JP2009274237A - Transfer method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer method and device, capable of transferring easily micro-fine structure onto a molding member, allowing easily mold-release, and allowing the transfer more quickly than that by injection molding. <P>SOLUTION: The micro-fine structures 2a, 3a formed on stampers 2, 3 are transferred onto the molding member 1. The micro-fine structures 2a, 3a of the stampers 2, 3 are pressed onto the molding member 1 to transfer the micro-fine structures 2a, 3a onto the molding member 1. The mold release of the molding member 1 from the stampers 2, 3 is promoted by repeating cooling and heating of the micro-fine structures 2a, 3a of the stampers 2, 3 at a temperature of a glass transition temperature or less of the molding member 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transfer method and apparatus, and more particularly to a transfer method and apparatus for transferring a fine structure to the surface of a molded member such as a resin.

  As a method of forming a microstructure on the surface of an optical component such as a resin lens, the microstructure is formed on the surface of a mold for injection molding, and the microstructure of the mold is transferred to the surface of the molded product during resin molding. How to do is known.

  When the microstructure is transferred at the time of injection molding, the resin may not be satisfactorily filled into the shape depending on the shape of the microstructure. For example, when forming a fine projection with a large aspect ratio as a microstructure on the surface of a molded product, a fine hole corresponding to the shape of the projection to be formed is formed on the surface of the mold, but at the time of resin injection molding It may be difficult to completely fill such deep fine holes with resin. Further, even if the resin can be filled into the fine structure, there is a possibility that the molded product sticks to the mold and a problem that the mold cannot be released well may occur.

  As a method for releasing a molded product having a fine structure formed on its surface, a technique has been proposed in which the molded product is cooled and contracted with a compressed fluid to promote release (for example, see Patent Document 1). In addition, a technique has been proposed in which the mold is divided into an inner mold and an outer mold so that the inner mold can be moved relative to the outer mold, and a compressed fluid is ejected between the inner mold and the molded product to promote mold release. (For example, refer to Patent Document 2).

  However, when injection molding is used to obtain a molded product having a fine structure transferred, a long time including a cooling time or the like is required in the injection molding cycle, and there is a problem that productivity is not good.

Therefore, it is conceivable to use a stamper to press (stamp) a mold having a fine structure on the surface of the resin member to transfer the fine structure. Since the transfer process using the stamper is only a process of pressing the mold against the resin member without using a molten resin as in the case of injection molding, the transfer can be performed in a much shorter time than the transfer by injection molding.
JP 2000-289064 A JP 2004-351614 A

  In recent years, the demand for resin parts having a fine structure on both sides has been increasing in the optical field and the medical / bio field. In order to meet such a demand, it is conceivable to transfer the fine structure onto both sides by simultaneously pressing both sides with a stamper type. When pressing with a stamper mold to transfer the fine structure to both sides, there is no need for a molding step such as heating until reaching the molten resin and cooling until solidifying. Therefore, the microstructure can be transferred in a shorter time than using injection molding.

  However, there have been few examples of processes in which the microstructure is stamped and stamped on both surfaces of the resin member at the same time, and optimum transfer conditions and transfer methods have not been proposed. In particular, there may be cases where the mold release properties of the stamper type are different between the molds on both sides, but it has not been studied how to mold the molds on both sides. In other words, the releasability depends on the shape and dimensions of the microstructure to be transferred. Therefore, if the microstructures on both sides are different, the operation of the stamper mold and the removal of the transfer molded product must be controlled in consideration of the releasability. So far, the transfer process has not been controlled in consideration of releasability due to the fine structure. Therefore, development of a transfer method capable of realizing an optimal transfer process in double-sided transfer is desired.

  The present invention has been made in view of the above-mentioned problems, and can transfer a fine structure to a molded member easily and can be easily released from the mold, and can perform transfer in a shorter time than transfer by injection molding. It is an object of the present invention to provide a transfer method that can be used.

