JP2013094886A - Method of manufacturing micro through-hole formed product, and mist formation filter manufactured by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a micro through-hole formed product capable of precisely forming many micro through-holes on a base sheet of synthetic resin.SOLUTION: A micro through-hole formed product 40 is manufactured by using a micro through-hole forming device 10 equipped with a supporting base 11, a back sheet 12 for supporting a base sheet 20, and an ultrasonic form block 30 having many projections 31. First, the ultrasonic form block 30 is position-controlled and lowered until the projection 31 comes directly above the base sheet 20. Then, the control of the ultrasonic form block 30 is switched from position control to load control to further lower the ultrasonic form block 30, the projection 31 of the ultrasonic form block 30 is made to ultrasonic-vibrate so that the projection 31 penetrates the base sheet, and thereby many micro though-holes 41 are formed on the base sheet 20.

Description

  The present invention relates to a method for producing a fine through-hole molded product that produces a fine through-hole molded product having a large number of fine through-holes by forming a large number of fine through-holes in a base sheet using a fine through-hole molding device. And a mist-forming filter manufactured by such a method of manufacturing a fine through-hole molded product.

  Conventionally, many fine through holes are formed in a metal sheet. In this case, it is common to first pattern a predetermined pattern on a metal sheet by photolithography, and then perform chemical etching or dry etching on this to form a large number of through holes. There is also a method of making a through hole with a laser beam, an electron beam, or a neutron beam.

  However, when such a method is used, it is difficult to freely set the shape of the fine through-hole according to the functional application due to processing restrictions. Moreover, the sheet | seat used as object is restricted to glass, a semiconductor, a metal. Furthermore, since there are many processes for forming a through-hole, it is necessary to use many manufacturing apparatuses (for example, Unexamined-Japanese-Patent No. 5-28912).

  On the other hand, when a large number of fine (for example, diameter of 100 μm or less) through-holes are to be formed in a synthetic resin sheet, a nanoimprint technique (a technique for transferring fine irregularities formed on a mold onto a resin material) is used. It can also be used. However, when the nanoimprint technique is used, fine unevenness can be formed on the surface of the resin material, but a through-hole penetrating the resin material cannot be formed.

  Moreover, when forming many fine through-holes in a synthetic resin sheet, it is also conceivable to use an injection molding method. However, in this case, the molten resin does not flow well in the mold, and fine through holes cannot be formed. Furthermore, even if the compression molding method is used, it is not possible to form fine through holes in the same manner. As described above, it is not easy to form a large number of fine through holes in a synthetic resin sheet.

  By the way, this applicant forms many fine through-holes in the base material sheet | seat which consists of a synthetic resin using the ultrasonic shaping | molding die which has a protruding part which ultrasonically vibrates in Unexamined-Japanese-Patent No. 2010-137313. Has proposed.

Japanese Patent Laid-Open No. 5-28912 JP 2010-137313 A

  The fine through-hole forming apparatus proposed in Japanese Patent Application Laid-Open No. 2010-137313 makes the ultrasonic vibration vibrate contact with a base material sheet made of a synthetic resin, thereby converting the energy of ultrasonic vibration into thermal energy. The base sheet is melted locally, and the shape of the protruding portion is formed on the base sheet, thereby forming a large number of fine through holes in the base sheet. In such a fine through-hole forming apparatus, it is required to further improve the accuracy of the through-hole.

  The present invention has been made in consideration of such points, and a method for producing a fine through-hole molded product capable of forming a large number of fine through-holes in a synthetic resin base sheet with high accuracy, and It aims at providing the filter for mist formation produced using such a method.

  A method for manufacturing a fine through-hole molded product according to an embodiment of the present invention includes a cradle, a back sheet that is held on the cradle, has heat resistance, and supports a base sheet made of synthetic resin, and a back sheet The ultrasonic molding die is arranged in the upper part and has a number of protruding parts in the lower part, and the ultrasonic molding die can move in the vertical direction and vibrates ultrasonically in the vertical direction to vibrate the base sheet. In the method of manufacturing a fine through-hole molded product using a fine through-hole molding apparatus that heats and melts the base sheet to form a large number of fine through-holes in the base sheet, The process of lowering the ultrasonic mold until the position is directly above, and switching the control of the ultrasonic mold from position control to load control, further lowering the ultrasonic mold, The ridge is ultrasonically vibrated, and the ridge is By penetrating the wood sheet, it is characterized in that it comprises a step of forming a plurality of fine through-holes in the substrate sheet, a.

  In the method for manufacturing a fine through-hole molded product according to an embodiment of the present invention, the step of forming a large number of fine through-holes in the base sheet is performed after the protrusion comes into contact with the base sheet. You may have the penetration process which raises the amplitude which ultrasonically vibrates a protruding part in the meantime, increasing the applied load to a holding load in steps.

  In the method for manufacturing a fine through-hole molded article according to an embodiment of the present invention, after the penetration step, the descent of the ultrasonic mold is stopped and the ultrasonic vibration of the protrusion is stopped, and the load is held in this state. There may be provided a holding step for holding the load for a certain period of time.

  In the method for manufacturing a fine through-hole molded product according to an embodiment of the present invention, the fact that the projecting portion has contacted the base sheet may be determined by the fact that the load applied to the projecting portion has reached the contact load. Good.

  In the method for manufacturing a fine through-hole molded article according to an embodiment of the present invention, after the holding step, the protruding portion may be ultrasonically vibrated again while keeping the load applied to the protruding portion at the holding load.

