JP2013060650A - Method for manufacturing mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent foreign matter from being adhered to a patterned surface of an electroformed article during a peeling process in a method for manufacturing a mold using an electroforming method.SOLUTION: The method for manufacturing a mold 16 includes: forming an electroformed article 14 with a conductive ring 22 fixed to be coaxial with a master 10; peeling the electroformed article 14 from the master 10 in a cleaning solution 31; and cutting off a part that becomes the mold 16 of a predetermined shape from the electroformed article 14. The master 10 and the conductive ring 22 are secured in such a manner that only two close-contact areas 45 of the master 10 and the conductive ring 22 are formed in a region 15 where the master 10 and the conductive ring 22 overlap each other. The two close-contact areas 45 are substantially opposite each other along a center line 10c of the master 10.

Description

  The present invention relates to a method for manufacturing a mold having a fine concavo-convex pattern on the surface, and particularly to a method for manufacturing using an electroforming method.

  In recent years, magnetic transfer methods and nanoimprint methods for efficiently performing two-dimensional or three-dimensional pattern transfer have been developed. Magnetic transfer is a transfer technique performed in the manufacture of magnetic recording media, and is used for transfer in a state in which a magnetic transfer master disk having a fine magnetic pattern on the surface is in close contact with a slave medium (also referred to as a transfer medium). In this technique, a magnetic field is applied to transfer information (for example, servo signals) corresponding to the magnetization pattern to a slave medium. On the other hand, nanoimprint is a transfer technology performed in the manufacture of discrete track media (DTM), bit patterned media (BPM), etc., and a master substrate for nanoimprint having a fine concavo-convex pattern on its surface is a thermoplastic resin or a photocurable resin. It is a technology that presses the pattern onto the resin and transfers the uneven pattern to the resin. According to such a technique, it is possible to collectively transfer a two-dimensional or three-dimensional pattern by pressing the above-described mold (including the master disk and the master carrier) against a transfer medium. It is possible to easily form a nano-level fine pattern at low cost.

  Conventionally, as shown in Patent Document 1, for example, the above mold is manufactured by, for example, an electroforming method. The process includes, for example, an electroforming process in which a master having a concavo-convex pattern having a shape complementary to a concavo-convex pattern to be formed on a mold is fixed to an electroforming jig, and an electroformed product is formed on the surface. And a peeling step of peeling the electroformed product from the master, and a cutting step of cutting the peeled electroformed product into a predetermined shape. When the mold is a master disk for magnetic transfer, a process for forming a magnetic layer is further added if necessary.

JP 2008-226352 A

  However, in the conventional manufacturing method such as Patent Document 1, due to the electroforming liquid remaining in the slight gap of the electroforming jig during the peeling process, the pattern surface of the electroformed product (of the surface of the master) There may be a problem that foreign matter adheres on the surface of the region where the uneven pattern is actually formed.

  The present invention has been made in view of the above problems, and in the manufacture of a mold using an electroforming method, a mold that makes it possible to prevent adhesion of foreign matters on the pattern surface of an electroformed product during the peeling process. The object is to provide a manufacturing method.

In order to solve the above problems, a mold manufacturing method according to the present invention includes:
A disc-shaped master with a fine uneven pattern formed on one surface is placed on the cathode body,
In a state where an annular conductive ring having an inner diameter smaller than the diameter of the master is fixed concentrically to the one surface of the master, an electroformed product is formed on the one surface,
The electroformed product is peeled from the master in the cleaning solution,
A method of manufacturing a mold for cutting a portion to be a mold of a predetermined shape from an electroformed product,
The master and the conductive ring are fixed so that only two contact areas for the master and the conductive ring are formed in the area where the master and the conductive ring overlap each other.
The two close contact regions are opposed to each other substantially along the center line of the master.

  In this specification, the “contact area” means a surface area where the master and the conductive ring are in close contact.

  And in the manufacturing method of the mold which concerns on this invention, it is preferable that each of two contact | adherence area | regions is contained in the angle range of 60 degrees around the center of an original disk.

  Further, in the mold manufacturing method according to the present invention, the master and the conducting ring are fixed to the cathode body by two holding members corresponding to the positions of the two contact areas, each of which is a pressing ring that holds the conducting ring from above. It is preferably performed by a holding ring that is fixed.