  In order to achieve the above-described object, according to the present invention, there is provided a transfer method for transferring a microstructure formed on a stamper to a molded member, wherein the microstructure of the stamper is pressed against the molded member, The microstructure is transferred to the molding member, and the microstructure of the stamper is repeatedly cooled and heated at a temperature below the glass transition point of the molding member, thereby facilitating the release of the molding member from the stamper. A transfer method is provided.

  In the transfer method according to the present invention, the microstructure of the stamper and the microstructure transferred to the molding member are repeatedly contracted and expanded, thereby causing surface peeling of the microstructure transferred to the molding member. It is preferable to promote release of the molded member from the stamper. The fine structure of the stamper may be cooled by a local temperature control unit incorporated in a mold to which the stamper is attached. The fine structure of the stamper may be heated by the local temperature control unit. Alternatively, the microstructure of the stamper may be cooled by supplying a coolant to a stamper suction / fixing passage formed in a mold to which the stamper is attached. In this case, the fine structure of the stamper may be heated by a local temperature control unit incorporated in a mold to which the stamper is attached.

  According to the present invention, there is also provided a transfer device for transferring a microstructure to the surface of a molding member, a stamper having the microstructure, a mold to which the stamper is attached, an opening / closing operation of the mold, A control unit for controlling the temperature of the stamper attached to the mold, and the control unit presses the microstructure of the stamper attached to the mold against the molding member to By transferring the temperature of the stamper to the microstructure of the stamper so that cooling and heating are repeated at a temperature below the glass transition point of the molding member. A transfer device is provided that promotes the release of the molded member from the machine.

  In the transfer device according to the present invention, the control unit controls the temperature of the stamper so as to repeat contraction and expansion of the microstructure and the microstructure transferred to the molding member, and transfers the stamper to the molding member. It is preferable to promote mold release of the molded member by causing surface peeling of the fine structure.

  According to the present invention, by locally cooling and heating the portion where the microstructure of the molded member is transferred, the thermal expansion coefficient of the stamper microstructure and the thermal expansion coefficient of the microstructure transferred to the molded member are The mold release can be promoted by utilizing the difference between the two. For this reason, the fine structure transferred to the molded member can be easily released from the stamper. In particular, at the time of mold release, no external force is applied to the microstructure transferred to the molded member. Therefore, the mold can be easily released while maintaining the dimensional accuracy of the microstructure without deforming the transferred microstructure. Can be made.

  Next, embodiments of the present invention will be described with reference to the drawings.

  First, a transfer apparatus that performs a transfer method according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an outline of a transfer apparatus for transferring a fine structure to a molded member by a transfer method according to an embodiment of the present invention.

  In the transfer apparatus shown in FIG. 1, the microstructures 2a and 3a formed on the upper stamper 2 and the lower stamper 3 are formed by pressing the molding member 1 between the upper stamper 2 and the lower stamper 3 and pressing them. It is an apparatus for transferring to both sides of one.

  The molded member 1 is a material that can be plastically deformed by being pressed by the upper stamper 2 and the lower stamper 3, and is a resin member such as a resin plate or a resin sheet, for example. When a plastic optical component is molded by the molded member 1, a transparent resin plate or sheet such as acrylic or polycarbonate is used.

  The upper stamper 2 is a plate-like member formed of, for example, a metal material such as nickel or silicon, and a fine structure 2a is formed on the surface thereof. Further, the upper stamper 2 is provided with a plurality of suction through holes 2b penetrating from the back surface to the front surface. As will be described later, the molding member 1 can be sucked and fixed to the upper stamper 2 by sucking the molding member 1 through the suction through hole 2b.

  The lower stamper 3 has a configuration similar to that of the upper stamper 2, and is a plate-like member formed of, for example, a metal material such as nickel or silicon, and a microstructure 3a is formed on the surface thereof. Further, the lower stamper 3 is provided with a plurality of suction through holes 3b penetrating from the back surface to the front surface. As will be described later, the molding member 1 can be sucked and fixed to the lower stamper 3 by sucking the molding member 1 through the suction through hole 3b.

