JP4900980B2 - Method for forming fine through hole of resin sheet and fine structure transfer molding apparatus - Google Patents

Description

  The present invention relates to a fine through-hole forming method for forming fine through-holes in a resin sheet and a microstructure transfer molding apparatus that can be suitably used for the implementation of the method.

  Resin sheets having through-holes are used, for example, as medical applications, transdermal drug delivery systems using microneedle arrays, biosensors, medical polymer membranes (blood purification, hemodialysis, artificial liver, membrane-type artificial lung, virus removal membrane) Etc.), and is being used for artificial blood vessels. In addition, as electrical and electronic materials, utilization for battery separators, porous sensors, liquid crystal optical display elements, and the like has been promoted.

  As a method for producing a resin sheet having such a through hole, first, an injection molding method or a thermal imprint method can be cited. As shown in FIG. 7, the injection molding method is a method of forming a projecting pin on a mold, injecting a molten resin around the pin, cooling the mold, and then opening and removing the mold. On the other hand, as shown in FIG. 8, the thermal imprint method softens a solid thermoplastic resin film formed on a substrate of Si, glass, quartz or the like above its glass transition temperature. Similarly, the heated stamper protrusions are pressed against the resin to deform under pressure, and after cooling and releasing the mold, the remaining film between the protrusions and the substrate is removed by reactive ion etching of oxygen. This is a construction method in which the surface is exposed and the substrate and the resin are peeled off to form a through hole.

  Further, there is a precision machining method in which a fine through hole is formed by pressing a resin film using a mold having needle-like protrusions as shown in FIG.

  Furthermore, as a method for producing a microstructured body having a through hole, for example, Patent Document 1 discloses that a film made of a polymer material such as PET, PES, PC, PI is irradiated with a laser beam to perform perforation processing. A method for producing a characteristic fine particle classification filter has been proposed.

  In Patent Document 2, a liquid lens material having a predetermined translucency and a predetermined viscosity and curable is dropped or injected into each through hole of the substrate on which a plurality of through holes are formed. A method of manufacturing a microlens array has been proposed in which each lens is manufactured by positioning the lens material in each through-hole. In the specification, it is described that the through-hole can be opened by ultra-precision cutting, laser processing, focused ion beam processing, laser etching processing, micro-discharge processing, electron beam drawing, or the like depending on the size. Yes.

  Patent Document 3 discloses that a highly accurate three-dimensional microstructure having an inclined side wall in a resin layer that can be electroformed and used as a fine mold can be mass-produced at low cost by a simple X-ray exposure system. A method is provided. Patent Document 4 proposes a manufacturing method in which a thin film microfilter is manufactured by embossing a resin and forming a through hole by performing chemical etching or laser ablation on the embossed recess bottom.

  Patent Document 5 discloses a method in which a plastic film is placed in a gap between a needle sword mountain roll and a compressed air blowing port, and compressed air is blown onto the film and pressed against the needle sword mountain roll to continuously process fine holes with a needle. A fine hole processing facility for plastic films has been proposed in which the needle root diameter is 1 mm or less and the average diameter of openings provided in the plastic film is 500 μm or less.

  Patent Document 6 describes an apparatus having a pair of rollers for punching a belt-like sheet, particularly a plastic sheet. The roller pair is composed of a roller with a needle having a needle provided in a radial direction with respect to the outer peripheral surface thereof, and a counter roller held in contact with the roller with the needle. The face is provided with a lining, for example an elastic outer layer, which allows the needle tip to be penetrated.

Japanese Patent Laid-Open No. 10-118569 JP2003-4909 JP 2008-89617 Special table 2002-533236 gazette JP 2004-344986 JP Japanese National Patent Publication No. 11-508830

  What is important for industrial production of resin sheets with micropores is the accuracy of the micropore shape (roundness, hole diameter, shape or depth, absence of burrs and sink marks), and micropore shape. Productivity (e.g., depth, diameter, hole shape), durability of stamper projections (wear, breakage, deformation), productivity and economics such as yield and molding cycle time. And for medical applications and electrical / electronic materials applications, various types of resin materials with various characteristics (types such as thermoplasticity, thermosetting, UV curable, and various physical properties such as heat resistance and mechanical strength) Are used depending on the application, and there is a tendency that a large area having a large number of fine holes with high accuracy is required instead of a single one. Therefore, there is a demand for a fine through-hole molding method that is excellent in dimensional accuracy and shape accuracy, which is a resin sheet of various types or various thicknesses, and in which fine through-holes are uniformly formed over a large area.

