 ° C. or higher. Here, in the SPS method, since the sintering is completed in a short time, the sintering can be allowed to proceed only at the interface between the particles, thereby suppressing the large growth of the fine nanoparticles. it can. Further, if the fine nanoparticles are amorphous, it can be sintered in a state where the amorphous state is substantially maintained. The SPS method is a discharge plasma sintering method, which is also called an electric current sintering method or a plasma activated sintering method. In the present invention, if the sintering method is based on the above principle, the sintering method is used. Can be adopted.

  When a fine pattern is formed by reactive ion etching, the etching rate differs for each crystal grain, so that a step is generated due to the presence of the crystal grain. This phenomenon may reduce the precision of the shape of the fine pattern. For example, in the case of fine nanoparticles having a diameter of 1 μm or less, the crystal grain size is naturally a nanosize of 1 μm or less. When such fine nanoparticles are sintered by the SPS method, the growth of the particles is suppressed. It becomes a sintered body formed of crystal grains. When this sintered body is processed by reactive ion etching, the level difference due to the presence of crystal grains is suppressed to nano-size, and a highly accurate fine pattern can be formed. The size of the crystal grains is sufficient if it is about 1/10 or less of the size of the fine pattern. Here, the size of the fine pattern means the size of the smaller one of the width and the depth. Further, if the fine nanoparticles are not crystalline but amorphous, there is no processing step due to the difference in etching rate for each crystal grain, which is advantageous for forming a fine pattern.

In such a mold, the mold is obtained by sintering only fine nanoparticles of any one of Si, Si ₃ N ₄ , SiC, TiN, SiO ₂ , Ta ₂ O ₅ , diamond, and glassy carbon by the SPS method. However, it is preferable to form a molded transfer surface with the above-mentioned nanoparticles and use any one of cemented carbide, SiC, Si ₃ N ₄ , stainless steel, and glassy carbon as the base material. This is because high strength and high thermal conductivity desired as a mold can be obtained. The material that forms the base material is put into the SPS process as a bulk material (note: the object as a lump. Sintering the nanoparticles and bonding them together to form a mold, or the material that forms the base material as particles (powder) and putting it into the SPS process, together with the fine nanoparticles that form the molding surface It may be integrally sintered. Or you may join the sintered compact and the base material which formed the shaping | molding transcription | transfer surface by sintering a fine nanoparticle by SPS method. Furthermore, it is preferable that the interface between the molded transfer surface forming portion and the base material has a so-called gradient composition in which the composition of each material gradually changes.

[Example 1]
Prepare a die and punch made of cemented carbide to make a mold for SPS. As shown in FIG. 1 (cross-sectional view), the die 11 and the punches 12a and 12b are processed in order to form a mold having a desired shape. The upper punch 12a has a molding surface in a shape that matches the lens shape. A material obtained by processing the SiC bulk material 13 into a desired shape is disposed below the space formed by the die 11, the punch 12a, and the punch 12b. Next, a mixture of diamond fine nanoparticles 14 having a diameter of about 6 nm and SiC particles in a volume ratio of 1: 4 is placed on a SiC base material (bulk material) 13 and pressed by punches 12a and 12b. After the upper punch 12a is pulled out, a mixture having a volume ratio of 2: 3 is further arranged on the punch 12a, and this is pressed by the punches 12a and 12b. In this way, those mixed at a volume ratio of 3: 2, 4: 1 are sequentially arranged, and finally diamond fine nanoparticles are arranged and pressed with a punch.

  Next, evacuation is performed in the vacuum chamber of the SPS apparatus in which the portion shown in FIG. 1 is arranged, and then the upper and lower punches 12a and 12b are energized to apply a pulse voltage. The sintering temperature is 1000 ° C. for 2 minutes at the temperature of the die 11, and the pressure is 30 MPa. Then, after cooling for 30 minutes, the sintered body was taken out from the mold for SPS. The molding transfer surface of the produced sintered body was coated with Al as a mask by ion plating. This Al was subjected to AFM processing (fine processing applying the principle of a scanning probe microscope) to form a fine mask pattern. Diamond is exposed in the AFM processed part.