  In the mold manufacturing method according to the present invention, the two fixing members are preferably opposed to each other along the center line of the pressing ring.

  In the mold manufacturing method according to the present invention, in the manufacture of a mold using the electroforming method, the master and the conductive ring are formed so that only two contact areas for the master and the conductive ring are formed in the region where the master and the conductive ring overlap each other. The conductive ring is fixed, and the two contact areas are substantially opposed to each other along the center line of the master. Under such a configuration, the electroformed product can be deposited in a slight gap in a region other than the close contact region in the region where the master and the conductive ring overlap each other, and precipitation can be suppressed in the close contact region. As a result, when the electroformed product is peeled from the master in the stripping process, a region where the cleaning liquid is easy to penetrate and a region where it is difficult to penetrate is formed in the gap between the master and the electroformed product, and foreign matter adheres to the pattern surface of the electroformed product It is possible to lead to a penetration route that is difficult to perform. As a result, in the manufacture of a mold using the electroforming method, it is possible to prevent adhesion of foreign matters on the pattern surface of the electroformed product during the peeling process.

It is a cutting part end view showing roughly the process of the manufacturing method of the mold of an embodiment. It is a cutting part end elevation showing roughly composition of an electroforming jig used with a manufacturing method of a mold of an embodiment. It is a cutting part end elevation showing roughly the state of the electroforming jig to which the master was attached. It is a cut part end view showing roughly the composition of an electroforming device. It is a cutting part end elevation showing roughly the state of the electroforming jig in which the electroformed product was formed. It is an enlarged view which shows roughly the mode of the fixing member periphery of the electroforming jig | tool in which the electroformed product was formed. It is a top view which shows roughly the positional relationship of an overlap area | region, an adhesion | attachment area | region, and a fixing member in embodiment. It is a figure which shows the measurement result of the contact pressure of the original disk and conduction | electrical_connection ring in a contact | adherence area | region. It is a cutting part end elevation showing roughly the process of peeling an electroformed product from a master. It is a figure which shows the surface of the original disk after a peeling process. It is a figure which shows roughly the process of cutting out a disk-shaped part from the electroformed product which peeled. It is a cut part end view which shows roughly a mode that electroforming liquid remains in a slight crevice between a master and a conduction ring after an electroforming process. FIG. 5 is a cut end view schematically showing how the remaining electroforming liquid is washed away by the cleaning liquid and enters a slight gap between the master and the electroformed product in the peeling step. It is a figure which shows roughly a mode that the permeation | transmission path | route of a washing | cleaning liquid changes depending on the number of fixing members.

  Hereinafter, although an embodiment of the present invention is described using a drawing, the present invention is not limited to this. In order to facilitate visual recognition, the scale of each component in the drawings is appropriately changed from the actual one.

  FIG. 1 is an end view of a cut portion schematically showing steps of a method for manufacturing a mold according to an embodiment. FIG. 2 is an end view of a cut portion schematically showing a configuration of an electroforming jig used in the mold manufacturing method of the embodiment. FIG. 3 is an end view of the cut portion schematically showing the state of the electroforming jig to which the master is attached. FIG. 4 is a cut end view schematically showing the configuration of the electroforming apparatus. FIG. 5 is a cross-sectional end view schematically showing the state of the electroforming jig on which the electroformed product is formed. FIG. 6 is an enlarged view schematically showing a state around the fixing member of the electroforming jig on which the electroformed product is formed.

  The mold manufacturing method of the embodiment is performed by an electroforming method using an electroforming jig 20 as shown in FIG. 2 and an electroforming apparatus 60 as shown in FIG. Specifically, in the mold manufacturing method of the embodiment, as shown in FIG. 1, a disk-shaped master 10 having a fine uneven pattern formed on one surface S is disposed on the cathode body 21 (see FIGS. 3), an annular conducting ring 22 having an inner diameter smaller than the diameter of the master 10 is fixed to the one surface S of the master 10 so as to be concentric with the one surface S. A method of manufacturing a mold that forms an electroformed product 14 (FIGS. 1b and 5), peels the electroformed product from the master 10 in a cleaning liquid, and cuts a portion that becomes a mold of a predetermined shape from the electroformed product 14, The master 10 and the conductive ring 22 are fixed so that only two contact areas for the master 10 and the conductive ring 22 are formed in the area where the conductive rings 22 overlap each other. It is characterized in that is intended to face each other along the center line of the master 10 in.

