JP5083276B2 - Micromachining tool and brittle material micromachining method - Google Patents

Description

  The present invention provides a micromachining tool suitable for use in forming fine grooves, holes, recesses and the like having a width, depth, diameter and the like of 100 μm or less on the surface of a brittle material such as glass and ceramics, and the like. The present invention relates to a fine processing method of a brittle material using a fine tool for fine processing.

In recent years, attention has been focused on a micro reaction system represented by a micro TAS for mixing and separating solution samples in a fine analysis channel. In Patent Document 1, as a chip used in this micro reaction system, a glass substrate is formed by slitting with a fine width of 200 μm on the processing surface side and 130 μm on the surface opposite to the processing surface by sandblasting. It is described that the flow path as described above is formed inside by sandwiching the substrate between two other glass substrates. In Patent Document 2, such a slit is formed by CO ₂ laser irradiation. In Patent Document 3, a groove is formed on the glass substrate surface by photoresist etching, and another glass substrate is formed thereon. It is described that a flow path is formed by bonding.

JP 2004-117279 A JP 2004-53559 A JP 2004-210592 A

  However, among these, the processing by sandblasting in Patent Document 1 and photoresist etching in Patent Document 3 makes it difficult to ensure dimensional accuracy such as the width and depth of slits and grooves, and takes a lot of time to form them. It will be necessary. Further, in the processing by laser as in Patent Document 2, the processing apparatus is extremely expensive, and an inexpensive micro reaction system chip cannot be provided. Furthermore, in these processing methods, the width of the slits and grooves can only be reduced to about several hundred μm, and for example, it has been impossible to perform further fine processing having a width and depth of 100 μm or less. .

  On the other hand, the inventors of the present invention, for example, in JP-A-2002-355710, JP-A-2004-160581, or JP-A-2005-22102, provide tools for processing brittle materials such as glass and ceramics. As a tool base material such as a cemented carbide alloy with a hard carbon coating such as a diamond coating. According to such a tool, unevenness of hard carbon particles such as diamond grown on the coating is proposed. Acts as a cutting edge, and drilling and grooving can be performed without causing chipping or peeling on a workpiece made of a brittle material. However, in these tools, for example, in Japanese Patent Application Laid-Open No. 2002-355710, a convex curved surface is formed at the tip of a tool base material having an outer diameter of 0.2 to 3 mm, and a predetermined cutting edge shape having a convex curve shape is formed. A tool that can be formed and coated with a hard carbon coating of 5 to 25 μm, and based on this, can form grooves, holes, and recesses with a width, depth, diameter of 100 μm or less as described above. For this purpose, the shape of the cutting edge has to be formed at the tip of a tool base material having an outer diameter of less than 100 μm, and it has been difficult to directly apply it to microfabrication of a chip for a micro reaction system.

  The present invention has been made under such a background, and the width, depth, and diameter of the surface of a workpiece made of a brittle material such as glass or ceramics in the microfabrication of a chip for a micro reaction system as described above. For the purpose of providing a micromachining tool capable of forming fine grooves, holes, recesses and the like of 100 μm or less, and a micromachining method of a brittle material using such a micromachining tool Yes.

In order to solve the above problems and achieve such an object, the micromachining tool of the present invention has a hard carbon film coated on the tip formed on the tool body, and the film of the hard carbon film The thickness is larger than the outer diameter at the tip of the tip, and the hard carbon coating forms a cutting edge portion having a substantially convex curved surface at the tip of the tip, and the tip has a tip angle. It is formed in a conical shape within a range of 10 to 60 °, and the surface of the cutting edge portion is formed in a substantially spherical shape having a center on the center line of the cone formed by the tip portion at the tip of the tip portion. It is characterized by that. Further, the brittle material micromachining method of the present invention uses such a micromachining tool to rotate the tool main body around the center line of the pointed portion while the cutting edge portion is made of a brittle material. The above-mentioned workpiece is finely processed by being cut into the surface of the substrate.

