JP2013090837A - Method for manufacturing needle-like body and needle-like body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a needle-like body which allows to manufacture a needle-like body hardly generating damage at a leading end part during puncture to skin and transfer to a duplicate plate with a simple method.SOLUTION: The method for manufacturing a needle-like body 15 includes steps of: forming an etching mask 12 on a substrate 11, wherein a part or the whole of an outer shape of the bottom surface part is arc-shaped and in which a thickness is continuously increased from a peripheral part to a central part; forming a needle-like structure 13 on the substrate by performing etching treatment using the etching mask 12; and forming an upper inclined surface 14 in the structure 13.

Description

  The present invention relates to a method for manufacturing an acicular body and an acicular body.

  A percutaneous absorption method is known as a method of infiltrating a drug from the skin and administering the drug into the body. In this method, a liquid or gel-like drug is applied to the surface of a living body such as skin or mucous membrane.

  This method is non-invasive and allows a drug to be easily administered without causing pain to the human body. However, the applied drug is easily removed by perspiration or external contact. In addition, if the administration period is long, problems such as skin damage may occur in terms of safety. Furthermore, when the target drug has a large molecular weight or is a water-soluble drug, it is hardly absorbed into the body even when applied to the surface of a living body, and it is difficult to administer these drugs transdermally.

  Therefore, in order to efficiently absorb these drugs into the body, attention has been paid to a method of perforating the skin using an array of a large number of micron-order needles and directly administering the drug into the skin. According to this method, a drug can be easily administered intradermally without using a special device for medication (see, for example, Patent Documents 1 and 2).

  The shape of the needle-like body is required to have a sufficient fineness and a tip angle for piercing the skin and a sufficient length for allowing the drug solution to penetrate into the skin. For this reason, the diameter of the needle-shaped body is several μm to several hundred μm, and the length penetrates through the stratum corneum, which is the outermost layer of the skin, and does not reach the nerve layer, specifically several tens μm to several hundreds It is considered desirable to be μm.

  The material constituting the acicular body is required not to adversely affect the human body even if the acicular body is damaged and remains in the body. As such materials, biocompatible resins such as medical silicone resins, maltose, polylactic acid, dextran, and the like are considered promising (see Patent Document 3).

  However, many of the needles that have been proposed so far have a sharp pointed shape, and needles made of a material with low mechanical strength can be used for puncturing the skin and for copying. There has been a problem that the tip is easily damaged during transfer or the like.

JP 2006-345993 A JP 2006-341089 A Japanese Patent Laid-Open No. 2005-21677

  SUMMARY OF THE INVENTION An object of the present invention is to provide a needle-shaped body manufacturing method that makes it possible to manufacture a large number of needle-shaped bodies that are unlikely to be damaged at the tip when puncturing the skin and transferring to a duplicate plate. Is to provide.

  The method for producing a needle-shaped body of the present invention is a process of forming an etching mask on a substrate, in which part or all of the outer shape of the bottom surface is an arc shape and the thickness continuously increases from the peripheral edge to the center. And a step of forming a needle-like structure on the substrate by performing an etching process using the etching mask, and a step of forming an upper slope on the structure.

  In addition, the method for manufacturing a needle-shaped body according to the present invention further includes a step of forming a non-through hole in the substrate, and the bottom surface is formed on a surface of the substrate opposite to the surface on which the non-through hole is formed. An etching mask may be formed in which a part or all of the outer shape of the part has an arc shape and the thickness continuously increases from the peripheral part to the central part.

  The etching mask can be formed by patterning a resist on a substrate and then reflowing the resist. The etching may be anisotropic dry etching. Further, the step of forming the upper slope may be performed by grinding.

  Furthermore, the present invention also includes a needle-like body manufactured by the above method.

  According to the method for manufacturing a needle-shaped body of the present invention, it is possible to manufacture a large amount of needle-shaped bodies having a rounded tip by a simple method. Since the needle-like body manufactured by the manufacturing method of the present invention has a rounded tip portion, the tip portion is unlikely to break when puncturing the skin and transferring to a duplicate plate. Accordingly, it is possible to improve the puncturing performance to the skin and the yield in transfer molding of the needle-like body.