(Master)
The master 10 is a mold for forming an electroformed product. On one surface S of the master, a concavo-convex pattern having a shape complementary to the concavo-convex pattern to be formed on the mold is formed. That is, the concavo-convex pattern formed on the master 10 is appropriately designed according to the concavo-convex pattern to be formed on the mold. In the case of manufacturing a mold such as a magnetic transfer master disk or a nanoimprint master carrier, the concavo-convex pattern formed on the master 10 is usually 0.05 to 20 μm in width W and 20 to 20 in depth H. It is 800 nm, and the length (the length in the direction perpendicular to the paper surface of the convex portion in FIG. 1) is 0.05 to 5 μm. The material of the master 10 is silicon, quartz glass, or metal. From the viewpoint of performing the electroforming method, the master 10 needs to have conductivity on at least the one surface S on which the uneven pattern is formed. Therefore, when the material of the master 10 is made of a material other than metal, the conductive layer 12 is formed on the one surface S before electroforming. The conductive layer 12 is made of, for example, the same type of metal material or magnetic material as the material to be electroformed. The master 10 has a disk shape, and its diameter is appropriately designed according to the size of the mold. The diameter of the master 10 is, for example, 200 mm (8 inches). The thickness of the master 10 is not particularly limited, but is, for example, 0.725 mm.

(Electroforming jig)
The electroforming jig 20 is a jig for fixing the master 10 during the electroforming process. As shown in FIG. 2, the electroforming jig 20 includes a cathode body 21, a conduction ring 22, a pressing ring 23, and a fixing bolt 24.

  The cathode body 21 is an installation base to which the master 10 is attached, and is a member that functions as a cathode during the electroforming process. The cathode body 21 includes a groove 21 a for installing the master 10 and a groove 21 b for installing the conduction ring 22. The diameter of the groove 21 a corresponds to the diameter of the master 10, and the diameter of the groove 21 b corresponds to the diameter of the conduction ring 22. The grooves 21a and 21b are formed so that they are concentric when the master 10 and the conductive ring 22 are installed. Further, a through hole 21 c for allowing the fixing bolt 24 to pass is provided in a flange portion surrounding the outer periphery of the cathode body 21. Further, the cathode main body 21 on the side opposite to the side where the groove 21a is provided is provided with a shaft 21d for connection with electrical wiring on the cathode side of the electroforming apparatus. As the material of the cathode main body 21, various metal materials that do not cause deterioration such as rust due to electroforming can be used.

  Although not shown in the drawings, in the embodiment, the cathode body 21 has a disk shape in a top view, and six through holes 21c are equally provided at the positions of regular hexagonal apexes of the flange portion. .

  The conductive ring 22 is a member for pressing the edge of the master 10 while exposing the pattern surface of the master 10 (the surface of the one surface S where the uneven pattern is actually formed). The conducting ring 22 has an annular shape, and the inner diameter (the diameter of the inner circumferential circle) is slightly smaller than the diameter of the master 10. Thus, when the master 10 is installed in the groove 21a of the cathode main body 21 and the conductive ring 22 is installed in the groove 21b of the cathode main body 21, the master 15 and the conductive ring 22 overlap with each other (area 15). Thus, the master 10 is pressed by the conduction ring 22 (FIG. 6). The “overlapping region” is a space region where the master 10 and the conductive ring 22 appear to overlap when the state in which the conductive ring 22 is installed concentrically with the one surface S of the master 10 is viewed from above. Means. As a material for the conductive ring 22, various metal materials that do not cause deterioration such as rust due to electroforming, such as stainless steel and titanium, can be used to ensure electrical connection to the master 10. The outer diameter (the diameter of the outer circumference circle) and the thickness of the conductive ring 22 are appropriately designed according to the overall configuration and size of the electroforming jig 20.

  The holding ring 23 is an annular member for holding the conduction ring 22. The holding ring 23 includes six bolt holes 23 a into which the fixing bolts 24 are fitted so as to correspond to the through holes 21 c, and is fixed to the cathode body 21 by the fixing bolts 24. The inner diameter of the holding ring 23 is designed to be larger than the inner diameter of the conduction ring 22 and smaller than the outer diameter thereof. The pressing ring 23 is provided with a protrusion 23b over the entire circumference. Then, when the pressing ring 23 is fixed to the cathode main body 21, the protrusion 23 b presses the conduction ring 22. The material of the pressing ring 23 is not particularly limited, but for example, a resin material such as polyvinyl chloride can be used.