In the micromachining tool having the above-described configuration, the film thickness of the hard carbon film coated on the tip of the tool body is larger than the outer diameter at the tip of the tip, and the hard carbon film is formed on the tip of the tip. Since hard carbon particles grow and coat from the surface almost isotropically, the surface of the cutting edge portion formed at the tip of the tip by this hard carbon coating forms a convex curved surface at the tip. Even if it does not, it will exhibit a substantially convex curved surface shape. And since the tip part is formed in the shape of a tapered cone , and the hard carbon particles grow in a spherical shape from one point of the tip part of the tip part, the surface of the cutting edge part has the tip part at the tip of the tip part. It is formed in a substantially hemispherical shape having a center on the center line of the cone .

On the other hand, even if the tip angle when the tip is conical is within the range of 10 to 60 ° and extremely narrow, the outer diameter of the cutting edge is within the range of 10 to 100 μm and the minimum diameter, The rigidity and strength of the cutting edge are ensured by the high hardness of the hard carbon coating itself. The hard carbon particles thus grown form extremely fine irregularities on the surface of the cutting edge, and each of the irregularities acts as a cutting edge. The cutting edge is cut into the surface of a work piece made of a brittle material while rotating around the center line of the tip, and in the case of grooving, the tip of the tool is sent out in a direction crossing the center line. Since the part is conical and the surface of the cutting edge is spherical at the tip of the tip , the width and depth of the work piece made of a brittle material such as glass can be reduced. It is possible to form extremely fine grooves of 100 μm or less that are substantially equal to the outer diameter. Moreover, when forming a hole and a recessed part, what is necessary is just to advance in the said centerline direction as it is by cutting a cutting-blade part into the workpiece surface, rotating a tool main body around the centerline of a pointed part. At this time, since the tip is conical , it is possible to form a tapered hole in which the inner diameter of the hole gradually increases toward the opening.

  Therefore, according to such a tool for micromachining and a micromachining method for a brittle material using the tool, the tool shape is simple and the manufacturing is easy, so that it is much cheaper than laser machining and the like. Due to the processing, it is possible to form ultrafine grooves, holes, recesses and the like having a width and depth of 100 μm or less on the glass substrate in a shorter time than processing by sandblasting or photoresist etching. Moreover, in such a cutting process, since the shape of the cutting edge portion is transferred to the workpiece as it is, high processing accuracy can be obtained with respect to the groove width and depth, or the diameter of the hole and the recess, etc. Although it is inexpensive, it is possible to provide a high-quality micro reaction system chip with high dimensional accuracy of the flow path.

  Here, in the fine processing tool, it is desirable that the film thickness of the hard carbon coating is in the range of 5 to 50 μm. That is, if the film thickness exceeds 50 μm, the outer diameter of the cutting edge portion exceeds 100 μm, so that it may be impossible to form the extremely fine groove as described above. In addition, if the film thickness is too thick, the projections acting as cutting edges vary in size, which may impair processing accuracy. On the other hand, if the film thickness is thinner than 5 μm, the cutting edge portion cannot have sufficient rigidity and strength, and breakage or the like tends to occur, which may shorten the tool life.

A first reference example of in describing the embodiments of the micro-machining tool of the present invention is a side view showing. It is an expanded sectional view of the tip part 4 tip side of the reference example shown in FIG. It is an expanded sectional view of the tip part 11 tip side showing the embodiment of the tool for fine processing of the present invention. It is an expanded sectional view of the tip part 21 tip side showing the 2nd reference example of the tool for fine processing of the present invention. It is an expanded sectional view of the tip part 31 tip side showing the 3rd reference example of the tool for fine processing of the present invention.

1 and 2 show a first reference example for explaining an embodiment of a micromachining tool of the present invention. In this reference example , the tool body 1 has a substantially two-stage cylindrical shape centering on the center line O with a hard material such as cemented carbide or ceramics as the base material, and the rear end side (the lower side in FIG. 1). The portion is a shank portion 2 having a constant outer diameter and a large diameter, and a conical portion 3 that gradually decreases in diameter toward the distal end side on the distal end side (the upper side in FIGS. 1 and 2) of the shank portion 2, The pointed portion 4 is formed integrally and coaxially.