  In the method for manufacturing a fine through-hole molded article according to an embodiment of the present invention, after the holding step, the ultrasonic mold may be raised and the protruding portion may be ultrasonically vibrated again.

  In the method for manufacturing a fine through-hole molded article according to one embodiment of the present invention, after the step of forming a large number of fine through-holes in the base sheet, the ultrasonic mold is raised to remove the protruding portion from the base sheet. You may further provide the process of extracting.

  Moreover, the fine through-hole molded article by one embodiment of this invention is obtained by the manufacturing method of the said fine through-hole molded article.

  Furthermore, the filter for mist formation according to an embodiment of the present invention is a filter for mist formation in which a large number of fine through holes are formed in a base sheet made of synthetic resin, and the mist formation filter is the fine filter described above. It was obtained by the manufacturing method of a through-hole molded product, the diameter of a through-hole is different in the front and back of a base material sheet, the diameter of one surface is 1-10 micrometers, and the diameter of the other surface is 20 It is ˜80 μm.

In the filter for mist formation according to one embodiment of the present invention, the number of through holes may be 200 to 1000 / mm ² .

  In the mist forming filter according to one embodiment of the present invention, the through hole may have a conical shape with a widening end.

  A mist generator according to an embodiment of the present invention is a mist generator that oscillates an ultrasonic transducer to mist a liquid, and the mist generator is disposed between the ultrasonic transducer and a mist generating port. A forming filter is provided.

  In the mist generating apparatus according to the embodiment of the present invention, the mist forming filter may be arranged such that the side with the larger diameter of the fine through hole is the ultrasonic transducer side.

  According to the method for manufacturing a fine through-hole molded product of the present invention, the position of the ultrasonic molding die is lowered by controlling the position of the ultrasonic molding die until the protruding portion is directly above the base sheet, and the control of the ultrasonic molding die is loaded from the position control. By switching to the control, the ultrasonic mold is further lowered, and the ultrasonic mold is brought into contact with the ultrasonic vibration so as to penetrate the base sheet. As described above, when the ultrasonic molding die is subjected to load control and the protruding portion penetrates the base sheet, a large number of fine through holes can be formed in the base sheet with high accuracy.

The schematic front view which shows the fine through-hole shaping | molding apparatus by one embodiment of this invention. The front view which shows the ultrasonic shaping | molding die of the fine through-hole shaping | molding apparatus by one embodiment of this invention. The bottom view which shows the ultrasonic shaping | molding die of the fine through-hole shaping | molding apparatus by one embodiment of this invention (III direction arrow line view of FIG. 2). FIG. 4 is a vertical sectional view (sectional view taken along line IV-IV in FIG. 3) showing an ultrasonic forming die of the fine through-hole forming apparatus according to the embodiment of the present invention. The schematic perspective view which shows the method of producing the ultrasonic shaping | molding die of the fine through-hole shaping | molding apparatus by one embodiment of this invention. The schematic sectional drawing which shows the method of producing the ultrasonic shaping | molding die of the fine through-hole shaping | molding apparatus by one embodiment of this invention. Schematic which shows the manufacturing method of the fine through-hole molded article by one embodiment of this invention. The expanded schematic sectional drawing which shows the manufacturing method of the fine through-hole molded article by one embodiment of this invention. The graph which shows the change of the amplitude and position of the protrusion part of an ultrasonic shaping | molding die, and the load added to a protrusion part in the manufacturing method of the fine through-hole molded article by one embodiment of this invention. The top view which shows the fine through-hole molded article by one embodiment of this invention. The vertical sectional view which shows the fine through-hole molded article by one embodiment of the present invention (the XI-XI line sectional view of Drawing 10). The expanded schematic sectional drawing which expanded a part of mist generator by one embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 12 show an embodiment of the present invention.

<Micro through-hole forming device>
First, the overall configuration of a fine through-hole forming apparatus for forming a fine through-hole molded product will be described with reference to FIG.

  As shown in FIG. 1, a fine through-hole forming apparatus 10 includes a fixed cradle 11 and a back sheet 12 that is held on the cradle 11 and has a heat resistance and supports a base sheet 20 made of synthetic resin. And.

  The upper surface of the cradle 11 can be heated to a desired temperature by the temperature control device 16, and the base sheet 20 can be heated via the back sheet 12 described later.

  The back sheet 12 preferably has heat resistance (melting temperature is 250 ° C. or higher) and vibration absorption to absorb vibration by elastic deformation and spring back to generate contact pressure against the penetration pressure. . Further, the back sheet 12 is preferably excellent in peelability with respect to the base sheet 20. For example, in the present embodiment, a backsheet release layer 12 a having peelability with respect to the base sheet 20 is formed on the upper surface of the backsheet 12. As such a back sheet 12, for example, a sheet of polyimide, polytetrafluoroethylene (PTFE), a heat-resistant plastic sheet having a fluorine-coated layer or a silicon resin-coated layer (back sheet peeling layer) 12a, or the like, or A combination of these layers can be used.