  In response to such demands, the injection molding method is highly productive, but a high pressure of 20 MPa or more acts in the mold, and the protrusion filled in the mold fills the mold with resin. Since a high shearing force acts on the pin, the protruding pin is liable to be worn, broken or collapsed, and there is a problem in its durability. Also, a weld line is likely to occur when the resin flows around the protrusion. Due to the durability of the pin, it is impossible to make a hole with a diameter of several hundred μm or less. Then, there is a problem that the resin easily enters the fitting portion between the hole of the mold and the pin, and burrs are easily generated, and at the same time, it is not easy to open a complete through hole by leaving a remaining film. Further, the thickness obtained as a molded product is 0.3 mm or more, and there is a problem that it is difficult to obtain a thin, large-area resin sheet-shaped molded body having uniform fine holes.

  As shown in FIG. 8 (b), the thermal imprint method requires a very large pressing force in order to pressure-deform the solid thermoplastic resin film heated and softened near the glass transition point with protrusions. However, the tip end of the protrusion of the stamper is likely to be worn, worn or broken. Further, in order to remove the residual film shown in FIG. 8C by reactive ion etching of oxygen, expensive equipment and extra process time are required, so that productivity is low and equipment is expensive. There's a problem. Furthermore, in order to heat a solid resin from room temperature to glass transition temperature by heat transfer from a mold, there is a problem that it takes a long time of several minutes and productivity is low.

  When a solid resin film at room temperature is perforated with fine protrusions on the mold, it is not easy to drill fine through-holes and burrs are likely to occur, as shown in FIGS. There is a problem. In particular, when a resin with low rigidity is a processing target, there is a problem that it is difficult to open a through hole.

  The method described in Patent Documents 1 to 3 that uses a laser, X-ray, electron beam, or the like to open a fine through-hole requires large-scale equipment, as well as a through-hole whose cross-sectional shape changes, such as a cone. There is a problem that it is difficult. In particular, in order to perforate a sheet resin having a large area, a great deal of time is required in proportion to the number of holes. The hot embossing method described in Patent Document 4 requires an ablation treatment as described in Patent Document 4, a resin film with low rigidity cannot have a through-hole, has a short mold life, Or there is a problem that it takes time to heat and cool the mold and the productivity is poor.

  The method shown in Patent Document 5 and Patent Document 6 is a method of making a hole in a solid resin such as a solid sheet or a film, as in the case of the precision machining method described above. Therefore, there is a problem that burrs are likely to be generated at the drilled portion, the edge portion of the hole is easily rounded, and the shape accuracy is not obtained. Further, when the solid resin is stretched and deformed, there is a problem that the holes are not easily formed, and a part having no holes is generated. As shown in Patent Document 5, when the solid resin sheet is pressed against the sword mountain roll with wind pressure, it is difficult to apply the wind pressure evenly on the target area, which is not suitable for precise drilling.

  Further, in the methods shown in Patent Document 5 and Patent Document 6, the shape of the hole is restricted by the shape of the protrusion of the stamper, and a cylindrical or trapezoidal hole whose tip is not needle-shaped cannot be formed. There is. In addition, since a large stress acts on the tip of the protrusion of the stamper, wear, settling, etc. are likely to occur. If the ratio of the hole diameter to depth (aspect ratio) exceeds 1, or a highly elastic solid resin is used. When processing, the buckling strength of the protrusion of the stamper becomes a problem. For example, when drilling is performed with needle-like protrusions having a high aspect ratio such as a diameter of 100 μm and a height of 1 mm, the needle-like protrusions are likely to buckle and break. In addition, since the holes are perforated on the rotating roller, a slight inclination occurs in the insertion direction and the extraction direction of the protrusions in the film, the relative angle of the film changes, and the protrusion shape is faithfully transferred to the hole shape. There is a problem that can not be.