The pointed portion 4 is formed in an extremely thin cylindrical shaft shape, that is, a cylindrical surface that extends from the conical portion 3 toward the tip side with a constant outer diameter d around the center line O. A surface 4A and a circular tip surface 4B having the outer diameter d centered on the center line O perpendicular to the peripheral surface 4A and the center line O are provided at the tip of the peripheral surface 4A. Here, the outer diameter d is in the range of 5 to 33 μm.

Then, the tool body 1 surface toward the tip 4 from the cone 3, the hard carbon coating 5 is covered as shown in FIG. 2, the diameter a thickness t is at the tip of the pointed end 4, i.e. It is larger than the outer diameter d. Here, the hard carbon coating 5 is, for example, a diamond coating film by a known method such as vapor-phase synthesis method is coated by growing diamond particles (hard carbon particles) on the surface of the tool body 1, the thickness As described above, the coating is performed so that the thickness is substantially constant larger than the outer diameter d within a range where t is 5 to 50 μm. The surface of the shank portion 2 is not covered with such a hard carbon coating 5, and has an outer diameter obtained by molding the tool body 1 and finishing the outer periphery of the shank portion 2.

In the tip portion 4 of the tool body 1 thus coated with the hard carbon coating 5, the hard carbon coating 5 is coated around the peripheral surface 4A so as to form a cylindrical shape with a constant film thickness t. On the outer peripheral side in the radial direction of the peripheral surface 4A, the outer shape remains cylindrical with the center line O as the center, and the outer diameter D is d + 2t. In the first reference example, the outer diameter D is in the range of 10 to 100 μm. It is supposed to be inside. On the other hand, at the tip of the tip portion 4, the hard carbon coating 5 is formed in a columnar shape so that the tip portion 4 is directly extended by the length of the film thickness t from the tip surface 4B toward the tip side along the center line O. Covered, and from the periphery of this cylindrical portion to the tip of the cylindrical portion around the peripheral surface 4A, the intersecting ridge line portion where the peripheral surface 4A and the front end surface 4B intersect (the circumference of the outer periphery of the front end surface 4B) 1), the hard carbon particles grow isotropically and extend from the outer periphery of the cylindrical portion to the tip of the cylindrical portion with a radius of the film thickness t around the intersecting ridge line portion in the cross section along the center line O. The hard carbon film 5 is coated in a 4-circle fan shape.

Therefore, the surface of the hard carbon coating 5 at the tip of the tip 4 has a rectangular shape extending from the tip surface 4B between the ¼ circles on both sides as shown in FIG. By forming a semi-oval shape that is flattened with the center line O as the short axis between which the portion is sandwiched, the ¼ circle section on both sides is formed in a convex curved shape. And the surface of this hard carbon film 5 includes innumerable fine irregularities due to the grown hard carbon particles including the portion coated around the peripheral surface 4A. The cutting edge portion 6 is formed by the hard carbon coating 5 coated on the tip portion 4. Therefore, in the first reference example, the surface of the cutting edge portion 6 has a semi-oval shape as described above in the cross section along the axis O, and the corner portion between the bottom edge and the outer peripheral edge is R-shaped. The turning locus of the cutting edge is the same as that of the corner R-end mill or radius end mill.