  On the other hand, the base sheet 20 is made of a heat-melting plastic having a property of being melted by ultrasonic waves, but preferably has a certain degree of rigidity and heat resistance. In this case, the melting temperature of the base sheet 20 is preferably lower by 50 ° C. or more than the melting temperature of the back sheet 12. This is because if the melting temperature of the base sheet 20 and the melting temperature of the back sheet 12 are close, the back sheet 12 is thermally deformed when the base sheet 20 is formed. Examples of the material of the base sheet 20 include polycarbonate (PC), amorphous polyethylene terephthalate (A-PET), crystalline polyethylene terephthalate, stretchable polyethylene terephthalate, methacrylate polymer (PMMA), polystyrene ( PS), ABS, etc. can be used. In addition, polysulfone (PSU), polyethersulfone (PES), polyetheretherketone (PEEK), polyamideimide (PAI), polyetherimide (PEI), thermoplastic polyimide (TPI), polymethylpentene (PMP), super High molecular weight polyethylene (UHMWPE), liquid crystal polymer (LCP), polyarylate (PAR), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyacetal (POM), Thermoplastics such as polyamide (PA), polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) can also be applied. In addition, although the thickness of the base material sheet 20 is arbitrary, it is preferable to set it as about 10 micrometers-10 mm in view of the vibration width of the ultrasonic molding die 30 mentioned later and the positional accuracy of the ultrasonic molding die 30 in the vertical direction.

  Further, as shown in FIG. 1, the fine through-hole forming apparatus is provided with a suction portion 13 that penetrates through the back sheet 12. The substrate sheet 20 can be fixed and held on the back sheet 12 by vacuum suction through the suction unit 13.

  Further, an ultrasonic molding die 30 made of an ultrasonic horn mold is disposed above the back sheet 12. The ultrasonic mold 30 includes a base portion 33 and a horn head 32 that is attached to the base portion 33 and has a large number of protruding portions 31 formed in the lower portion thereof. Further, the heating device 14 is connected to the ultrasonic molding die 30, and a large number of the protruding portions 31 of the ultrasonic molding die 30 can be supplementarily heated by the heating device 14. In addition to heating by ultrasonic vibration of the ultrasonic mold 30, the protrusion 31 of the ultrasonic mold 30 can be efficiently heated by using such a heating device 14 as an auxiliary.

  Further, the mold control device 15 is connected to the ultrasonic mold 30. The ultrasonic mold 30 is controlled by the mold control device 15 and moves up and down in the vertical direction and ultrasonically vibrates in the vertical direction. It is preferable that the raising / lowering position accuracy of the ultrasonic molding die 30 and the amplitude accuracy of ultrasonic vibration by the molding die control device 15 are both on the order of 1 μm.

  The ultrasonic mold 30 is controlled by the mold control device 15, and the protruding portion 31 provided at the tip of the ultrasonic mold 30 descends while ultrasonically vibrating in the vertical direction, and comes into contact with the base sheet 20 to contact the base sheet 20. Is heated by vibration. It takes time to soften or melt the base sheet 20 only by this vibration heating and mold the base sheet 20 by the ultrasonic forming die 30. When the energy of the ultrasonic vibration is increased, the vibration amplitude is also increased, so that the position accuracy of the through hole to be formed is lowered. In the present invention, as described above, since the cradle 11 is heated and the base sheet 20 can be heated to near the glass transition temperature or the softening temperature, ultrasonic vibration energy capable of maintaining positional accuracy is provided. The base sheet 20 can be easily molded (that is, the base sheet 20 is softened or melted). As a result, a large number of fine through-holes can be easily formed in the synthetic resin base material sheet 20 in a simple and short time.

  The cradle 11 is temperature-controlled so that the temperature of the base sheet 20 is close to the glass transition temperature or the softening temperature, but is preferably controlled to be a little lower than the softening temperature of the synthetic resin. When the temperature of the base material sheet 20 becomes a temperature equal to or higher than the softening temperature of the synthetic resin, the entire heated portion of the base material sheet 20 starts to soften. If the portion other than the portion with which the protruding portion 31 of the ultrasonic forming die 30 of the base sheet 20 abuts is softened, a highly accurate through hole may not be formed. The temperature of the base material sheet 20 is suitably 1 to 50 ° C., more preferably about 5 to 30 ° C. lower than the softening temperature.

  In FIG. 1, the ultrasonic mold 30 is lowered by the mold control device 15, the protruding portion 31 that vibrates ultrasonically is brought into contact with the base sheet 20, and the base sheet 20 is vibrated and heated. Thereby, the base material sheet 20 of the part which the protruding part 31 contacted is softened or melted. When the base sheet 20 is softened or melted, the ultrasonic mold 30 is further lowered by the mold control device 15 to bring the protruding portion 31 of the ultrasonic forming mold 30 into contact with the base sheet 20. The base material sheet 20 is vibrated and heated by ultrasonically vibrating 31, and the protruding portion 31 provided at the tip of the ultrasonic forming die 30 penetrates the base material sheet 20. When the tip of the projecting portion 31 reaches the back sheet 12, the molding die control device 15 stops the ultrasonic vibration of the ultrasonic molding die 30 and also stops the heating due to the addition of vibration energy. It shifts to cooling by heat conduction from the upper and lower surfaces. On the upper surface of the base material sheet 20, the base material sheet 20 is cooled by the protruding portions 31 whose temperature is adjusted to a glass transition point or a softening temperature or lower. On the other hand, the lower surface of the base sheet 20 is cooled by the temperature control device 16 to cool the base sheet 20 or the temperature of the base 11 is changed to a glass transition of the synthetic resin by the temperature control device 16. The base sheet 20 is cooled to a desired temperature by heat conduction from the base sheet 20 to the cradle 11.