  In view of such a conventional problem, the present invention can open through holes of various shapes such as a needle shape, a cone shape, or a trapezoid shape, and there is almost no burr or hole rounding or shape defect. An object of the present invention is to propose a method for producing a resin sheet having excellent precision and having uniform fine pores over a large area. Also, to propose a production method that can efficiently produce a resin sheet having a through-hole, with a low possibility of causing wear, breakage or buckling failure of the protrusions of the mold, and a long life of the mold. With the goal. Furthermore, it aims at proposing the fine through-hole shaping | molding method of the resin sheet of the wide application range which can pierce | punch the resin sheet of various materials regardless of a thermoplastic resin and a thermosetting resin.

  The method for forming fine through-holes of a resin sheet according to the present invention includes a step of supplying a resin sheet onto a heated stamper having fine protrusions, a step of supplying a molten resin medium onto the resin sheet, and the molten resin medium Pressing the softened resin sheet through the step, punching the resin sheet with the fine protrusions, cooling the molten resin medium and the resin sheet while pressing, the solidified molten resin medium and the Peeling off the processed resin sheet from the stamper; and peeling off the processed resin sheet and the solidified molten resin medium.

  In the above invention, when the resin sheet is a thermoplastic resin, the molten resin medium may have a melting point Tbm that satisfies Tbm ≦ Tpm with respect to a melting point Tpm of the resin sheet. The temperature Tbf supplied above may be Tbm <Tbf ≦ Tpm. In addition, each said temperature and the temperature shown below show (degreeC) temperature.

  In the above invention, the solidified molten resin medium and the processed resin sheet can be separated from the stamper by adjusting the temperature of the stamper. And the temperature adjustment of the stamper is used to press the molten resin medium and the molten resin medium against the temperature of the molten resin medium and the adhesive force characteristics of the resin sheet and the stamper with respect to the temperature of the stamper. The separation temperature Tse at which the solidified molten resin medium and the processed resin sheet are separated from the stamper is preferably Tse ≦ Tbm−10.

  In the above invention, the molten resin medium is preferably supplied by applying a molten resin medium discharged from a T die.

  The fine protrusion has a cone, a pyramid, a cylinder, a cylinder having a hemispherical tip, a cylinder having a conical tip, or a cone or a pyramid shape having a pyramidal tip, and a height of 1 μm to 3 mm. The average diameter of the cross section may be φ1 μm to φ1 mm.

  The resin sheet has a thickness of 1 μm to 1 mm, the molten resin medium has a thickness of 50 μm to 3 mm, and the fine protrusion has a height exceeding the thickness of the resin sheet, and the sum of the thickness of the resin sheet and the molten resin medium It can be less than.

  The material of the molten resin medium is methacrylic resin, polycarbonate resin, polystyrene resin, cyclic polyolefin resin, polyethylene terephthalate resin, polyethylene naphthalate resin / polylactic acid resin, polyethylene resin, polypropylene resin, thermoplastic elastomer resin, methacrylic butadiene. A styrene copolymer, an acrylic / butadiene / styrene copolymer, or a polyoxymethylene resin can be used.

  The resin sheet material is polytetrafluoroethylene (PTFE) resin, polyamide resin, polyimide resin, polyamide-imide resin, epoxy resin, unsaturated polyester resin, glass fiber reinforced resin (GFRP), carbon fiber reinforced resin (CFRP), Methacrylic resin, polycarbonate resin, polystyrene resin, cyclic polyolefin resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polylactic acid resin, polyethylene resin, polypropylene resin, thermoplastic elastomer resin, methacrylic butadiene styrene copolymer, acrylic butadiene A styrene copolymer or a polyoxymethylene resin can be used.

  Such an invention can be suitably implemented by the following microstructure transfer molding apparatus. That is, the microstructure transfer molding apparatus according to the present invention is a press-type microstructure transfer molding apparatus for manufacturing a microstructure molded body having a through hole, and includes a lower mold having temperature adjusting means, and the lower mold An upper die having a temperature adjusting means, a stamper having fine protrusions installed on the lower die, and a resin sheet for forming the microstructured compact are supplied onto the stamper. And a medium supply device for supplying a molten resin medium onto the resin sheet.

  In the invention relating to the microstructure transfer molding apparatus, the medium supply device adjusts so that the molten resin medium supplied onto the resin sheet is supplied to a predetermined thickness with respect to the thickness of the resin sheet. It is preferable to have a thickness adjusting means.