In the micromachining method of the brittle material using the micromachining tool configured as described above, the above-described cutting is performed while holding the shank portion 2 on the spindle of the machine tool and rotating the tool body 1 around its center line O. The blade 6 is cut into the surface of a work piece made of a brittle material such as glass or ceramics, and the tool body 1 is sent out perpendicular to the axis O along the surface of the work piece. The workpiece is scraped off by the above-mentioned extremely fine cutting edge made of hard carbon particles, and grooves and the like are formed on the surface. The width and depth of the groove formed in this way depend on the amount of cutting of the cutting edge portion 6 into the workpiece, but only the portion of the cutting edge portion 6 on the tip side of the tip surface 4B of the tip portion 4 is used as the workpiece. Assuming that the groove is cut, it is possible to form an extremely fine groove having a groove width of the outer diameter D or less, that is, 100 μm or less, and a groove depth of the film thickness t or less, that is, 50 μm or less.

As described above, in the micromachining tool of the first reference example and the micromachining method of the brittle material using the same, an extremely fine groove can be formed on the surface of the workpiece made of the brittle material. It can be used to form grooves in a glass substrate for forming a flow path in a chip for a micro reaction system, which can form a finer flow path than conventional sandblasting, photoresist etching, or laser processing. Therefore, it is possible to provide a chip capable of analyzing with higher accuracy. Further, in the cutting process using such a tool, it is possible to form a groove or the like in which the shape of the cutting edge portion 6 is transferred as it is. Processing with high dimensional accuracy can be achieved, and analysis with higher accuracy can be promoted. In addition, tools and machine tools are extremely cheap compared to laser processing machines, etc., and they can be formed more efficiently in a shorter time than sandblasting and photoresist etching, so they are cheaper. It is also possible to provide a chip.

Further, in the fine processing tool having the above-described configuration, the cutting edge portion 6 is formed on the cylindrical shaft-shaped tip portion 4 in the first reference example, and the hard carbon film having a film thickness t larger than the diameter of the tip portion of the tip portion 4. 5 is formed only by coating, and each of the innumerable convex portions of the hard carbon particles protruding on the surface of the hard carbon coating 5 acts as a cutting edge. 4. It is not necessary to sharpen and form the same cutting edge as the radius end mill whose rotational trajectory has the cross-sectional shape as described above, and it is possible to provide a more inexpensive tool that is simple and easy to manufacture. It becomes. On the other hand, the cutting edge portion 6 is formed by coating the hard carbon film 5 having high hardness around the tip portion 4 with a film thickness t larger than the outer diameter d of the tip portion 4. Even if the outer diameter D is very small as described above, sufficient hardness and strength can be ensured by the hardness of the hard carbon coating 5 itself, and the tip 4 may be bent or broken during processing. Therefore, it is possible to extend the tool life by preventing such a situation, so that it is possible to provide a more inexpensive insert.

In order to achieve such an effect more reliably, the film thickness t of the hard carbon coating 5 is desirably in the range of 5 to 50 μm, and the outer diameter D of the cutting edge portion 6 is 10 to 100 μm. In the case where the tip 4 is axial as in the first reference example , the outer diameter d is preferably in the range of 5 to 33 μm. That is, when the film thickness t exceeds 50 μm, the hard carbon particles grow isotropically as described above, and therefore the outer diameter D of the cutting edge portion 6 cannot be reduced to 100 μm or less. This may not be possible, and this is the same when the outer diameter d of the tip 4 exceeds 33 μm. Moreover, when the film thickness t becomes too thick, the size of the convex part on the surface of the cutting edge part 6 acting as a cutting edge may vary, which may impair the processing accuracy.

On the other hand, when the film thickness t is less than 5 μm and the outer diameter D of the cutting edge portion 6 is less than 10 μm, the hard carbon coating 5 cuts even though the hardness is high. There is a possibility that sufficient strength and rigidity of the blade portion 6 cannot be secured. Further, it is difficult to form the pointed portion 4 having an outer diameter d of less than 5 μm, and there is a possibility that the tip portion 4 may be deformed when the hard carbon coating 5 is coated. In the fine processing tool of the first reference example in which the hard tip 4 is coated with the hard carbon film 5, the film thickness t is the outer diameter d in order to make the outer diameter D of the cutting edge portion 6 100 μm or less. However, when the film thickness t is 5 μm or more, the outer diameter D is larger than 10 μm by the outer diameter d.