  After the synthetic resin of the portion of the base sheet 20 cooled as described above is in contact with the ultrasonic forming die 30 (the portion where the protruding portion 31 penetrates) is solidified, the forming die control device 15 Then, the ultrasonic forming die 30 is moved upward to extract the protruding portion 31. At this time, the protruding portion 31 may not peel from the through hole formed in the base sheet 20, and the lower end of the horn head 32 of the ultrasonic forming die 30 as the ultrasonic forming die 30 moves upward. The base material sheet 20 may also be lifted upward together with the protruding portions 31 in the above, and the fine through holes may be deformed. In the present invention, the protruding portion 31 can be easily extracted by slightly raising the ultrasonic forming die 30 and again performing ultrasonic vibration. As a result, a more accurate through hole can be formed in the base sheet. In addition, the detail of the effect | action at the time of forming a through-hole in the base material sheet 20 using the shaping | molding die control apparatus 15 as mentioned above is mentioned later.

<Ultrasonic mold>
Next, the configuration of the above-described ultrasonic molding die 30 will be further described with reference to FIGS.

  As shown in FIG. 2, the ultrasonic mold 30 includes a base portion 33 having a tapered shape from the upper side to the lower side, and a horn head 32 screwed to the lower end of the base portion 33 by a screw portion 32b. Have. Of these, a cylindrical tip convex portion 32 a is formed at the lower end of the horn head 32. Further, a large number of projecting portions 31 are provided so as to project downward from the tip convex portion 32a. The horn head 32 is made of a metal such as titanium, aluminum, steel, and stainless steel. Further, the projecting portion 31 can be constituted by a Ni plating layer or a Cr plating layer provided on these metals. The base portion 33 has a circular horizontal cross section whose diameter gradually decreases from the top to the bottom.

  next. The configuration of the protruding portion 31 of the ultrasonic mold 30 will be further described with reference to FIGS. As shown in FIGS. 3 and 4, a large number of protrusions 31 having the same shape are formed on the tip protrusion 32 a of the horn head 32. Each protrusion 31 has a mountain shape. That is, each protrusion 31 has a planar circular top 31a and a skirt 31b extending from the top 31a to the periphery. Among these, the skirt part 31b has a circular horizontal cross section whose diameter gradually increases from the top part 31a side toward the tip convex part 32a side of the horn head 32. In order to set the amplitude of the ultrasonic mold 30 small, the diameter may be gradually decreased from the upper side to the lower side in accordance with the ultrasonic transducer, or the diameter may be the same. Also good. Furthermore, a valley portion 31c is formed between adjacent top portions 31a. Each protruding portion 31 may have any shape having a taper, but it is particularly preferable to form the tip of each protruding portion 31 at an acute angle. By making the tip of each protrusion 31 have an acute angle, the area of the part that first contacts the base sheet 20 can be reduced during molding. Thus, vibration energy can be easily transmitted to the base sheet 20 and melting of the base sheet 20 can be easily started.

In FIG. 4, the diameter d ₁ of the top portion 31 a of each protrusion 31 can be arbitrarily determined depending on the shape of the fine through-hole molded product 40, but is preferably about 1 μm to 10 μm, for example. Distance L ₁ between the top 31a Adjacent, can be arbitrarily determined similarly by the shape of the fine through-hole molded article 40, for example, it is preferably about 20 m to 100 m. Similarly, the height h ₁ of each protrusion 31 can be arbitrarily determined, but is preferably about 10 μm to 100 μm, for example.

  Next, a method for producing such an ultrasonic mold 30, particularly a method for forming a plurality of protruding portions 31 of the ultrasonic mold 30 will be described with reference to FIGS. 5 and 6.

  First, a raw horn head 32 made of titanium or the like is prepared. Next, the unprocessed horn head 32 is mounted on the ultraprecision cutting machine 36. Here, as shown in FIGS. 4 and 5, the ultraprecision cutting machine 36 has a cutting tool 37 having a diamond cutting edge 38 provided at the tip. As such an ultra-precise cutting machine 36, a machine having a control accuracy of about 1 nm and capable of setting the surface roughness Ra of the die after processing to several nm is preferable. Specifically, as the ultra-precision cutting machine 36, for example, an ultra-precision nano-machining machine (ROBONANO) manufactured by FANUC CORPORATION can be exemplified.

Then, the cutting tool 37 of the ultra-precision cutting machine 36 abuts the leading protrusion 32a of the horn head 32 while rotating (rotation) in a clockwise direction about the axis A _1. Subsequently, the cutting tool 37 rotates (revolves) clockwise around the portion that becomes the top portion 31a of each protruding portion 31 in the tip convex portion 32a of the horn head 32, while the tip convex portion 32a of the horn head 32. Cutting. As a result, a chevron-shaped projecting portion 31 having a top portion 31a and a skirt portion 31b is formed on the tip convex portion 32a of the horn head 32. Thereafter, by repeating such an operation as many as the number of the projecting portions 31, a large number of projecting portions 31 are formed on the tip convex portion 32 a of the horn head 32.

<Method for producing fine through-hole molded product>
Next, with reference to FIGS. 7A to 7F, FIGS. 8A to 8D, and FIG. 9, a fine through-hole molded product 40 is manufactured using the fine through-hole forming apparatus 10 described above. A method will be described.

  First, based on the three-dimensional shape data of the fine through-hole molded product 40 to be manufactured, the horn head 32 is cut using the ultra-precision cutting machine 36, and the ultrasonic mold 30 is manufactured by the method described above. To do.

  Subsequently, the ultrasonic molding die 30 is mounted on the fine through-hole molding device 10, and the ultrasonic molding die 30 is moved from the normal room temperature (20 ° C.) by the heating device 14 to the synthetic resin glass. Heating is performed at a temperature in the vicinity of the transition temperature or the softening temperature and low enough to cool and solidify the base sheet 20 after molding.