  The upper stamper 2 is attached to a press upper core 4 which is an upper die. The press upper core 4 is formed with a plurality of stamper suction fixing passages 5 opened to the core mounting surface. The upper stamper 2 can be held on the mounting surface by bringing the upper stamper 2 into contact with the mounting surface and sucking it through the stamper suction fixing passage 5. Therefore, the upper stamper 2 can be detached from the press upper core 4 by releasing the suction.

  The press upper core 4 is formed with a plurality of molding member suction fixing passages 6 that open to positions corresponding to the suction through holes 2 b of the upper stamper 2. The molding member suction fixing passage 6 is connected to the suction through hole 2 b of the upper stamper 2 in a state where the upper stamper 2 is attached to the press upper core 4. Therefore, after attaching the upper stamper 2 to the press upper core 4, the molding member 1 is brought into contact with the upper stamper 2, and the molding member 1 is sucked through the suction through-hole 2 b and the molding member suction fixing passage 6. The molding member 1 can be fixed to the upper stamper 2 by suction.

  Further, when the upper stamper 2 is attached to the press upper core 4, the heater 7 is embedded in the press upper core 4 and the refrigerant passage at a position corresponding to the portion where the microstructure 2 a of the upper stamper 2 is formed. 8 is formed. The heater 7 is a heating wire that generates heat when energized, for example, and can heat only a part of the upper press core 4 corresponding to the portion of the upper stamper 2 where the fine structure 2a is formed. The refrigerant passage 8 is a passage through which a coolant such as cooling water can flow, for example. By flowing the cooling water into the refrigerant passage 8, the press upper core 4 corresponding to the portion where the fine structure 2a of the upper stamper 2 is formed. Only a part of it can be cooled.

  The heater 7 is not limited to a heating wire, and other heating elements such as Peltier elements can also be used. Further, instead of the refrigerant passage 8, another cooling device such as a Peltier element may be used. The heater 7 and the refrigerant passage 8 are provided close to a position corresponding to the portion where the fine structure 2a of the upper stamper 2 is formed, and a local area for heating and cooling the portion of the upper stamper 2 where the fine structure 2a is formed. Functions as a temperature control unit (local temperature control unit).

  The lower stamper 3 is attached to a lower press core 9 which is a lower die. The lower press core 9 is formed with a plurality of stamper suction fixing passages 10 opened on the core mounting surface. The lower stamper 3 can be held on the mounting surface by bringing the lower stamper 3 into contact with the mounting surface and sucking it through the stamper suction fixing passage 10. Therefore, the lower stamper 3 can be removed from the lower press core 9 by releasing the suction.

  The press lower core 9 is formed with a plurality of molding member suction fixing passages 11 opened at positions corresponding to the suction through holes 3 b of the lower stamper 3. The molding member suction fixing passage 11 is connected to the suction through hole 3 b of the lower stamper 3 in a state where the lower stamper 3 is attached to the lower press core 9. Therefore, after attaching the lower stamper 3 to the lower press core 9, the molding member 1 is brought into contact with the lower stamper 3, and the molding member 1 is sucked through the suction through hole 3b and the molding member suction fixing passage 11. The molding member 1 can be sucked and fixed to the lower stamper 3.

  In addition, when the lower stamper 3 is attached to the lower press core 9, the heater 12 is embedded in the lower press core 9 at a position corresponding to the portion where the fine structure 3a of the lower stamper 3 is formed, and the refrigerant passage 13 is formed. The heater 12 is a heating wire that generates heat when energized, for example, and can heat only a part of the lower press core 9 corresponding to the portion of the lower stamper 3 where the fine structure 3a is formed. The refrigerant passage 13 is a passage through which a coolant such as cooling water can flow, for example. By flowing the cooling water through the coolant passage 13, the lower press core 9 corresponding to the portion where the microstructure 3a of the lower stamper 3 is formed. Only a part of it can be cooled.

  The heater 12 is not limited to a heating wire, and other heating elements such as a Peltier element can also be used. Further, instead of the refrigerant passage 13, another cooling device such as a Peltier element can be used. The heater 12 and the refrigerant passage 13 are provided in the vicinity of a position corresponding to the portion of the lower stamper 3 where the fine structure 3a is formed, and are locally heated and cooled in the portion of the lower stamper 3 where the fine structure 3a is formed. Functions as a temperature control unit (local temperature control unit).