  According to the present invention, it is possible to produce a high-quality resin sheet that has fine through-holes having various cross-sectional shapes and has almost no burrs, rounded bottoms, or defective shapes. Moreover, the resin sheet which has the fine hole of a uniform property over a large area can be manufactured. In addition, the present invention can prolong the life of the stamper, reduce the risk of buckling failure of the fine protrusions of the stamper, and efficiently produce a resin sheet having fine through holes.

It is a conceptual diagram explaining the fine through-hole shaping | molding method of the resin sheet which concerns on this invention. It is explanatory drawing which shows the example of the stamper which has the various fine protrusion used in the invention shown in FIG. It is explanatory drawing which shows each process of the fine through-hole shaping | molding method of the resin sheet which concerns on this invention. It is explanatory drawing of the T-die main-body part which supplies a molten resin medium. It is a schematic diagram explaining the method to peel the punched resin sheet from a stamper. It is explanatory drawing which shows the shape of the fine protrusion of the stamper used in the Example. It is explanatory drawing of a prior art. It is explanatory drawing of another prior art. It is explanatory drawing of another prior art.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram illustrating a resin sheet fine through-hole forming method according to the present invention. As shown in FIG. 1, the resin sheet is formed with a fine through-hole forming method in a state in which a resin sheet 50 having a molten resin medium 55 attached on a heated stamper 30 having fine protrusions 35 is mounted (a ) And pressing the resin sheet 50 through the molten resin medium 55 (b) to open a fine through hole in the resin sheet 50. Thereby, this fine through-hole forming method can punch the resin sheet 50 in an optimal state without damaging the fine protrusions 35, and can make a highly accurate through-hole.

  In the fine through-hole forming method, the molten resin medium 55 is a viscoelastic body that is maintained at a predetermined temperature and has appropriate compressibility and fluidity. And since this molten resin medium 55 has a constant pressure specific heat twice as high as that of metal and a low thermal conductivity of 1/100 or less, it can be in a softened state optimal for perforating the resin sheet 50. . In addition, since the molten resin medium 55 functions as a reinforcing member and a buffer member when the resin sheet 50 is perforated, the resin sheet 50 may be a resin having low rigidity or a thin resin. A highly accurate through hole can be formed, and damage to the fine protrusions 35 of the stamper 30 can be prevented and wear can be suppressed.

  When the resin sheet 50 is thin and has low rigidity, the molten resin medium 55 has a required thickness as necessary to ensure the rigidity, and the fine protrusions 35 penetrating the resin sheet 50 are formed inside the resin sheet 50. It is preferable that the thickness of the fine protrusions 35 be maintained to prevent damage to the tips of the fine protrusions 35. For this reason, it is preferable that the thickness of the molten resin medium 55 can be controlled with high accuracy.

  Melted resin medium 55 is methacrylic resin, polycarbonate resin, polystyrene resin (PS), cyclic polyolefin resin, polyethylene terephthalate resin, polyethylene naphthalate resin / polylactic acid resin, polyethylene resin (PE), polypropylene resin (PP), thermoplastic An elastomer resin, a methacryl / butadiene / styrene copolymer, an acrylic / butadiene / styrene copolymer, or a polyoxymethylene resin can be used.

  As described above, the resin sheet 50 may be a resin having low rigidity or a thin resin. For example, a resin sheet having a thickness of several μm to 1 mm may be used. The resin sheet 50 may be a thermoplastic resin or a thermosetting resin.

  Resin sheet 50 consists of polytetrafluoroethylene (PTFE) resin, polyamide resin, polyimide resin, polyamide / imide resin, epoxy resin, unsaturated polyester resin, glass fiber reinforced resin (GFRP), carbon fiber reinforced resin (CFRP), methacrylic resin Resin, polycarbonate resin, polystyrene resin, cyclic polyolefin resin (COP), polyethylene terephthalate resin, polyethylene naphthalate resin (PEN), polylactic acid resin, polyethylene resin, polypropylene resin, thermoplastic elastomer resin, methacrylic butadiene styrene copolymer Polymers, acrylic / butadiene / styrene copolymers, or polyoxymethylene resins can be used.