  Next, the back sheet 12 is held on the cradle 11, and the base sheet 20 is placed on the back sheet 12. Further, the base sheet 20 is fixed and supported so as not to move on the back sheet 12 by vacuum suction by the suction unit 13.

  Subsequently, the cradle 11 is heated by the temperature control device 16 to heat the base sheet 20 to near the glass transition temperature or softening temperature of the synthetic resin.

At this time, the ultrasonic forming die 30 is disposed above the back sheet 12, and the protruding portion 31 is in the initial position (Z ₀ ) (FIGS. 7A and 9). At this time, the protruding portion 31 of the ultrasonic mold 30 is not yet ultrasonically vibrated (amplitude = 0), and no load is applied to the protruding portion 31 (load = 0).

Next, the ultrasonic mold 30 is lowered toward the base sheet 20 by the mold control device 15 until the protruding portion 31 reaches the switching position (Z ₁ ) immediately above the base sheet 20. While the protruding portion 31 moves from the initial position (Z ₀ ) to the switching position (Z ₁ ), the position of the ultrasonic forming die 30 is controlled by the forming die control device 15, and the protruding portion 31 is lowered at a constant speed. Is done.

Thereafter, the protruding portion 31 of the ultrasonic mold 30 reaches the switching position (Z ₁ ) immediately above the base sheet 20 (FIGS. 8A and 9). At this time, the mold control device 15 switches the control of the ultrasonic mold 30 from position control to load control. At the same time, the mold control device 15 ultrasonically vibrates the protrusion 31 in the vertical direction with the first amplitude (A ₁ ) (FIG. 9), and further lowers the ultrasonic mold 30. As this 1st amplitude (A1), it is good also as ₁ micrometer-10 micrometers, for example. Moreover, although the frequency of the protrusion 31 can be set arbitrarily, it is preferable to set it to about 20 kHz to 40 kHz. At this time, no load is applied to the protruding portion 31 (load = 0).

When the ultrasonic molding die 30 is lowered, the protruding portion 31 comes into contact with the base sheet 20 and reaches the contact position (Z ₂ ) (FIGS. 7B, 8B, and 9). The contact of the protruding portion 31 with the base material sheet 20 is determined by the mold control device 15 detecting that the load applied to the protruding portion 31 has reached a predetermined contact load (P ₀ ). . The contact load (P ₀ ) can be set to a load slightly exceeding 0, for example, 1N to 3N. At this time, the amplitude of the protruding portion 31 is maintained at the first amplitude (A ₁ ) (FIG. 9).

  When the projecting portion 31 comes into contact with the base material sheet 20, the portion of the base material sheet 20 where the projecting portion 31 comes into contact is vibrated and heated by vibration energy of ultrasonic vibration. The synthetic resin constituting the base sheet 20 reaches the softening or melting temperature due to the vibration heating by the vibration energy and the heat energy applied from the cradle 11, and as a result, the protruding portion 31 of the base sheet 20 Only the abutting part is locally softened or melted.

Subsequently, the ultrasonic mold 30 is further lowered. During this time, the protruding portion 31 penetrates through the base sheet 20 while heating the base sheet 20 by ultrasonic vibration. During this time, the control of the ultrasonic molding die 30 is continuously maintained at the load control, and while the load applied to the projecting portion 31 is increased step by step up to the holding load (P ₂ ), the projecting portion 31 is superposed during this time. The amplitude of sonic vibration is increased step by step.

Specifically, after the projecting portion 31 comes into contact with the base material sheet 20, first, the set load applied to the projecting portion 31 is changed to the first load (P ₁ ), and the amplitude of the projecting portion 31 is the first. The amplitude (A ₁ ) is maintained (FIG. 9). As the protruding portion 31 penetrates into the base sheet 20, the load applied to the protruding portion 31 increases and increases from the contact load (P ₀ ) to the first load (P ₁ ). When the load applied to the protruding portion 31 becomes the first load (P ₁ ), the protruding portion 31 reaches the intermediate position (Z ₃ ) (FIGS. 8C and 9). As the first load (P _1), can be set to, for example, 40N～70N. In FIG. 9, the set load is indicated by a one-dot chain line, and the actually measured load is indicated by a solid line.

In this way, after the protrusion 31 contacts the base sheet 20 at the contact position (Z ₂ ), the load applied to the protrusion 31 increases to the first load (P ₁ ). The process until the shape part 31 reaches the intermediate position (Z ₃ ) corresponds to the first step.

Thus, when the protrusion 31 reaches the intermediate position (Z ₃ ), the mold control device 15 changes the set load applied to the protrusion 31 to the second load (P ₂ ). Further, the amplitude of the protrusion 31 is changed from the first amplitude (A ₁ ) to the second amplitude (A ₂ ), and the protrusion 31 is ultrasonically vibrated with the second amplitude (A ₂ ) (FIG. 9). The second amplitude (A ₂ ) is larger than the first amplitude (A ₁ ), and may be, for example, 5 μm to 20 μm.