  The upper core 4 is provided with an upper core moving mechanism 20 for moving in the vertical direction so that the molded member 1 can be pressed by moving with respect to the lower press core 9. The mechanism is a well-known mechanism, and a specific illustration is omitted for the purpose of simplifying the drawing. Not only the upper press core 4 but also the lower press core 9 may be configured to be movable up and down. In this case, the lower press core 9 is provided with a lower core moving mechanism 22 for moving in the vertical direction so that it can move with respect to the press upper core 4 and press the molding member 1. The vertical mechanism is a well-known mechanism, and a specific illustration is omitted for the purpose of simplifying the drawing.

  The operations of the upper core moving mechanism 20 and / or the lower core moving mechanism 22 are controlled by a control unit 24 that controls the entire transfer apparatus. The control unit 24 controls the ascent and descent of the upper press core 4 and / or the lower press core 9, and the suction fixing of the upper stamper 2 to the upper press core 4, the suction fixing of the lower stamper 3 to the lower press core 9, The suction fixing to the upper stamper 2 of the molding member 1, the fixing to the lower stamper 3 of the molding member 1, the heating and cooling by the local temperature control unit incorporated in the upper core 4 and the lower pressing core 9 are controlled. Further, the control unit 24 also controls the supply of the refrigerant to the stamper suction fixing passage during a mold release step described later. Control of heating by the local temperature control unit is performed by energization control of the heater. The stamper suction / fixing control is performed by controlling the opening / closing of an on-off valve (not shown) connected to the stamper suction / fixing passages 5 and 10. The suction and fixation to the upper stamper 2 and the lower stamper is performed by controlling the opening and closing of an on-off valve (not shown) connected to the molding member suction and fixing passages 6 and 11. Further, the refrigerant is supplied to the stamper suction fixing passages 5 and 10 by controlling an on-off valve (not shown).

  Next, an example of a transfer method for transferring the fine structure to the molded member 1 using the transfer apparatus shown in FIG. 1 will be described. 2 and 3 are diagrams showing a transfer process when transferring the fine structure to the molded member 1 using the transfer apparatus shown in FIG.

  First, the lower stamper 3 is placed on the lower press core 9 and the upper stamper 2 is placed over the lower stamper 3. Then, the press upper core 4 is lowered, and the upper stamper 2 and the lower stamper 3 are sandwiched between the press upper core 4 and the press lower core 9. At this time, the pressing force by the upper press core 4 and the lower press core 9 may be a slight force. With the upper stamper 2 and the lower stamper 3 being sandwiched between the upper press core 4 and the lower press core 9, as shown in FIG. The stamper 2 is sucked and fixed to the upper press core 4, and the lower stamper 3 is sucked and fixed to the lower press core 9 through the stamper suction fixing passage 10 of the lower press core 9.

  When the upper stamper 2 and the lower stamper 3 are fixed, when the press upper core 4 is raised as shown in FIG. 2B, the upper stamper 2 rises together with the press upper core 4. Therefore, the molding member 1 is placed on the lower stamper 3 and is sucked through the suction through hole 3b and the molding member suction fixing passage 11 and fixed to the lower stamper 3.

  When the molding member 1 is fixed on the lower stamper 3, as shown in FIG. 3, the upper stamper 2 is lowered, the molding member 1 is sandwiched between the upper stamper 2 and the lower stamper 3, and the molding member 1 is pressed. Gradually increase the pressing force. At this time, the heater 7 of the upper press core 4 and the heater 12 of the lower press core 9 are energized to locally heat the upper press core 4 and the lower press core 9. The portion heated by the heater 7 is a portion corresponding to the portion where the fine structure 2a of the upper stamper 2 is formed. Therefore, the portion of the upper stamper 2 where the fine structure 2a is formed is also heated by the heater 7 to a predetermined temperature. The predetermined temperature is a temperature at which the molded member 1 is softened and the fine structure 2a is easily transferred. Similarly, the portion heated by the heater 12 is a portion corresponding to the portion where the fine structure 3a of the lower stamper 3 is formed. Accordingly, the portion of the lower stamper 3 where the fine structure 3a is formed is also heated by the heater 12 to a predetermined temperature. The predetermined temperature is a temperature at which the molded member 1 is softened and the fine structure 3a is easily transferred. Specifically, the stampers 2 and 3 are heated to a temperature equal to or higher than the glass transition point.