  Here, FIG. 2 shows the principle of AFM processing. When the probe 15 traces the surface of the substance (workpiece), the piezo 17 expands and contracts so that the amount of warpage of the cantilever 16 is maintained constant, that is, the detection position of the laser beam at the photodiode is constant. Feedback control in which the Z axis moves up and down is performed. Maintaining the amount of warping of the cantilever 16 constant means maintaining a constant force acting between the probe 15 and the substance (workpiece), and the force at the time of measurement is minute, so it is called an interatomic force. . By setting the amount of warp, it is possible to generate a load larger than the atomic force, and it is possible to process a substance (workpiece). Since the generated load can be kept constant, groove processing with a constant depth is possible. Even if the object to be processed is a curved surface, it is possible in principle to perform groove processing with a constant depth by following the curved surface. Since the stroke of feedback control by the piezo 17 is about several μm, a device capable of three-dimensional scanning with a head portion as shown in FIG. 2 is required for processing a curved surface.

  Therefore, the processing head of the mechanism as shown in FIG. 2 was mounted on the parallel link mechanism as shown in FIG. 3 to process the mask material on the molded transfer surface. This is a device that can perform machining at any angle by the parallel link mechanism 19. By moving the machining head 18 by the parallel link mechanism 19, a tool path is generated on the molding surface of the mold, and the piezo of the machining head portion is generated. It is possible to process the fine mask pattern on the mold forming surface by controlling so that the processing load is constant. In the first embodiment, the parallel link mechanism 32 is employed, but a multi-axis machining apparatus or stage composed of five or six axes may be employed.

Next, the fine pattern portion where the molding transfer surface was exposed was etched by a reactive ion etching method. The gas used for the etching was CF ₄ + O ₂ and etching was performed for 10 minutes. Here, in the etching process, the etching conditions are selected so that the Al mask is completely removed at the end of the etching. However, if the Al mask remains at the end of the etching, a separate step of removing only Al may be provided. The mold produced as described above is shown in FIG. And when the plastic lens was shape | molded using the metal mold | die shown in this FIG. 4, the lens shape and the fine pattern shape were able to be transferred with high precision. FIG. 5 shows an arrangement of fine patterns on the surface of the molded lens. The cross-sectional shape of the fine pattern of this example is a V-groove shape having an opening width of 180 nm and a depth of 250 nm, and has an antireflection function for light in the visible light range. Even after continuous molding, the mold releasability was excellent, and no plastic adhered to the fine pattern of the mold. Furthermore, since the diamond is very hard, there is no defect in the fine pattern of the mold.

  In the first embodiment, the shape of the interface between the bulk material serving as the base material and the molding transfer surface is assumed to be a flat surface, but as shown in FIGS. 6 and 7, the interface between the base material and the molding transfer surface is used. The shape may be substantially the same as the shape of the molding transfer surface.

[Example 2]
In Example 2 shown in FIGS. 6 and 7, a graphite die and punch are prepared, and these are used as SPS molds. As shown in FIG. 8 (sectional view), the die 21 and the punches 22a and 22b are processed in order to form a mold having a desired shape. The upper punch 22a is formed in a shape that matches the lens shape. Cemented carbide (WC) particles are placed below the space formed by the die 21 and the punches 22a and 22b, and pressed by the punches 22a and 22b. Next, after the upper punch 22a is pulled out, a mixture of TiN fine nanoparticles 24 having a diameter of about 60 nm and cemented carbide particles in a volume ratio of 1: 4 is formed on the cemented carbide as the base material 23. And press with a punch. Further, a mixture having a volume ratio of 2: 3 is placed thereon and pressed with a punch. In this manner, those mixed at a volume ratio of 3: 2, 4: 1 are sequentially arranged, and finally TiN fine nanoparticles are arranged.

  Next, the vacuum chamber of the SPS apparatus in which the portion shown in FIG. 8 is evacuated is evacuated, and then the upper and lower punches are energized to apply a pulse voltage. The sintering temperature is 1600 ° C. for 2 minutes at the die temperature, and the pressure is 30 MPa. Then, after cooling for 50 minutes, the sintered body was taken out from the mold for SPS. The molding transfer surface of the mold thus sintered is finished as necessary. In this example, the finishing process was performed by grinding using a diamond grindstone. Next, a resist is applied to the molding transfer surface by a spray method, and exposure is performed by a two-beam interference exposure method so as to correspond to a desired fine pattern. Thereafter, by performing development, the molded transfer surface is exposed at the portion where the resist is removed.