  The fixing bolt 24 is a fixing member for fixing the pressing ring 23 to the cathode main body 21. The fixing bolt 24 fixes the pressing ring 23 to the cathode body 21 so as to form two contact areas. The number of fixing bolts 24 is not particularly limited as long as the holding ring 23 can be fixed to the cathode body 21 as described above. A simple method of fixing the pressing ring 23 to the cathode main body 21 is a method of fixing with the two fixing members corresponding to the respective positions of the two close contact regions. The size and shape of the fixing bolt 24 are appropriately designed according to the overall configuration and size of the electroforming jig 20. In addition, as the material of the fixing bolt 24, various metal materials that do not cause alteration such as rust due to electroforming can be used.

The fixing member in the present invention is not limited to the bolt type as described above. For example, a member that sandwiches and fixes the cathode main body 21 and the pressing ring 23 from both sides can be used.
When the master 10 is attached to the electroforming jig 20 as described above, the state shown in FIG. 3 is obtained.

(Fixing method of master)
In the present invention, the master 10 and the conductive ring 22 are fixed so that only two contact areas for the master 10 and the conductive ring 22 are formed in the overlapping region. This overlapping region has an annular shape depending on the shapes of the master 10 and the conductive ring 22. The “contact area” means a surface area where the master 10 and the conductive ring 22 are in close contact. Furthermore, “in close contact” means that the master 10 and the conduction ring 22 are in contact with each other with a contact pressure of 0.7 MPa or more. The contact pressure between the master 10 and the conductive ring 22 is a pressure measurement film 25 (product number: for ultra-low pressure, code: LLW, pressure measurement range: 0.5 to between the master 10 and the conductive ring 22. 2.5 MPa). The pressure measurement film 25 develops a red color at the pressurized portion, so that the surface pressure distribution can be visualized and quantified. Therefore, the magnitude of the contact pressure is measured by comparing the color intensity of the colored portion of the pressure measuring film 25 with the attached color sample.

  “Only two close contact regions are formed” means that a contact state where the contact pressure is 0.7 MPa or more is a continuous contact region, and the contact pressure region is less than 0.7 MPa. This means that only two separated contact areas are formed. Here, “only” means that there is no contact region of a size that affects the effect of the present invention in addition to the two contact regions. Therefore, for example, it is allowed that a minute adhesion region exists within a range that does not affect the effect of the present invention.

  In the present invention, the two contact areas are opposed to each other substantially along the center line of the master 10. FIG. 7 is a top view schematically showing the positional relationship between the overlapping region 15, the contact region 45, and the fixing bolt 24 (fixing member). FIG. 7 shows the state in which the master 10 and the conductive ring 22 are arranged concentrically as viewed from the conductive ring 22 side. In FIG. 7, the holding ring 23 is omitted. In FIG. 7, an area surrounded by the outer edge 10 a of the master 10 and the inner edge 22 a of the conduction ring 22 is an overlapping area 15.

  As shown in FIG. 7, the two close contact areas 45 are “opposing each other along the center line of the master”, and the centers of the two close contact areas 45 face each other across the center 10 b of the master 10. It is located on the same center line 10c passing through its center 10b. The “center of the contact area” is a position that equally divides the contact area in the circumferential direction, that is, an angular range around the center 10b of the master 10 and divides the angle range θ occupied by the contact area into two equal parts. Means position. In addition, “substantially” means a first center line passing through the center of one contact region 45 and the center 10b of the master 10 and a second center passing through the center of the other contact region 45 and the center 10b of the master 10. The case where the angle formed with the center line is deviated from 0 ° within a range that does not affect the effect of the present invention is also included in the scope of the present invention.