Next, FIG. 3 is a cross-sectional view of the tip side portion of the tip portion 11 showing an embodiment of the micromachining tool of the present invention, and the micromachining tool of the first reference example shown in FIGS. 1 and 2. The same reference numerals are assigned to the elements common to and the description is omitted. That is, in this embodiment , the tip portion 11 has a tapered conical shape with the center line O of the tool body 1 as the center, and the tip portion 11 is covered with the hard carbon coating 5 and the cutting edge portion 6 is covered. Is formed. Here, the included angle between the generatrices in the cross section along the centerline O of the cone formed by the tip 11, that is, the tip angle θ is within the range of 10 to 60 ° in the present embodiment. The film thickness t is in the range of 5 to 50 μm as in the first reference example .

In the micromachining tool according to such an embodiment , the hard carbon film 5 has hard carbon particles grown from the conical cone surface 11A formed by the tip 11 to a thickness t perpendicular to the cone surface 11A. The surface is covered in a truncated cone shape except for the tip, and at the tip of the tip 11, the hard carbon particles are isotropically radiused from the point 11B on the center line O of the cone with a film thickness t. It grows into an equal spherical shape and is coated in a substantially hemispherical shape centered on the protruding end 11B that smoothly contacts the tip of the frustoconical surface. Since the tip portion 11 has a conical shape, its outer diameter gradually decreases toward the front end side in the center line O direction, and the film thickness t becomes larger than the outer diameter of the tip portion 11 in the vicinity of the tip end 11B. Thus, a cutting edge portion 6 whose surface forms the convex surface of the hemispherical surface and the truncated cone surface is formed by the hard carbon coating 5 at the tip of the pointed portion 11. In the present embodiment, the outer diameter of the cutting edge portion 6 gradually decreases toward the front end side in the center line O direction, and the film thickness t is 50 μm or less. The outer diameter D of the blade part 6 (in this embodiment, the diameter between the intersections of the straight line extending perpendicularly from the protrusion 11B to the conical surface 11A and the surface of the hard carbon coating 5 in the cross section along the center line O) is 100 μm or less. Is done.

Therefore, in the micromachining tool of such an embodiment, the tip of the cutting edge portion 6 has a hemispherical shape similar to the rotation trajectory of the cutting edge of the ball end mill, and the radius thereof is that of the hard carbon coating 5. Since the thickness t is equal to the film thickness t, the micromachining method according to the embodiment of the present invention in which micromachining is performed on the brittle material using the tool in the same manner as in the first reference example also depends on the cutting depth . Similar to the reference example , it becomes possible to form a fine groove having a groove width of 100 μm or less in a workpiece made of a brittle material with a relatively short time and with high accuracy, and it is necessary to sharpen the cutting edge on the tip 11. In addition, since the tool itself and the machine tool are inexpensive, it is possible to provide an inexpensive chip for a microreaction system, although analysis with high accuracy is possible. Further, in the present embodiment, the tip portion 11 has a conical shape whose diameter gradually increases toward the rear end side, so that the rigidity and strength of the tip portion 11 itself can be easily secured, and no breakage or bending occurs. It is possible to obtain a tool for fine machining having a longer life.

In this embodiment, the tip angle θ of the cone formed by the pointed portion 11 is in the range of 10 to 60 °. However, if the tip angle θ is smaller than this, the increase in the diameter toward the rear end side is small. Therefore, the above-described effect cannot be obtained, and it is difficult to form the pointed portion 11 having such a small tip angle θ. On the other hand, if the tip angle θ is too large, the surface of the tip of the cutting blade 6 has a hemispherical portion and the tapered angle of the truncated cone surface portion also increases. There is a possibility that the groove width becomes large and it becomes difficult to perform extremely fine processing. For this reason, the tip angle θ is within the above range .