It is sectional drawing which shows an example of the manufacturing method of the acicular body of this invention. It is sectional drawing which shows the other example of the manufacturing method of the acicular body of this invention. It is a perspective view which shows an example of the acicular body manufactured by the manufacturing method of the acicular body of this invention. It is the perspective view and top view which show the other example of the acicular body manufactured by the manufacturing method of the acicular body of this invention.

  Hereinafter, an example of the manufacturing method of the acicular body of this invention is demonstrated. 1A to 1C are cross-sectional views showing an example of a method for producing a needle-shaped body of the present invention.

  First, an etching mask 12 is formed on a substrate 11 as shown in FIG. Here, the material constituting the substrate 11 may be any material that can be processed by wet etching, dry etching, or the like. For example, a metal such as titanium, aluminum, or stainless steel, or a synthetic material such as polycarbonate, polystyrene, acrylic resin, or fluorine resin. Resin, silicon, etc. are mentioned.

  In addition, the etching mask 12 includes a circular arc shape in part or all of the outer shape of the bottom surface portion, and has a shape in which the thickness continuously increases from the peripheral edge portion to the central portion. The etching mask 12 in FIG. 1A has a circular bottom surface (that is, the entire outer shape of the bottom surface includes an arc shape). The etching mask 12 having such a shape can be formed, for example, by patterning a resist on the substrate 11 in a circular shape and then reflowing the resist.

  Next, as shown in FIG. 1B, an acicular structure 13 is formed on the substrate 11 by performing an etching process using the etching mask 12. Here, since the thickness of the etching mask 12 continuously increases from the peripheral portion to the central portion, the etching mask 12 is gradually removed from the peripheral portion as the etching proceeds. As a result, the substrate 11 can be processed into a tapered shape.

  The etching is preferably anisotropic dry etching, for example, various discharges such as electron cyclotron resonance (ECR), inductively coupled plasma (ICP), magnetic neutral line discharge (NLD), microwave, helicon wave, etc. It is desirable to perform dry etching using a method.

  Further, by controlling the size and height of the etching mask 12, the base size and side wall angle (angle formed by the side wall with respect to the vertical direction) of the structure 13 obtained by processing the substrate 11 into a needle shape are obtained. Can be controlled.

  Next, as shown in FIG. 1 (c), an upper slope 14 is formed on the structure 13, and a needle-like body 15 is formed. The step of forming the upper slope 14 can be suitably performed by grinding. For example, a dicing blade may be used as a grinding tool.

  Here, the direction of the upper slope 14 is made to correspond to the direction in which the tip portion forms an arc shape. As a result, the needle-like body 15 having a rounded tip as shown in FIG. 3 is obtained.

  In addition, the inclination angle of the upper slope 14 is appropriately adjusted according to the required tip angle of the needle-like body 15.

  Since the needle-like body manufactured by the method for manufacturing a needle-like body according to the present invention has a rounded tip, the tip is hardly damaged at the time of puncturing the skin, transferring to a duplicate plate, or the like. Therefore, it is possible to improve the puncturing performance to the skin and the yield in transfer molding of the needle-like body.

  Further, by arranging the etching mask 12 on the substrate 11 in a plurality of arrays, it is possible to manufacture a large number of needle-like bodies by a simple process.

  Next, an example of the manufacturing method of the needlelike object of the present invention which has a penetration hole is explained using Drawing 2 (a)-(d).

  First, as shown in FIG. 2A, the non-through hole 22 is formed in the substrate 21. Here, in the step of forming the non-through hole 22, various known techniques such as wet etching, dry etching, laser processing, and machining can be used.

  Next, as shown in FIG. 2B, an etching mask 23 is formed on the substrate 21 on the surface opposite to the surface where the non-through holes 22 are formed.

  Here, the etching mask 23 has an arc shape in part or all of the outer shape of the bottom surface portion, and has a shape in which the thickness continuously increases from the peripheral edge portion to the central portion. Further, in the step of forming the etching mask 23, the etching mask 23 and the previously formed non-through hole 22 are aligned.

  Next, as shown in FIG. 2C, the needle-like structure 24 is formed on the substrate 21 by performing an etching process using the etching mask 23. At this time, in the structure 24, the previously formed non-penetrating hole 22 may be penetrated as shown in FIG. 2C or may be left unpenetrated.

  Next, as shown in FIG. 2 (d), by forming an upper slope 26 in the structure 24, a needle-like body 27 having a through hole 25 is obtained.

  Hereinafter, the manufacturing method of the needlelike object of the present invention is explained by an example.