  In the present invention, the two contact areas 45 are preferably opposed to each other along the center line of the master 10. Each of the two close contact regions 45 is preferably included in an angular range of 60 ° around the center 10b of the master 10, that is, the angular range θ in FIG. 7 is preferably 60 ° or less. However, the angle range θ for each of the two close contact regions does not necessarily match. The angle range θ is adjusted, for example, by adjusting the force with which the fixing member of the pressing ring 23 is fixed. Such two close contact regions 45 are, for example, two locations facing the pressing ring 23 along the center line of the pressing ring 23 (positions 44a in FIG. 7). This is realized by fixing the cathode body 21 with the two fixing bolts 24). In this case, if the center of one contact region 45 is a 0 ° position with respect to the center 10b of the master 10, the center of the other contact region 45 is a 180 ° position. Actually, as a result of fixing the pressing ring 23 to the cathode main body 21 with two fixing bolts 24 at two locations facing each other along the center line of the pressing ring 23, as shown in FIG. The color developed in an angle range of 60 °.

(Electroforming process)
The formation of the electroformed product 14 on the one surface S is actually performed using the electroforming apparatus 60. Specifically, it is as follows.

  The electroforming apparatus 60 is filled with a storage tank 64 for storing the electrolytic solution 62, a drain tank 66 for receiving the electrolytic solution 62 a overflowed from the storage tank 64, and nickel pellets 68 serving as an anode, and overflowed from the storage tank 64. The anode chamber 70 receives the electrolytic solution 62b, and the electroforming jig 72 to which the master 10 is attached.

  An electrolytic solution 62 is supplied to the storage tank 64 from an electrolytic solution supply pipe 74. Further, the electrolytic solution 62 a overflowing from the storage tank 64 to the drain tank 66 is recovered from the drain tank drain pipe 76. The electrolytic solution 62b overflowing from the storage tank 64 to the anode chamber 70 is recovered from the anode chamber drain pipe 78.

  The storage tank 64 and the anode chamber 70 are separated by a partition plate 80. An electrode shielding plate 82 is fixed to the surface of the partition plate 80 on the storage tank 64 side so as to face the electroforming jig 72. The electrode shielding plate 82 is formed so as to cover a predetermined portion of the electrode so that the film thickness of the electroformed electroformed product is uniform in the plane.

  In the electroforming apparatus 60 having the above configuration, the negative electrode is connected to the electroforming jig 72 to which the master 10 is attached, and the positive electrode of the anode chamber 70 is connected. Then, the electroformed product 14 is electroformed by energizing the electroformed jig 72 while obtaining a rotation difference around the central axis 72a of the shaft of the electroformed jig 72.

(Peeling process)
First, the master 10 on which the electroformed product 14 is formed is taken out from the electroforming jig 72 while sufficiently washing the electroforming jig 72 after the electroforming process. At this time, as a result of forming the electroformed product 14, the master 10, the conductive ring 22, and the electroformed product 14 are integrally configured. Next, a cleaning container 30 in which a pure cleaning liquid 31 is stored and a support member 32 is placed is prepared, and the integrally configured object is placed on the support member 32 (FIG. 9a). For example, as shown in FIG. 9, the support member 32 has a cylindrical structure with an opening that can support the integrally configured object at the outer peripheral circle portion of the conducting ring 22. When the integrated structure is installed on the support member 32, a gap is generated between the master 10 and the conductive ring 22, and the cleaning liquid 31 flows from the gap toward the center of the master 10 and the electroformed product 14 (see FIG. 9B). It gradually penetrates in the direction of the reference numeral 31a (FIG. 9b). After that, when the cleaning liquid 31 penetrates all the interface regions between the master 10 and the electroformed product 14, the master 10 falls by its own weight (FIG. 9c).

  When the master 10 with the conductive layer 12 is used, as a result of this peeling step, the conductive layer 12 may be peeled along with the electroformed product 14 (FIG. 1c). Therefore, “peeling the electroformed product from the master” means not only peeling the electroformed product 14 from the master 10 with the conductive layer 12 but also peeling the electroformed product 14 with the conductive layer 12 from the master 10 as described above. It also means to do.

  In the present invention, in the electroforming process, the adhesion region 45 is not formed in the overlapping region 15, and as a result, a precipitate is generated in a portion where a gap is generated between the master 10 and the conduction ring 22. FIG. 10 is a view showing the surface of the master 10 from which the electroformed product 14 has been peeled, on which the electroformed product 14 has been formed. Reference numeral 46 in FIG. 10 indicates a region (precipitation region) where a precipitate is deposited on a part of the surface of the portion of the master 10 that is included in the overlapping region.