  A known stamper 30 can be used. However, the fine protrusions 35 of the stamper 30 can have various shapes such as a cone, a pyramid, a cylinder, a cylinder having a hemispherical tip, a cylinder having a conical tip, or a cone or a pyramid shape having a pyramid tip. can do. For example, as shown in FIG. 2, the fine protrusion 35 is a cylinder or prismatic shape (a), a cone or pyramid shape (b), a cylinder or a prism, and has a bullet-like shape (c) or a bowl-like shape (d). , A truncated cone or a truncated pyramid (e), or a special shape ((f), (g)) shown in FIG. 2 (b). It can be made into various shapes, such as the shape of forming the shape.

  The fine protrusions 35 having a height of 1 μm to 3 mm and an average cross-sectional diameter of φ1 μm to φ1 mm can be used. Further, the fine protrusion 35 having a high aspect ratio such as a diameter of 100 μm and a height of 1 mm can be used. In order to prevent damage to the tip of the fine protrusion 35, the height of the fine protrusion 35 should exceed the thickness of the resin sheet 50 and be less than the sum of the thickness of the resin sheet 50 and the molten resin medium 55. Good.

  The heating temperature of the stamper 30 is selected in consideration of the supply temperature of the molten resin medium 55 onto the resin sheet 50, so that the resin sheet 50 is in an optimum softened state for performing perforation processing. Therefore, when the resin sheet 50 is a thermoplastic resin, it is preferable to use a molten resin medium 55 whose melting point Tbm is Tbm ≦ Tpm with respect to the melting point Tpm of the resin sheet. The temperature Tbf for supplying the molten resin medium 55 onto the resin sheet 50 is preferably Tbm <Tbf ≦ Tpm.

  The optimum softening state for perforating the resin sheet 50 is obtained based on the heat deformation temperature test (load deflection temperature test: JIS K7191-2 or ASTM D648, Vicat softening temperature test: JIS K7206) of the resin sheet 50. be able to. The heating temperature Tss of the stamper 30 and the supply temperature Tbf of the molten resin medium 55 are selected so that the obtained drilling temperature of the resin sheet 50 is maintained. The heating temperature Tss of the stamper 30 is preferably at least 10 ° C. and as low as possible from the melting point Tpm of the resin sheet 50 in order to prevent the resin sheet 50 from melting or being excessively softened. The supply temperature Tbf of the molten resin medium 55 is preferably higher than the thermal deformation temperature of the resin sheet 50. Note that which method is used in the thermal deformation test is determined in consideration of the type and characteristics of the resin sheet or molten resin medium used.

  A method for pressing the resin sheet 50 through the molten resin medium 55 is not particularly limited. However, as will be described in detail below, as shown in FIG. 1, the stamper 30 held in the lower mold 10, the resin sheet 50 mounted on the stamper 30 and the molten resin medium 55 are connected to the lower mold 10. It is preferable to press between the upper molds 20. Thereby, coupled with the viscoelastic characteristics of the molten resin medium 55, a large area can be pressed uniformly at high pressure.

  The fine through-hole forming method for the resin sheet described above can be preferably carried out by a press-type fine structure transfer molding apparatus schematically shown in FIG. As shown in FIG. 3A, the microstructure transfer molding apparatus includes a lower mold 10 having a temperature adjusting means, and an upper mold 20 having a temperature adjusting means that moves up and down to face the lower mold 10. A stamper 30 having fine protrusions 35 installed in the lower mold 10, a material supply device (not shown) for supplying a resin sheet 50 for forming a microstructured compact onto the stamper 30, and a resin sheet 50 And a medium supply device 40 (FIG. 3B) for supplying the molten resin medium 55 thereon.

  In this fine structure transfer molding apparatus, known ones can be used for the lower mold 10 and the upper mold 20, and the stamper 30 having the above-described configuration can be used. The medium supply device 40 is preferably a T-die type medium supply device having a T-die main body as shown in FIG. That is, the T-die body stores a molten resin medium having a required temperature in the resin reservoir, and can discharge the film-shaped molten resin medium from the lip portion having the T-die discharge port. Thereby, the molten resin medium 55 having a required thickness can be supplied (applied) onto the resin sheet 50.

  The material supply device is not particularly limited as long as it can supply the resin sheet 50 to a predetermined position on the stamper 30 as necessary. Note that this material supply device includes a peeling treatment that peels off the through-hole processed resin sheet attached to the upper mold 20 and peeled off from the stamper 30 and the solidified molten resin medium, which will be described below. Tools can be attached.