Next, the exposed fine pattern portion of the molding transfer surface is etched by reactive ion etching. The gas used for etching was CF ₄ + O ₂ + H ₂ + NH ₃ and etching was performed for 30 minutes. The mold produced as described above is shown in FIG. When a plastic lens was molded using the mold shown in FIG. 9, the lens shape and fine pattern shape could be transferred with high accuracy. Even after continuous molding, the mold releasability was excellent, and no plastic adhered to the fine pattern of the mold.

  FIG. 12 shows an arrangement of fine patterns on the surface of the molded lens. This is an atypical lens in which U-shaped grooves having a pitch of 190 nm and a depth of 300 nm are formed. In Example 2, the shape of the interface between the base material and the molding transfer surface is approximately the same as the shape of the molding transfer surface. However, as shown in FIGS. 10 and 11, the interface has the same shape as the shape of the molding transfer surface. Not only that, but a flat mold can be used. In this case, the cemented carbide particles are arranged below the space formed by the die and the punch as the base material, the surface shape for pressing the particles is pressed with a flat punch, and the sintering is performed by the SPS method. Therefore, a punch formed in a shape matching the lens shape is used.

Example 3
In Example 3, a die and a punch made of cemented carbide are prepared and used as a die for SPS. As shown in FIG. 13 (cross-sectional view), the die 31 and the punches 32a and 32b are processed in order to form a mold having a desired shape. The upper punch 32a is formed in a shape that matches the lens shape. Glassy carbon fine nanoparticles 34 having a diameter of about 100 nm are arranged in a space formed by the die 31 and the punches 32a and 32b, and are pressed by the punches 32a and 32b.

  Next, evacuation is performed in the vacuum chamber of the SPS apparatus in which the portion shown in FIG. 13 is arranged, and then the upper and lower punches 32a and 32b are energized to apply a pulse voltage. The sintering temperature is 800 ° C. for 1 minute at the temperature of the die 31 and the pressure is 40 MPa. Then, after cooling for 30 minutes, the sintered body was taken out from the mold for SPS. The molding transfer surface of the mold thus sintered is finished as necessary. In Example 3, the finishing process was performed by grinding using a diamond grindstone. The molding transfer surface of the produced sintered body was coated with Al as a mask by ion plating. AFM processing was performed on this Al to form a fine mask pattern. The glassy carbon is exposed in the AFM processed part.

Next, the exposed fine pattern portion of the molding transfer surface is etched by reactive ion etching. The gas used for etching was O ₂ and etching was performed for 20 minutes. When a glass lens was molded using the mold produced as described above (FIG. 14), the lens shape and fine pattern shape could be transferred with high accuracy. Even after continuous molding, the mold releasability was excellent, and there was no adhesion of glass to the fine pattern of the mold.
FIG. 15 shows an arrangement of fine patterns on the surface of the molded lens. This is a sub-wavelength sized fine pattern formed on a diffractive surface having a step of about 3 μm. The molding transfer surface of the mold has a sufficient thickness even for a pattern of several μm.

Example 4
In Example 4, a graphite die and punch are prepared and used as a mold for SPS. As shown in FIG. 8 (sectional view), a die and a punch are processed in order to form a mold having a desired shape. The upper punch is formed in a shape that matches the lens shape. Stainless steel particles are placed below the space formed by the die and punch and pressed with a punch. Next, after the upper punch is pulled out, a mixture of Si nanoparticles having a diameter of about 150 nm and stainless steel particles mixed in a volume ratio of 1: 5 is placed on the stainless steel and pressed with the punch. Further, a mixture having a volume ratio of 2: 4 is placed thereon and pressed with a punch. In this way, those mixed at a volume ratio of 3: 3, 4: 2, 5: 1 are sequentially arranged, and finally Si fine nanoparticles are arranged and pressed with a punch.

Next, evacuation of the vacuum chamber of the SPS apparatus in which the portion shown in FIG. 8 is arranged is performed, and then a pulse voltage is applied by energizing the upper and lower punches. The sintering temperature is 800 ° C. for 2 minutes at the die temperature, and the pressure is 40 MPa. Next, a resist is applied to the molding transfer surface by spin coating, and exposure is performed by electron beam exposure so as to correspond to a desired fine pattern. Thereafter, by performing development, the molded transfer surface is exposed at the portion where the resist is removed.
Next, the exposed fine pattern portion of the molding transfer surface is etched by reactive ion etching. The gas used for etching was SF ₆ (Note: sulfur hexafluoride), and etching was performed for 15 minutes. When a plastic lens was molded using the mold produced as described above (FIG. 9), the lens shape and fine pattern shape could be transferred with high accuracy. Even after continuous molding, no plastic adhered to the fine pattern of the mold.