Subsequently, the ultrasonic molding die 30 is further lowered to increase the load applied to the protruding portion 31 from the first load (P ₁ ) to the second load (P ₂ ), while having a second amplitude (A ₂ ). The protrusion 31 is ultrasonically vibrated. In this state, the protrusion 31 is ultrasonically vibrated, the base sheet 20 is vibrated and heated, and the base sheet 20 penetrates through the protrusion 31. In this way, the tip of the protruding portion 31 of the ultrasonic forming die 30 comes into contact with the back sheet 12 (back sheet release layer 12a). The contact of the protruding portion 31 with the back sheet 12 is determined by the mold control device 15 detecting that the load applied to the protruding portion 31 has reached the second load (P ₂ ). The second load (P ₂ ) is larger than the first load (P ₁ ), and can be set to, for example, 80N to 120N. Thus, when the tip of the protruding portion 31 abuts on the back sheet 12 and the load applied to the protruding portion 31 becomes the second load (P ₂ ), the protruding portion 31 reaches the lower end position (Z ₄ ). (FIG. 7 (c), FIG. 8 (d), FIG. 9).

In this way, the load applied to the protruding portion 31 is increased from the first load (P ₁ ) to the second load (P ₂ ), and the protruding portion 31 is moved from the intermediate position (Z ₃ ) to the lower end position (Z The process up to ₄ ) corresponds to the second step. Furthermore, the first step and the second step described above correspond to the penetration step in the present embodiment.

  When the tip of the protruding portion 31 comes into contact with the back sheet 12, the lowering of the ultrasonic forming die 30 is stopped. At the same time, the amplitude of the ultrasonic vibration of the ultrasonic forming die 30 is gradually attenuated and finally stopped while maintaining the vibration lower end at the tip of the protruding portion 31 on the surface of the back sheet 12. .

Thereafter, in this state, the ultrasonic molding die 30 is pressed and held for a predetermined time while keeping the load at the second load (P ₂ ) (FIG. 9). In this case, the second load (P ₂ ) corresponds to the holding load. During this time, the heating device 14 is stopped, the ultrasonic mold 30 is cooled, and at the same time, the temperature control device 16 lowers the temperature of the cradle 11 until the base sheet 20 reaches a temperature equal to or lower than the glass temperature or the softening temperature of the synthetic resin. Cooling. Alternatively, at the same time as the vibration is stopped, the base sheet 20 is cooled and cured at the temperature of the ultrasonic molding die 30 and the cradle 11 that have been preset in temperature. Through these steps, the base sheet 20 that has been locally softened or melted is solidified, and a large number of fine through holes 41 are formed in the base sheet 20, and the base sheet 20 has a large number of fine through holes 41. A fine through-hole molded product 40 is molded. In this case, the ultrasonic mold 30 and the base sheet 20 may be actively cooled by using a cooling device (not shown).

In this way, the lowering of the ultrasonic molding die 30 and the ultrasonic vibration of the protruding portion 31 are stopped, and the ultrasonic wave is maintained while maintaining the load at the second load (P ₂ ) (holding load) in this state. The process of holding the molding die 30 at the lower end position (Z ₄ ) for a predetermined time and cooling the base sheet 20 (the fine through-hole molded product 40) corresponds to the holding process.

  Next, the ultrasonic mold 30 is raised by the mold control device 15. In this case, the ultrasonic mold 30 and the fine through-hole molded product 40 (base material sheet 20) are cooled and the dimensions are slightly reduced. In this state, the fine through-hole molded product 40 can be released from the ultrasonic molding die 30 (FIG. 7D). Further, when the fine through-hole molded product 40 (base sheet 20) adheres to the ultrasonic mold 30, the ultrasonic mold 30 is first raised slightly, and then the ultra short time ultrasonic mold 30 is again formed. By vibrating, the fine through-hole molded product 40 can be easily released from the ultrasonic mold 30.

Alternatively, the ultrasonic molding die 30 is vibrated again for a very short time while keeping the load applied to the protruding portion 31 at the second load (P ₂ ), so that the diameter of the fine through hole 41 and the like can be reduced. The shaping state may be changed slightly.

  Subsequently, the vacuum suction by the suction unit 13 is stopped, and the back sheet 12 and the fine through-hole molded product 40 are removed from the cradle 11 (FIG. 7E). Finally, the fine through-hole molded product 40 is obtained by peeling the fine through-hole molded product 40 from the back sheet 12 (FIG. 7F). The fine through-hole molded product 40 may be peeled directly from the back sheet 12 held on the cradle 11.

As described above, according to the present embodiment, the ultrasonic molding die 30 is controlled to be lowered until the protruding portion 31 reaches the switching position (Z ₁ ) immediately above the base sheet 20, and then the switching position. At (Z ₁ ), the control of the ultrasonic mold 30 is switched from position control to load control, and the ultrasonic mold 30 is further lowered. At this time, the protrusion 31 is ultrasonically vibrated, and the protrusion 31 penetrates the base sheet 20, thereby forming a large number of fine through holes 41 in the base sheet 20. As described above, when the ultrasonic molding die 30 is subjected to load control and the protruding portion 31 penetrates the base sheet 20, a large number of fine through holes 41 can be formed in the base sheet 20 with high accuracy.

In addition, according to the present embodiment, when the large number of fine through holes 41 are formed in the base sheet 20, the protruding portion 31 comes into contact with the base sheet 20 at the contact position (Z ₂ ). While increasing the load applied to the protrusion 31 to the first load (P ₁ ), the protrusion 31 is ultrasonically vibrated with the first amplitude (A ₁ ) during this time (first step). Thereafter, while increasing the load applied to the protruding portion 31 from the first load (P ₁ ) to the second load (P ₂ ), the protruding portion has a second amplitude (A ₂ ) larger than the first amplitude (A ₁ ) during this time. The part 31 is vibrated ultrasonically (second step). Thus, by increasing the load applied to the protruding portion 31 and the amplitude of the protruding portion 31 in the latter half of the step of forming the fine through hole 41, more vibration energy can be applied and at the same time the fine through hole The shape of 41 is easily determined accurately, and the fine through hole 41 can be shaped with high accuracy and in a short time. Further, by taking these steps, in the first step, the vibration heating concentrates on the top portion 31a of the protruding portion 31 and the portion near the circular opening 41a of the fine through hole 41 in contact with the top portion 31a, but in the second step, Since the contact area increases, it is possible to cope with the necessity of giving more vibration energy.