  The fine through-hole forming method for the resin sheet is performed as follows by the fine structure transfer molding apparatus. That is, as shown in FIG. 3, the method for forming a fine through-hole of the resin sheet includes a step (a) of supplying a resin sheet 50 onto a heated stamper 30 having fine protrusions, and a molten resin on the resin sheet 50. A step (b) of supplying the medium 55, a step (c) of pressing the softened resin sheet 50 through the molten resin medium 55 and perforating the resin sheet 50 by the fine protrusions 35, the molten resin medium 55 and the resin A step (c) in which the sheet 50 is cooled while being pressed, a step (d) in which the solidified molten resin medium 57 and the processed resin sheet 53 having undergone through-hole formation are peeled off from the stamper 30, and the processed resin sheet 53 And a step (f) of separating the solidified molten resin medium 57.

  In the above fine through hole forming method, an example in which fine through holes are drilled in the resin sheet 50 has been described. However, in addition to the fine protrusions 35, a fine structure having no through holes (ordinary fine structure) is provided on the stamper 30. Thus, a microstructure molded body in which a normal microstructure and through holes are formed in the resin sheet 50 can be manufactured. Further, since the resin sheet on which the fine structure is formed is easily damaged or distorted, the processed resin sheet 53 is removed from the stamper 30 together with the solidified molten resin medium 57 as shown in FIG. It is good to peel. Note that the processed resin sheet 53 and the solidified molten resin medium 57 peeled from the stamper 30 may be separated from the solidified molten resin medium 57 and the resin sheet 53 processed in the state shown in FIG. Well, after the resin sheet 53 and the solidified molten resin medium 57 processed in the state shown in FIG. 3E are once peeled from the upper mold 20, the processed resin sheet 53 and the solidified molten resin medium 57 are peeled off. (FIG. 3F) may be used.

  In order to supply the molten resin medium 55 onto the resin sheet 50, it is preferable to use a T-die type medium supply device 40 shown in FIG. 3 (b), whereby the thickness of the molten resin medium 55 is easily required. The thickness can be controlled. That is, the gap between the T die discharge port and the molten resin medium 55 already applied on the resin sheet 50 is set to several tens of μm to several tens mm, and the discharge speed of the molten resin discharged from the T die discharge port and By controlling the horizontal movement speed of the T-die discharge port, the thickness of the molten resin medium 55 applied on the resin sheet 50 can be controlled. In order to control the thickness of the molten resin medium 55 with high accuracy, it is preferable to reduce the gap. However, in consideration of the strength of the fine projections and the characteristics of the resin sheet 50 and the molten resin medium 55, it is possible to apply the molten resin medium 55 on the resin sheet 50 while ensuring a large gap as shown in FIG. it can.

  In the present fine through hole forming method, it has been explained that how to set the heating temperature of the stamper is important. For example, when the resin sheet 50 is PP (polypropylene) and the molten resin medium 55 is LDPE (low density polyethylene), the supply temperature Tbf of the molten resin medium 55 is the melting point Tpm (150 to 175 ° C.) of polypropylene, low Considering the melting point Tbm (98 to 115 ° C.) of the density polyethylene, the temperature is set to 130 ° C. The heating temperature Tss of the stamper 30 is 140 ° C.

  On the other hand, if the resin sheet 50 is a thermosetting epoxy resin and the molten resin medium 55 is PMMA (acrylic resin), the supply temperature Tbf of the molten resin medium 55 is 400 ° C. or higher because the epoxy resin has no melting point. Considering the fact that the epoxy resin has a decomposition temperature and the heat deformation temperature of the epoxy resin is 107 to 260 ° C, it is set to 260 ° C. The heating temperature Tss of the stamper 30 is set to 150 to 170 ° C. in consideration of the viscoelastic characteristics of the acrylic resin.

  Further, the cooling temperature of the stamper 30 when the punched resin sheet 53 is peeled off from the stamper 30 is also important. When the upper mold 20 and the lower mold 10 are opened by adjusting the cooling temperature of the stamper 30, the processed resin sheet 53 and the solidified molten resin medium 57 are integrated as shown in FIG. In this state, the processed resin sheet 53 can be peeled off from the stamper 30. As a result, it is possible to obtain a microstructure having no distortion or damage to the through-holes or the microstructure.