  Thus, when transferring the microstructures 2a and 3a, only the transferred portion of the molding member 1 is locally heated and softened, so that the microstructures 2a and 3a can be easily transferred to the molding member 1. Even if the microstructures 2a and 3a are concave and convex with a high aspect ratio, the softened molded member 1 can be sufficiently filled to the back of the recesses, and the microstructures 2a and 3a are accurately transferred. be able to.

  When the transfer is completed within a predetermined time, heating by the heaters 7 and 12 is stopped, and then the process proceeds to a mold release process. FIG. 4 is a flowchart of a mold release process in which the mold is repeatedly released by cooling and heating by the local temperature control unit. FIG. 5 is a timing chart of the mold release operation in which the mold is repeatedly released by cooling and heating by the local temperature control unit. In the mold release step shown in FIG. 4, the mold is released first from the lower stamper 3, but may be released first from the upper stamper 2.

  When the mold release process is started, first, the pressing force (transfer pressure) by the upper stamper 2 and the lower stamper 3 is reduced (step S1), and finally the pressing force is set to zero or almost no pressing force is applied. Next, a refrigerant is passed through the refrigerant passage 13 of the local temperature control unit of the lower press core 9 to cool the microstructure 3a of the lower stamper 3 from the back side of the lower stamper 3 (step S2). Cooling may be started before the pressing force becomes zero, and the pressing force may be zero when the cooling in step S2 is completed. Since the lower stamper 3 is heated to a temperature not lower than the glass transition point of the molded member 1 in the transfer step, the surface temperature of the lower stamper 3 (the surface temperature of the fine structure 3a) is not higher than the glass transition point by cooling in step S2. Cool until the temperature reaches. At this time, as shown in FIG. 5A, the surface temperature of the lower stamper 3 is cooled to a temperature between the glass transition point and room temperature without being lowered to room temperature all at once. In the present embodiment, a cooling time until the surface temperature of the microstructure 3a reaches a temperature between the glass transition point and room temperature is determined in advance, and the cooling is stopped when a predetermined cooling time t1 has passed. The surface temperature of the fine structure 3a may be estimated by detecting the temperature of the lower stamper 3.

  In step S2, cooling by the local temperature adjustment unit is performed while maintaining the state in which the lower stamper 3 is sucked and fixed to the lower press core 9 through the stamper suction fixing passage 10 and is in close contact therewith. Since the local temperature control unit is incorporated in the lower core 9 of the press, the heat transfer from the lower stamper 3 to the lower core of the press is efficiently performed by keeping the lower core 9 and the lower stamper 3 in close contact with each other, thereby cooling effect. Is to increase

  When the first cooling is completed, the heater 12 of the local temperature control unit of the lower core 9 of the press is energized to heat the lower stamper 3 from the back side (step S3), and the surface temperature of the lower stamper 3 (fine structure 3a). The surface temperature). At this time, the temperature of the surface of the fine structure 3a is raised to a temperature not exceeding the glass transition point. In this embodiment, the lower stamper 3 is heated by energizing the heater 12 for a predetermined heating time. When the first heating in step S3 is completed, the process proceeds to step S4.

  In step S4, it is determined whether cooling and heating have been repeated n times a predetermined number of times. If it is determined in step S4 that the cooling and heating n times has not been repeated a predetermined number of times, the process returns to step S2, cooling in step S2 (second cooling) and heating in step S3 (second heating). And the determination in step S4 is performed again.

  On the other hand, if it is determined in step S4 that the cooling and heating have been repeated n times, it is determined that the molding member 1 has been released from the lower stamper 3, and the process proceeds to step S5. That is, if cooling and heating of the lower stamper 3 are repeated n times a predetermined number of times, it is determined that the release of the molded member 1 from the lower stamper 3 has been completed.