Furthermore, according to the present embodiment, after the second step, the descent of the ultrasonic molding die 30 is stopped and the ultrasonic vibration of the protruding portion 31 is stopped, and the load is applied to the second load (P _{2) in} this state. ) (Holding load) and hold for a certain time (holding step). As a result, the base material sheet 20 that has been locally softened or melted can be cooled and solidified, and the shape of the fine through-hole 41 shaped with high accuracy can be maintained, and the protruding portion 31 can be replaced with the fine through-hole 41. It can be easily removed from.

Furthermore, according to the present embodiment, it is determined by detecting that the load applied to the protruding portion 31 has reached the contact load (P ₀ ) that the protruding portion 31 has contacted the base sheet 20. Therefore, it has a contact detection function for the base material sheet 20 and can perform accurate detection control. In addition, the fact that the protruding portion 31 is in contact with the back sheet 12 is determined by detecting that the load applied to the protruding portion 31 has reached the second load (P ₂ ). It is possible to accurately detect the stop position.

<Fine through-hole molded product>
Next, the configuration of the fine through-hole molded product 40 formed by the fine through-hole forming apparatus 10 will be described with reference to FIGS. 10 and 11. FIG. 10 is a plan view showing a fine through-hole molded product, and FIG. 11 is a cross-sectional view taken along the line XI-XI of FIG.

  A fine through-hole molded product 40 shown in FIGS. 10 and 11 is manufactured by molding the base sheet 20 using the fine through-hole forming apparatus 10. Such a fine through-hole molded product 40 is used as a member that exhibits various functions, such as a filter member, a breathable member, and a mesh for generating fine droplets used in a nebulizer. As a material constituting such a fine through-hole molded article 40, various heat-meltable resins as described above, for example, polycarbonate (PC), amorphous polyethylene terephthalate (A-PET), crystalline polyethylene terephthalate, stretched Include polyethylene terephthalate, methacrylic acid ester polymer (PMMA), polystyrene (PS), and ABS. In addition, polysulfone (PSU), polyethersulfone (PES), polyetheretherketone (PEEK), polyamideimide (PAI), polyetherimide (PEI), thermoplastic polyimide (TPI), polymethylpentene (PMP), super High molecular weight polyethylene (UHMWPE), liquid crystal polymer (LCP), polyarylate (PAR), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyacetal (POM), Thermoplastics such as polyamide (PA), polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) can also be applied.

  As shown in FIGS. 10 and 11, the fine through-hole molded product 40 has a molded product main body 42 and a plurality of fine through-holes 41 formed over the entire molded product main body 42. Each fine through hole 41 is formed by each protruding portion 31 of the ultrasonic forming die 30, and thus has a shape corresponding to the shape of each protruding portion 31. Each fine through hole 41 includes a circular opening 41a provided on one surface 42a of the molded product main body 42, and a slope 41b extending from the circular opening 41a toward the circular opening 42b on the other surface of the molded product main body 42. Have. The slope 41b may be a straight line or a curve, but in particular, when the fine through-hole molded product 40 is used as a mist forming filter as will be described later, the cone-shaped through-hole in which the slope 41b becomes a parabola. It is preferable that Further, reference numeral 40a denotes a hole peripheral part formed at the peripheral edge of the circular opening 41a, reference numeral 40b denotes a connecting part formed between adjacent fine through holes 41, and reference numeral 40c denotes a fine through hole. 41 is a thick portion formed around 41.

As shown in FIG. 11, the diameter of the through hole is different between the front and back of the fine through hole molded product 40 in the Conede-shaped through hole in which the slope portion 41 b is a parabola. For example, the diameter d ₂ of the circular opening 41a of each fine through hole 41 is preferably about 1 μm to 10 μm, for example. The diameter d ₃ of the circular opening 42b, for example is preferably about 20Myuemu～80myuemu. The number of through-holes 41 is preferably about 200 to 1000 per mm ² per unit area of the fine through-hole molded product 40, and the adjacent circular openings 41 a are necessary for each through-hole 41 to have the above number. distance L ₂ between each other, for example, is preferably about 32Myuemu～70myuemu. Furthermore, the thickness t ₂ of the fine through-hole molded product 40 is preferably about 10 μm to 100 μm, for example.

  The fine through-hole molded product 40 as described above can be suitably used as a mist forming filter of a mist generating device such as a nebulizer. For example, as shown in FIG. 12, the fine through-hole molded product 40 (mist forming filter 54) is disposed between the ultrasonic vibrator 51 and the mist generating port 52 of the mist generating device 50. The liquid 53 supplied onto the ultrasonic transducer 51 forms granular droplets 53a by vibration energy from the ultrasonic transducer 51, but the droplets pass through the through holes of the mist forming filter 54. By being discharged to the mist generating port 52, a droplet 53a having a desired particle diameter can be formed. By arranging the fine through-hole molded product 40 such that the side with the larger diameter of the through-hole molded product 40 provided with through-holes with different diameters on the front and back as described above is the ultrasonic transducer 51 side. A mist having a particle size of the droplet 53a of about 1 to 10 μm can be formed.