  The removal of the processed resin sheet 53 from the stamper 30 utilizes the fact that the adhesive force of the resin to the metal or the like shows a characteristic state depending on the temperature. That is, the perforated resin sheet 50 based on the adhesive force characteristics with the stamper 30 during the cooling of the processed resin sheet 53 and the adhesive force characteristics with the upper mold 20 during the cooling of the solidified molten resin medium 57. This is performed by setting the cooling temperature of the stamper 30 when the is peeled from the stamper 30.

  The cooling temperature of the stamper 30 is set as follows. For example, the case where the resin sheet and the molten resin medium have the characteristics shown in FIG. 5 will be described. In FIG. 5, the solid line indicates the characteristics (A and a) of the resin A used as the resin sheet 50, and the alternate long and short dash line indicates the characteristics (B and b) of the resin B used as the molten resin medium 55. The A or B curve shows the temperature change of the rigidity of each resin, the a curve shows the temperature change of the adhesion force with the stamper 30 of the resin A, and the b curve shows the temperature change of the adhesion force with the upper die 20 of the resin b. . In the figure, Tpm represents the melting point of Resin A, and Tbm represents the melting point of Resin B.

  As shown in FIG. 5, the adhesive force of Resin A or Resin B has a characteristic that it is remarkably high at a certain temperature but low before and after that temperature. The temperature Tse is a temperature at which the adhesive strength of the resin A is maximum, but at this temperature Tse, the adhesive strength of the resin I is low, and the rigidity of the resin A and B, which has been softened at a high temperature above the temperature Tse, is high. (Rigidity close to normal temperature of resin A and B). Therefore, if the mold is opened when the temperature of the stamper 30 is Tse, the processed resin sheet 53 adheres to the upper mold 20 integrally with the solidified molten resin medium 57 without causing damage or distortion. It can be safely peeled off from the stamper 30 in a state. The peeling temperature Tse of the resin sheet 53 is preferably 10 ° C. or less from the melting point Tbm of the resin (molten resin medium). That is, it is preferable that Tse ≦ Tbm−10. The temperature control of the stamper 30 is performed by the temperature control of the lower mold 10. Also, considering the resin adhesion characteristics, the lower mold 10 and the upper mold 20 are individually heated so that the solidified molten resin medium 57 and the processed resin sheet 53 adhere to the upper mold 20. Can be controlled.

  A test for molding fine through holes in a resin sheet was performed using the microstructure transfer molding apparatus shown in FIG. Test conditions are shown in Tables 1-2. Table 1 shows the types and characteristics of the tested resin sheets and the types and characteristics of the molten resin medium. Table 2 shows test conditions such as the thickness of the resin sheet or the molten resin medium applied thereto, the pressing force, the heating temperature of the stamper, and the shape of the fine protrusions. FIG. 6A shows the shape of the fine protrusions of the stamper used in this test.

  The resin sheets tested were polypropylene (PP), polycarbonate (PC), cyclic polyolefin (COP), and polyethylene naphthalate (PEN) resin sheets. The molten resin media tested was a low density polyethylene (LDPE), polypropylene (PP), high impact polystyrene (HIPS) molten resin.

  The test results are shown in Table 3. The drilling dimensions shown in Table 3 indicate the dimensions of the through holes when the processed resin sheet is peeled off from the solidified molten resin medium to be in a product state (FIG. 6B). Comparing the shape of the fine protrusions shown in Table 2 with the drilling dimensions shown in Table 3, it can be seen that according to the present invention, fine through holes can be formed with high accuracy. Further, as shown in Table 2, it can be seen that the pressing force in the present invention may be a low pressure of about 10 MPa or less.