  The lower stamper 3 and the molded member 1 are not completely separated when it is determined in step S4 that n times of cooling and heating have been repeated, but when viewed microscopically, the fine transferred to the molded member 1 Surface peeling occurs in the structure, and the fine structure transferred to the molding member 1 is released from the fine structure 3 a of the lower stamper 3. The surface layer peeling is caused by repeating cooling and heating in the microstructure 3a of the lower stamper 3 in particular. That is, since the coefficient of thermal expansion of the material (resin) of the molded member 1 is larger than the coefficient of thermal expansion of the material (metal) of the lower stamper 3, the close contact portion between the molded member 1 and the lower stamper 3 by repeating cooling and heating. Stress occurs due to the difference in thermal expansion coefficient, and surface peeling is induced.

  Surface peeling is unlikely to occur with a single cooling and heating, and gradually proceeds by repeating the cooling and heating a plurality of times. The predetermined number n is determined in advance by experiments or the like, and an appropriate number may be set according to the shape and size of the microstructure 3a, the material of the molded member 1, the material of the lower stamper 3, and the like.

  When the release of the molded member 1 from the lower stamper 3 is completed, the molded member 1 is then released from the upper stamper 2 (step S5). That is, in step S5, the same processing as steps S2 to S4 in releasing the lower stamper 3 is performed, and cooling and heating of the upper stamper 2 are repeated m times a predetermined number of times. If the shape and size of the microstructure 2a of the upper stamper 2 are the same as the shape and size of the microstructure of the lower stamper, n = m. However, the shape and size of the microstructure 2a, the material of the molded member 1, the upper stamper 2 An appropriate number of times may be set depending on the material of the material.

  When it is determined that the forming member 1 has been released from the upper stamper 2 after the processing in step S5 is completed, air is supplied to the forming member suction fixing passage 6 of the upper core 4 of the press (step S6). While completely releasing the member 1 from the upper stamper 2, the upper press core 4 is raised as shown in FIG. 6 (step S7).

  Subsequently, air is supplied to the molding member suction fixing passage 11 of the lower press core 9 (step S8), and the molding material is taken out as shown in FIG. 7 while completely releasing the molding member 1 from the lower stamper 3. (Step S9). This completes the mold release process.

  After the molded member 1 is taken out, as shown in FIG. 8, compressed gas (here, compressed air) is injected toward the lower stamper 3 through the molded member suction fixing passage 6 and the suction through hole 2 b of the upper stamper 2. Then, the residue remaining in the lower stamper 3 is blown away to remove the compressed gas (here, compressed air) to the upper stamper 2 through the molding member suction fixing passage 11 and the suction through hole 3b of the lower stamper 3. The residual material remaining on the upper stamper 3 is blown off and removed.

  In the transfer step and the release step described above, only the upper press core 4 is raised and lowered, but the lower press core 9 may be raised and lowered, or both may be raised and lowered.

  Further, although the microstructures 2a and 3a are transferred to both the upper and lower surfaces of the molding member 1, the microstructure may be transferred to only one of the upper and lower surfaces of the molding member 1 by a similar method.

  Next, another example of the mold release process will be described. FIG. 9 is a flowchart of a mold release process in which the mold is released by repeatedly cooling and heating while supplying the refrigerant from the stamper suction fixing passage. FIG. 10 is a timing chart of the mold release operation in which the mold is released by repeating cooling and heating while supplying the refrigerant from the stamper suction fixing passage. In the mold release step shown in FIG. 9, the mold is released first from the lower stamper 3. However, the mold may be released first from the upper stamper 2.

  When the mold release process is started, first, the pressing force (transfer pressure) by the upper stamper 2 and the lower stamper 3 is reduced (step S11), and finally the pressing force is set to zero or almost no pressing force is applied. Next, the suction from the stamper suction fixing passage 10 of the lower press core 9 is released to make the suction force acting on the lower stamper 3 zero (step S12). As a result, the close contact between the lower press core 9 and the lower stamper 3 is released, and gas can easily enter between the lower press core 9 and the lower stamper 3.