(Cut off process)
In the cutting step, a portion having a predetermined shape is cut out from the electroformed product 14 after the peeling step in accordance with the intended use (FIG. 11b). And this cut-out part becomes a mold (FIG. 11c). FIG. 11 schematically shows a process of cutting a disk-shaped portion from the peeled electroformed product 14. The cutting method is not particularly limited, and a punching method or a wet etching method can be used.

(Operational effect of the present invention)
Hereinafter, the function and effect of the present invention will be described.

  Conventionally, in a mold manufacturing method using an electroforming method, foreign matters are formed on the pattern surface of the electroformed product 14 due to the electroforming liquid remaining in a slight gap of the electroforming jig 20 during the peeling process. There was a case where the problem of adhesion occurred. Although the mechanism that causes such a problem is not clear, the following mechanism is presumed.

  Specifically, as shown in FIG. 12, there is a possibility that the electroforming liquid 62 containing minute precipitates remains in the slight gap 40 between the master 10 and the conductive ring 22 after the electroforming process. It is done. Such an electroforming liquid 41 is considered to contain fine precipitates from the relationship of the lines of electric force. In addition, since such an electroforming liquid 41 remains in a slight gap 40 between the master 10 and the conductive ring 22, it is considered that it cannot be removed by cleaning performed before the master 10 and the electroformed product 14 are peeled off. Then, the above factors overlap, and the cleaning liquid 31 permeates from the gap 40 toward the center of the master 10 and the electroformed product 14 (the direction of reference numeral 31a in FIG. 13) during the peeling process. It is considered that the liquid 41 penetrates the gap 42 between the master 10 and the electroformed product 14 with the penetration (FIG. 13). Further, such a phenomenon is considered to occur over the entire overlap area. As a result, the electroforming liquid 41 that has permeated from the outer periphery of the master 10 and the electroformed product 14 is collected at the center of the master 10 and the electroformed product 14, and the minute precipitates contained in the electroformed liquid 41 are the pattern surface of the electroformed product 14. It is thought that it adhered to the top.

  In view of this, the present inventor considers that it is difficult to completely remove the electroforming liquid 41 remaining by washing, and even if the electroforming liquid 41 remains, foreign substances are not formed on the pattern surface of the electroformed product 14. A method for preventing adhesion was examined. As a result, the present inventors have reached the present invention.

  Specifically, the present inventor has found that foreign substances can be prevented from adhering to the pattern surface of the electroformed product 14 by restricting the entrance when the cleaning liquid penetrates into the gap 42.

  FIG. 14 is a diagram schematically illustrating how the permeation path of the cleaning liquid 31 changes depending on the number of fixing members. In FIG. 14, columns a, b, and c represent cases where the number of fixing members is 2, 4, and 6, respectively. That is, the column c corresponds to a general case that has been conventionally performed.

  The first column shows the case where the master 10 and the conductive ring 22 are arranged concentrically from the conductive ring 22 side in each case after the electroforming process. The position of the reference numeral 44a represents the position fixed by the fixing member. The holding ring is not shown. In the a-1 column and the b-1 column, precipitation regions 46 generated according to the number of fixing members are shown. The reason why the precipitation region 46 in the b-1 column is shorter than the precipitation region 46 in the a-1 column is that the pressing ring is fixed by more fixing members in the case of the b-1 column than in the case of the a-1 column. This is because the contact area becomes wider. For the same reason, in the case of the c-1 column, the adhesion region is formed over the entire circumference of the overlapping region, and no precipitate is deposited in the gap between the master 10 and the conductive ring 22, so the precipitation region 46 is not shown.

  Columns 2 to 5 represent changes over time in the degree of penetration of the cleaning liquid 31b penetrating between the master 10 and the conductive ring 22 or the electroformed product 14 in the peeling step. Columns 2 to 5 show a case where a quartz glass substrate is used as the master 10 and viewed from the side opposite to the column 1, that is, from the master 10 side. By using the quartz glass substrate, it is possible to directly observe the degree of penetration of the cleaning liquid 31b.