10 Lower mold
20 Upper mold
30 Stamper
35 fine protrusions
40 Media feeder
50 resin sheet
53 Processed resin sheet
55 Molten resin media
57 Solidified molten resin media

Claims (13)

Supplying a resin sheet onto a heated stamper having fine protrusions;
Supplying a molten resin medium onto the resin sheet;
Pressing the softened resin sheet through the molten resin medium, and perforating the resin sheet with the fine protrusions;
Cooling the molten resin medium and the resin sheet while pressing;
Peeling the solidified molten resin medium and the processed resin sheet from the stamper;
Peeling the processed resin sheet and the solidified molten resin medium. A method for forming a fine through-hole of a resin sheet.   2. The fine resin sheet according to claim 1, wherein when the resin sheet is a thermoplastic resin, the molten resin medium has a melting point Tbm that satisfies Tbm ≦ Tpm with respect to a melting point Tpm of the resin sheet. Through-hole forming method.   3. The resin sheet fine according to claim 2, wherein when the resin sheet is a thermoplastic resin, a temperature Tbf for supplying the molten resin medium onto the resin sheet satisfies Tbm <Tbf ≦ Tpm. Through-hole forming method.   The resin sheet according to any one of claims 1 to 3, wherein the solidified molten resin medium and the processed resin sheet are separated from the stamper by adjusting a temperature of the stamper. Fine through hole forming method.   The temperature adjustment of the stamper is performed by the adhesive force characteristic between the resin sheet and the stamper with respect to the temperature of the stamper, the molten resin medium with respect to the temperature of the molten resin medium, and a pressing member used to press the molten resin medium. The method for forming a fine through-hole of a resin sheet according to claim 4, wherein the method is performed on the basis of adhesive strength characteristics.   The method for forming fine through holes in a resin sheet according to claim 4, wherein a peeling temperature Tse at which the solidified molten resin medium and the processed resin sheet are peeled from the stamper is Tse ≦ Tbm-10. .   The method for forming fine through holes in a resin sheet according to any one of claims 1 to 6, wherein the molten resin medium is supplied by applying a molten resin medium discharged from a T die.   The fine protrusion has a cone, a pyramid, a cylinder, a cylinder having a hemispherical tip, a cylinder having a conical tip, or a cone or a pyramid having a pyramid tip, and has a height of 1 μm to 3 mm. The method for forming a fine through-hole of a resin sheet according to any one of claims 1 to 7, wherein an average diameter of the cross section is φ1 μm to φ1 mm.   The resin sheet has a thickness of 1 μm to 1 mm, the molten resin medium has a thickness of 50 μm to 3 mm, and the fine protrusion has a height that exceeds the thickness of the resin sheet and the thickness of the resin sheet and the molten resin medium. The method for forming a fine through-hole of a resin sheet according to any one of claims 1 to 8, wherein the method is less than the sum.   The material of the molten resin medium is methacrylic resin, polycarbonate resin, polystyrene resin, cyclic polyolefin resin, polyethylene terephthalate resin, polyethylene naphthalate resin / polylactic acid resin, polyethylene resin, polypropylene resin, thermoplastic elastomer resin, methacrylic butadiene, The method for forming a fine through-hole of a resin sheet according to any one of claims 1 to 9, which is a styrene copolymer, an acrylic / butadiene / styrene copolymer, or a polyoxymethylene resin.   The resin sheet is made of polytetrafluoroethylene (PTFE) resin, polyamide resin, polyimide resin, polyamide-imide resin, epoxy resin, unsaturated polyester resin, glass fiber reinforced resin (GFRP), carbon fiber reinforced resin (CFRP). , Methacrylic resin, polycarbonate resin, polystyrene resin, cyclic polyolefin resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polylactic acid resin, polyethylene resin, polypropylene resin, thermoplastic elastomer resin, methacrylic butadiene styrene copolymer, acrylic It is a butadiene styrene copolymer or a polyoxymethylene resin, The fine through-hole shaping | molding method of the resin sheet in any one of Claims 1-10 characterized by the above-mentioned. A press-type microstructure transfer molding apparatus for manufacturing a microstructure molded body having a through-hole,
A lower mold having a temperature adjusting means;
An upper mold that moves up and down to face the lower mold and has temperature adjusting means;
A stamper having fine protrusions installed on the lower mold,
A material supply device for supplying a resin sheet for forming the microstructured compact onto the stamper;
A microstructure transfer molding apparatus comprising: a medium supply device that supplies a molten resin medium onto the resin sheet.   The medium supply device includes a thickness adjusting unit that adjusts so that a molten resin medium supplied onto the resin sheet is supplied to a predetermined thickness with respect to a thickness of the resin sheet. The fine structure transfer molding apparatus according to claim 12.

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