  Next, a coolant such as low-temperature air or gas is supplied to the stamper suction fixing passage 10 to cool the lower stamper 3 (step S13). The refrigerant supplied to the stamper suction fixing passage 10 diffuses between the lower press core 9 and the lower surface of the lower stamper 3, and the lower surface of the lower stamper 3 is cooled by the refrigerant. Thereby, the fine structure 3 a of the lower stamper 3 is cooled from the back side of the lower stamper 3. Since the lower stamper 3 is heated to a temperature not lower than the glass transition point of the molded member 1 in the transfer step, the surface temperature of the lower stamper 3 (the surface temperature of the fine structure 3a) is not higher than the glass transition point by cooling in step S13. Cool until the temperature reaches. At this time, as shown in FIG. 10A, the surface temperature of the lower stamper 3 is cooled to a temperature between the glass transition point and room temperature without being lowered to room temperature at once. In the present embodiment, a cooling time until the surface temperature of the microstructure 3a reaches a temperature between the glass transition point and room temperature is determined in advance, and the cooling is stopped when a predetermined cooling time t1 has passed. The surface temperature of the fine structure 3a may be estimated by detecting the temperature of the lower stamper 3.

  When the first cooling is completed, the heater 12 of the local temperature control unit of the lower core 9 of the press is energized to heat the lower stamper 3 from the back side (step S14), and the surface temperature of the lower stamper 3 (fine structure 3a). The surface temperature). At this time, the temperature of the surface of the fine structure 3a is raised to a temperature not exceeding the glass transition point. In this embodiment, the lower stamper 3 is heated by energizing the heater 12 for a predetermined heating time. When the first heating in step S14 is completed, the process proceeds to step S15. The process of step S15 is the same as the process of step S4 in FIG. 4 described above, and it is determined whether or not cooling and heating have been repeated n times a predetermined number of times. If it is determined in step S15 that the cooling and heating n times has not been repeated a predetermined number of times, the process returns to step S13, cooling in step S13 (second cooling) and heating in step S14 (second heating). And the determination in step S15 is made again.

  On the other hand, if it is determined in step S15 that the cooling and heating have been repeated n times a predetermined number of times, it is determined that the molding member 1 has been released from the lower stamper 3, and the process proceeds to step S16. That is, if cooling and heating of the lower stamper 3 are repeated n times a predetermined number of times, it is determined that the release of the molded member 1 from the lower stamper 3 has been completed.

  When it is determined in step S15 that n times of cooling and heating have been repeated, the lower stamper 3 and the molded member 1 are not completely separated, but microscopically transferred to the molded member 1 when viewed microscopically. Surface peeling occurs in the structure, and the fine structure transferred to the molding member 1 is released from the fine structure 3 a of the lower stamper 3.

  If it is determined in step S15 that the predetermined number of times of cooling and heating has been repeated, suction is performed from the stamper suction fixing passage 10 of the lower press core 9 and the lower stamper 3 is suction fixed to the lower press core 9 (step S16). . Then, the suction from the stamper suction fixing passage 5 of the press upper core 4 is released, and the suction force acting on the upper stamper 2 is made zero (step S7). The upper stamper 2 is also subjected to the same processing as steps S13 to S15 described above, and cooling and heating of the upper stamper 2 are repeated a predetermined number of times (step S18).

  If it is determined that the upper stamper 2 has been cooled and heated a predetermined number of times, the upper stamper 2 is sucked from the stamper suction fixing passage 5 and the upper stamper 2 is sucked and fixed to the upper presser core 4 (step S19). ). After that, the same process as the process of steps S6 to S9 in FIG. 4 is performed, the molded member 1 is taken out, and the mold release process is completed. Steps S20 to S23 in FIG. 9 correspond to steps S6 to S9 in FIG.

  After the molded member 1 is taken out, as shown in FIG. 8, compressed gas (here, compressed air) is injected toward the lower stamper 3 through the molded member suction fixing passage 6 and the suction through hole 2 b of the upper stamper 2. Then, the residue remaining in the lower stamper 3 is blown away to remove the compressed gas (here, compressed air) to the upper stamper 2 through the molding member suction fixing passage 11 and the suction through hole 3b of the lower stamper 3. The residual material remaining on the upper stamper 3 is blown off and removed.