Example 1
Reference is made to FIGS.
First, a photoresist layer having a thickness of 25 μm was formed by a spinner on a substrate 11 made of single crystal silicon having a thickness of 725 μm, and then exposed and developed to form a circular dot pattern having a diameter of 300 μm (not shown). Next, the resist pattern was reflowed at 150 ° C. to form an arc-shaped etching mask 12 having a height of 35 μm as shown in FIG.

  Next, as shown in FIG. 1B, the substrate 11 was processed into a needle shape by subjecting the substrate 11 to dry etching treatment using a fluorocarbon-based mixed gas plasma using the etching mask 12 as a mask. Here, the base size of the obtained needle-like structure 13 was 200 μm, the height was 500 μm, and the side wall angle was 11 °.

  Next, as shown in FIG. 1C, the upper slope 14 having an inclination angle of 30 ° was formed on the structure 13 by grinding using a dicing blade. As a result, as shown in FIG. 3, a needle-like body 15 having a height of 350 μm with a rounded tip was obtained.

(Example 2)
Reference is made to FIGS.

  First, as shown in FIG. 2A, by subjecting a substrate 21 made of single crystal silicon having a thickness of 725 μm to a dry etching process using photolithography and a fluorocarbon-based mixed gas plasma, a diameter of 30 μm and a depth of 30 μm are obtained. A 500 μm non-through hole 22 was formed.

  Next, as shown in FIG. 2B, an etching mask 23 was formed on the substrate 21 on the surface opposite to the surface where the non-through holes 22 were formed. The etching mask 23 was formed at a position shifted by 10 μm with respect to the non-through hole 22.

  Next, as shown in FIG. 2C, the needle-like structure 24 was formed on the substrate 21 by performing an etching process using the etching mask 23.

  Next, as shown in FIG. 2 (d), an upper slope 26 is formed on the structure 24, so that a needle-like body 27 having a height of 350 μm having a rounded tip and a through hole 25 having a diameter of 30 μm. was gotten.

  In the above embodiment, the bottom surface portion is circular (the outer shape of the bottom surface portion) using an etching mask in which the entire outer diameter shape of the bottom surface portion is an arc shape and the peripheral edge portion continuously increases in thickness toward the center portion. Is a circular arc shape), and a needle-like body having a conical side wall whose outer diameter gradually decreases from the bottom toward the top and an upper slope having a slope angle gentler than the slope angle of the side wall is formed. Although described, the present invention is not limited to this.

  For example, by using an etching mask in which a part of the outer diameter shape of the bottom part is an arc shape and a part is a notch part and the peripheral part continuously increases in thickness toward the center part, FIG. , (B), a needle-like body having a shape as shown in FIG. 4A is a perspective view of the needle-like body 42, and FIG. 4B is a plan view of FIG. 4A. That is, the needle-like body 42 in FIG. 4 has a configuration in which a notch groove 41 is formed from the bottom surface portion to the upper slope.

  DESCRIPTION OF SYMBOLS 11, 21 ... Substrate, 12, 23 ... Etching mask, 13, 24 ... Structure, 14, 26 ... Upper slope, 15, 27, 42 ... Needle-like body, 22 ... Non-through hole, 25 ... Through hole, 41 ... Notch groove.

Claims (6)

On the substrate, forming an etching mask in which a part or all of the outer shape of the bottom surface portion is an arc shape and the thickness continuously increases from the peripheral edge portion to the central portion;
Forming an acicular structure on the substrate by performing an etching process using the etching mask;
And a step of forming an upper slope on the structure.   The method further includes the step of forming a non-through hole in the substrate, wherein a part or all of the outer shape of the bottom surface portion has an arc shape on a surface of the substrate opposite to the surface where the non-through hole is formed. The method of manufacturing an acicular body according to claim 1, wherein an etching mask having a thickness that continuously increases from a peripheral portion to a central portion is formed.   3. The method for manufacturing a needle-shaped body according to claim 1, wherein the etching mask is formed by reflowing the resist after patterning the resist on the substrate.   The method for manufacturing a needle-shaped body according to any one of claims 1 to 3, wherein the etching is anisotropic dry etching.   5. The method for manufacturing a needle-shaped body according to claim 1, wherein the step of forming the upper slope is performed by grinding.   An acicular body manufactured by the manufacturing method according to any one of claims 1 to 5.

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