Similarly, 120 nm fine nanoparticles of Si ₃ N ₄ are placed on the molding transfer surface by the SPS method, a sintered body is created at a sintering temperature of 1800 ° C., held for 2 minutes, and a pressure of 50 MPa, and reactive ion etching is performed. Thus, a fine pattern was formed to produce a mold. In addition, fine nanoparticles of 100 nm of SiC are arranged on the molding transfer surface by SPS method, a sintered body is created at a sintering temperature of 1700 ° C., held for 3 minutes, and a pressure of 35 MPa, and a fine pattern is formed by reactive ion etching. This was formed to produce a mold. Also, 200 nm fine nanoparticles of SiO ₂ are arranged on the molding transfer surface by SPS method, sintered body is created at sintering temperature 900 ° C., 3 minutes, pressure 20 MPa, and fine pattern is formed by reactive ion etching. To form a mold. Also, 50 nm fine nanoparticles of Ta ₂ O ₅ are arranged on the molding transfer surface by SPS method, and a sintered body is created at a sintering temperature of 1000 ° C. for 1 minute and under a pressure of 40 MPa, and reactive ion etching is performed. A fine pattern was formed to produce a mold. When a plastic material was molded with each mold, the fine pattern could be transferred satisfactorily.

[Summary]
As described above, according to the present invention, it is possible to easily produce a mold in which a fine pattern is formed on a surface having a desired shape.

FIG. 3 is a cross-sectional view of a mold sintering apparatus according to the SPS method of Example 1; Is an explanatory diagram of the principle of AFM processing FIG. 4 is a partially enlarged view of a processing example for processing a fine mask pattern on a molding transfer surface by AFM processing. FIG. 3 is a sectional view of a mold in which a fine pattern is formed in Example 1; The surface view of the lens which formed the fine pattern with the metal mold | die of an Example FIG. 3 is a cross-sectional view of a mold sintering apparatus according to the SPS method of Example 2; FIG. 3 is a cross-sectional view of a mold having a fine pattern formed in Example 2; These are explanatory drawings of mold sintering processing by the sintering apparatus of Example 2 FIG. 3 is a sectional view of a mold on which a fine pattern of Example 2 is formed. These are explanatory drawings of sintering processing of other molds by the sintering apparatus of Example 2 Fig. 4 is a cross-sectional view of another mold in which the fine pattern of Example 2 is formed. FIG. 3 is a surface view of a lens surface in which a fine pattern is formed with the mold of Example 2; FIG. 4 is a cross-sectional view of a mold sintering apparatus according to the SPS method of Example 3; FIG. 3 is a cross-sectional view of a mold by the sintering apparatus of Example 3 FIG. 4 is a surface view of a lens formed with a fine pattern by the mold of Example 3. FIG. 3 is a cross-sectional view of a conventional die sintering apparatus. FIG. 3 is a cross-sectional view of the etching layer 4 according to the prior art 2 in which a fine structure is formed by etching treatment.

Explanation of symbols

11, 21, 31: Die
12a, 12b, 22a, 22b, 32a, 32b: punch
13, 23: Base material (bulk material),
14, 24, 34: Fine nanoparticles

Claims (5)

In a method for producing a mold for molding a molded product having a fine pattern,
Sintering fine nanoparticles by the discharge plasma sintering method to form at least the mold transfer surface of the mold, forming the fine mask pattern on the mold transfer surface, and reactive ion etching on the mold transfer surface The manufacturing method of the metal mold | die characterized by including the process of forming a fine pattern. 2. The mold manufacturing method according to claim 1, wherein the fine nanoparticles are any one of Si, Si ₃ N ₄ , SiC, TiN, SiO ₂ , Ta ₂ O ₅ , diamond, and glassy carbon. Manufacturing method. 3. The method for manufacturing a mold according to claim 1 or 2, wherein any one of cemented carbide, SiC, Si ₃ N ₄ , stainless steel, and glassy carbon is used as a mold base material, and fine nanoparticles are subjected to spark plasma sintering. A mold manufacturing method comprising forming a molding transfer surface of a mold by sintering by a method.   2. The method for manufacturing a mold according to claim 1, wherein after the mask material is applied or coated on the molding transfer surface, a fine mask pattern is formed by performing a cutting process with a constant processing load with a minute tool. Mold manufacturing method.   A mold manufactured by the mold manufacturing method according to claim 1.