<Modification>
In the above-described embodiment, when a large number of fine through holes 41 are formed in the base sheet 20, the load applied to the protrusion 31 after the protrusion 31 abuts on the base sheet 20 is a second load ( The amplitude of the protrusion 31 is increased in two steps while increasing in two steps until P ₂ ) (holding load). However, the present invention is not limited to this, and the amplitude of the protrusion 31 may be increased in three or more steps while increasing the load applied to the protrusion 31 to the holding load in three or more steps. . For example, in accordance with the contact area S (projected area with respect to the surface of the base sheet 20) of the protrusion 31 (see FIG. 8), the load applied to the protrusion 31 is increased to the holding load in three or more steps. The amplitude of the protrusion 31 may be increased in three or more steps.

In the above-described embodiment, when increasing the amplitude of the protruding portion 31 stepwise while increasing the load applied to the protruding portion 31 to the second load (P ₂ ) (holding load) stepwise, The step is switched when the protrusion 31 reaches a certain load (first load (P ₁ ), second load (P ₂ )). However, the present invention is not limited to this, and each step may be switched when a predetermined time is reached after the movement of the protruding portion 31 is started. For example, when the predetermined time T ₁ (FIG. 9) is reached, the first process is switched to the second process, and when the predetermined time T ₂ (FIG. 9) is reached, the second process is switched to the holding process. good.

Alternatively, the tip position of the protruding portion 31 may be constantly monitored, and each step may be switched when the protruding portion 31 has reached a predetermined position. For example, when it is detected that the protrusion 31 has reached a predetermined intermediate position (Z ₃ ) (FIG. 8C, FIG. 9), the first process is switched to the second process, and the protrusion 31 is predetermined. When it is detected that the lower end position (Z ₄ ) (FIG. 8D, FIG. 9) has been reached, the second process may be switched to the holding process.

  Furthermore, monitoring of these set values may proceed simultaneously, and if there is one that has detected that the set value has been reached in advance, it may be switched from the first step to the second step with priority. The second process may be switched to the holding process.

DESCRIPTION OF SYMBOLS 10 Fine through-hole shaping | molding apparatus 11 Base 12 Back sheet 12a Back sheet peeling layer 13 Suction part 14 Heating device 15 Mold control apparatus 16 Temperature control apparatus 20 Base material sheet 30 Ultrasonic molding die 31 Projection part 32 Horn head 33 Base Part 40 Fine through-hole molded product 41 Fine through-hole 42 Molded product main body 50 Mist generator 51 Ultrasonic vibrator 52 Mist generating port 53 Liquid 54 Mist forming filter

Claims (13)

A cradle, a back sheet that is held on the cradle and has heat resistance and supports a base sheet made of synthetic resin, and an ultrasonic molding that is disposed above the back sheet and has a large number of protrusions at the lower part The ultrasonic molding die is movable in the vertical direction, and ultrasonically vibrates in the vertical direction to vibrate and heat the base sheet to melt and melt the base sheet into a large number of fine penetrations. In a method of manufacturing a fine through-hole molded product using a fine through-hole forming device that forms holes,
A step of lowering the position of the ultrasonic molding die until the protruding portion is directly above the base sheet, and
The control of the ultrasonic mold is switched from position control to load control, and the ultrasonic mold is further lowered, and the protrusion of the ultrasonic mold is ultrasonically vibrated so that the protrusion penetrates the base sheet. Forming a large number of fine through holes in the substrate sheet.   The process of forming a large number of fine through-holes in the base sheet is the step of increasing the load applied to the protrusions step by step up to the holding load after the protrusions contact the base sheet. The method according to claim 1, further comprising a penetration step of gradually increasing the amplitude of ultrasonic vibration.   After the penetration step, there is provided a holding step for stopping the descent of the ultrasonic molding die and stopping the ultrasonic vibration of the protruding portion, and holding the load for a certain time in this state. Item 3. The method according to Item 2.   The method according to claim 2, wherein the contact of the projecting portion with the base sheet is determined by a load applied to the projecting portion reaching a contact load.   The method according to claim 3, wherein after the holding step, the protruding portion is ultrasonically vibrated again while maintaining a load applied to the protruding portion at the holding load.   The method according to claim 3, wherein after the holding step, the ultrasonic mold is raised, and the protrusion is ultrasonically vibrated again.   7. The method according to claim 1, further comprising a step of raising the ultrasonic mold after the step of forming a large number of fine through holes in the base material sheet and extracting the protruding portion from the base material sheet. The method described in 1.   The fine through-hole molded article obtained by the method as described in any one of Claims 1 thru | or 7.   A mist-forming filter in which a large number of fine through-holes are formed on a synthetic resin base material sheet, wherein the mist-forming filter is obtained by the method according to any one of claims 1 to 7. Mist characterized in that the diameter of the through hole is different between the front and back of the base sheet, the diameter of one surface is 1 to 10 μm, and the diameter of the other surface is 20 to 80 μm. Forming filter. The filter for mist formation according to claim 9, wherein the through holes are 200 to 1000 pieces / mm ² .   The filter for mist formation according to claim 9 or 10, wherein the through hole has a conical shape with a widening end.   A mist generating device that oscillates an ultrasonic transducer to mist a liquid, wherein the mist forming filter according to any one of claims 9 to 11 is disposed between the ultrasonic transducer and a mist generating port. The mist generator characterized by being provided.   The mist generating device according to claim 12, wherein the mist forming filter is disposed such that a side with a large diameter of the fine through hole is an ultrasonic transducer side.

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