  In the case of column a, it can be seen that the cleaning liquid 31b permeates from the outer peripheral side of the overlapping region over the entire periphery (column 2). Then, after that, the cleaning liquid 31b penetrates between the two precipitation regions 46 (column 3), and the vicinity of the center of the master 10 is first filled with the cleaning liquid, and then the position deviated from the vicinity of the center is filled with the cleaning liquid. I can see the situation. This is because the electroforming liquid does not penetrate and the precipitate does not precipitate in the overlapping region of the angle range where the close contact region is formed (for example, the angle range viewed from the center of the master 10). This is because the cleaning liquid 31b easily penetrates into the area. In other words, the deposition region 46 limits the entrance when the cleaning liquid 31b penetrates into the gap 42.

  The column a shows the case where the last position to be filled is on the right side, but in fact, the case where the position is on the left side and the both sides are filled almost simultaneously may occur. This depends on a delicate mechanical balance when the master 10 and the electroformed product 14 are peeled off, and is not an essential problem of the present invention. The important point is that the position finally filled with the cleaning liquid 31b deviates from the vicinity of the center of the master 10.

  On the other hand, in the case of columns b and c, the phenomenon that the position finally filled with the cleaning liquid 31b deviates from the vicinity of the center of the master 10 does not occur. In the case of column b, the above phenomenon does not occur because the precipitation region 46 exists, but the entrance restriction is insufficient to cause the above phenomenon.

  In other words, by forming the precipitation region in the overlapping region, the entrance when the cleaning liquid penetrates into the gap 42 is limited, and a permeation path that can prevent adhesion of foreign matter on the pattern surface of the electroformed product 14 is generated. I can say that. In the overlapping region, the angle range in which the precipitation region is formed is closely related to the angle range in which the adhesion region is formed. Therefore, in the present invention, the fixing method of the master 10 and the conductive ring 22 is defined as described above so that the contact area is formed in a predetermined range.

  As described above, in the mold manufacturing method according to the present invention, in the mold manufacturing using the electroforming method, only two contact regions for the master and the conductive ring are formed in the region where the master and the conductive ring overlap each other. The master and the conductive ring are fixed, and the two contact areas are substantially opposed to each other along the center line of the master. Under such a configuration, the electroformed product can be deposited in a slight gap in a region other than the close contact region in the region where the master and the conductive ring overlap each other, and precipitation can be suppressed in the close contact region. As a result, when the electroformed product is peeled from the master in the stripping process, a region where the cleaning liquid is easy to penetrate and a region where it is difficult to penetrate is formed in the gap between the master and the electroformed product, and foreign matter adheres to the pattern surface of the electroformed product It is possible to lead to a penetration route that is difficult to perform. As a result, in the manufacture of a mold using the electroforming method, it is possible to prevent adhesion of foreign matters on the pattern surface of the electroformed product during the peeling process.

DESCRIPTION OF SYMBOLS 10 Master 12 Conductive layer 14 Electroformed object 15 Overlapping area | region 16 Mold 20 Electroforming jig 21 Cathode main body 22 Conductive ring 23 Holding ring 24 Fixing bolt 25 Pressure measuring film 30 Cleaning container 31 Cleaning liquid 32 Support member 40 Gap 42 of the master and the conductive ring Gap 45 between master and electroformed product Adhesion region 46 Precipitation region 60 Electroforming apparatus 62 Electroforming liquid H Depth of concave portion of concave / convex pattern W Width of convex portion of concave / convex pattern

Claims (4)

A disc-shaped master with a fine uneven pattern formed on one surface is placed on the cathode body,
In a state where an annular conducting ring having an inner diameter smaller than the diameter of the master is fixed concentrically to the one surface of the master, an electroformed product is formed on the one surface,
Peeling the electroformed product from the master in a cleaning solution;
A method of manufacturing a mold for cutting out a portion to be a mold of a predetermined shape from the electroformed product,
The master and the conductive ring are fixed so that only two contact areas for the master and the conductive ring are formed in a region where the master and the conductive ring overlap each other,
The method for manufacturing a mold, wherein the two contact areas are opposed to each other substantially along a center line of the master.   2. The mold manufacturing method according to claim 1, wherein each of the two contact areas is included in an angular range of 60 ° around the center of the master.   The master and the conductive ring are fixed by the pressing ring that presses the conductive ring from above, and is fixed to the cathode body by two fixing members corresponding to the respective positions of the two contact areas. It is performed, The manufacturing method of the mold of Claim 2 characterized by the above-mentioned.   The method for manufacturing a mold according to claim 3, wherein the two fixing members are opposed to each other along a center line of the pressing ring.