  In the mold release step described above, only the upper press core 4 is raised and lowered, but the lower press core 9 may be raised and lowered, or both may be raised and lowered. Further, although the microstructures 2a and 3a are transferred to both the upper and lower surfaces of the molding member 1, the microstructure may be transferred to only one of the upper and lower surfaces of the molding member 1 by a similar method.

  As described above, the cooling by the local temperature control unit can be used to cool the stamper at the time of mold release (the mold release process shown in FIG. 4), but the cooling by the local temperature control unit is not sufficient. When the time is long, the cooling time can be shortened by flowing the coolant through the stamper suction fixing passage to directly cool the stamper (the mold release process shown in FIG. 9). It can be shortened.

It is sectional drawing which shows the outline | summary of the transfer apparatus which transfers a fine structure to a shaping | molding member with the transfer method by one Embodiment of this invention. It is a figure which shows the state of the transfer apparatus in a transfer process. It is a figure which shows the state of the transfer apparatus in a transfer process. It is a flowchart of an example of the mold release process performed following a transfer process. It is a timing chart of the mold release operation | movement in the mold release process shown in FIG. It is a figure which shows the state of the transfer apparatus in a mold release process. It is a figure which shows the state of the transfer apparatus in a mold release process. It is a figure which shows the state of the transfer apparatus in a cleaning process. It is a flowchart of the other example of the mold release process performed following a transfer process. 10 is a timing chart of a mold release operation in the mold release process shown in FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molding member 2 Upper stamper 2a Fine structure 2b Suction through hole 3 Lower stamper 3a Fine structure 3b Suction through hole 4 Core on press 5,10 Stamper suction fixing passage 6,11 Molding member suction fixing passage 7,12 Heater 8, 13 Refrigerant passage 9 Press lower core 20 Upper core moving mechanism 22 Lower core moving mechanism 24 Control unit

Claims (8)

A transfer method for transferring a microstructure formed on a stamper to a molded member,
Pressing the microstructure of the stamper against the molded member, transferring the microstructure to the molded member,
A transfer method characterized by promoting the release of the molding member from the stamper by repeatedly cooling and heating the microstructure of the stamper at a temperature below the glass transition point of the molding member. The transfer method according to claim 1,
The shrinkage and expansion of the microstructure transferred to the molding member and the microstructure transferred to the molding member are repeated to cause surface peeling of the microstructure transferred to the molding member. A transfer method characterized by promoting mold release. The transfer method according to claim 2,
A transfer method, wherein the microstructure of the stamper is cooled by a local temperature control unit incorporated in a mold to which the stamper is attached. The transfer method according to claim 3, wherein
A transfer method, wherein the fine structure of the stamper is heated by the local temperature control unit. The transfer method according to claim 2,
A transfer method, wherein the fine structure of the stamper is cooled by supplying a coolant to a stamper suction fixing passage formed in a mold to which the stamper is attached. The transfer method according to claim 5,
A transfer method characterized in that the fine structure of the stamper is heated by a local temperature control unit incorporated in a mold to which the stamper is attached. A transfer device for transferring a microstructure to the surface of a molded member,
A stamper having the microstructure;
A mold to which the stamper is attached;
A control unit for controlling the temperature of the stamper attached to the mold, and an opening / closing operation of the mold,
The control unit presses the microstructure of the stamper attached to the mold against the molding member, transfers the microstructure to the molding member, and then applies the microstructure to the stamper with respect to the microstructure. A transfer device that promotes release of the molding member from the stamper by controlling the temperature of the stamper so that cooling and heating are repeated at a temperature below the glass transition point of the molding member. The transfer device according to claim 7,
The control unit controls the temperature of the stamper so as to repeatedly shrink and expand the microstructure of the stamper and the microstructure transferred to the molding member, and peels the surface layer of the microstructure transferred to the molding member. A transfer device that promotes release of the molding member by generating

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