Further, FIG. 4 is a cross-sectional view of the tip side portion of the tip portion 12 showing a second reference example of the micromachining tool of the present invention. The first reference example and the embodiment shown in FIGS. The same reference numerals are assigned to elements common to the microfabrication tool, and description thereof is omitted. That is, in the second reference example , the tip 21 has a tapered conical surface with the peripheral surface 21A centering on the center line O of the tool body 1 like the conical surface 11A of the embodiment . However, the tip thereof is a circular tip surface 21B centering on the center line O orthogonal to the center line O similarly to the tip surface 4B of the first reference example , that is, a truncated cone shape. The pointed portion 21 is covered with the hard carbon coating 5 to form the cutting edge portion 6. Here, the included angle between the generatrices in the cross section along the center line O of the peripheral surface 21A of the truncated cone formed by the pointed portion 21, that is, the tip angle α is 60 ° or less, and the outer diameter of the tip surface 21B. e is 33 μm or less.

The cutting edge portion 6 in which the tip portion 21 is coated with the hard carbon coating 5 is formed such that the hard carbon coating 5 grows in a cylindrical shape from the tip surface 21B to the tip side, and the tip surface 21B and the peripheral surface. From the crossed ridge line portion with 21A, in the cross section along the center line O, the surface of the tip portion is grown to form a ¼ circle fan shape on the outer periphery of the columnar portion, so that the surface of the tip portion is the first reference example. Similarly to the above, the cross section has a semi-oval shape with the axis O as the short axis, and exhibits a cutting edge rotation locus similar to that of an end mill with a corner R or a radius end mill. In addition, on the outer peripheral side of the peripheral surface 21A, the hard carbon coating 5 having a frustoconical surface is formed so as to extend from the fan-shaped portion having the quarter cross section to the rear end side. It should be noted that the outer diameter D at the distal end portion of the cutting edge portion 6 on which the hard carbon coating 5 is thus formed (in the second reference example , the circumferential surface from the intersection of the circumferential surface 21A and the distal end surface 21B in the cross section along the center line O) The diameter between the intersection of the straight line extending perpendicularly to 21A and the surface of the hard carbon coating 5) is also set to 100 μm or less.

Accordingly, in the second reference example , as in the first reference example and the embodiment, it is possible to form a fine groove having a groove width of 100 μm or less on a workpiece made of a brittle material with high accuracy in a short time. It is possible to provide an inexpensive micro reaction system chip capable of highly accurate analysis. Furthermore, in the second reference example , the tip 21 has a frustum shape in which the outer diameter gradually increases toward the rear end as in the above-described embodiment. Since the tip of the tip 21 is a flat tip surface 21B similar to the tip surface 4B of the tip 4 of the first reference example , the tip 11B remains conical as in the above embodiment. Compared with the point portion 11 extending to one point, it is possible to prevent the tip portion 21 from being chipped at the most advanced portion and the deterioration of the molding accuracy of the cutting edge portion 6 associated therewith.

Moreover, the tip angle α of the peripheral surface 21A of the frustum-shaped pointed portion 21 is 60 ° or less, and the outer diameter e of the tip surface 21B is 33 μm or less. It becomes possible to succeed more reliably. That is, when the outer diameter e of the tip surface 21B is larger than 33 μm, a thickness t larger than the outer diameter e is secured on the hard carbon coating 5 as in the first reference example, and then the cutting edge portion 6 The outer diameter D may be difficult to be 100 μm or less, and if the tip angle α is larger than 60 °, the groove width is increased even if the cutting amount is slightly increased as in the above embodiment. As a result, there is a possibility that extremely fine processing becomes difficult. However, when the tip angle α and the outer diameter e are too small, for example, when the tip angle α is 0 °, the configuration is the same as in the first reference example , and when the outer diameter e is 0 μm, the above-described implementation is performed. Since it becomes the structure similar to a form, the above-mentioned effect by the front-end | tip part 21 having a frustum shape cannot be acquired. For this reason, it is desirable that the tip angle α formed by the peripheral surface 21A of the tip portion 21 is in a range of 10 to 60 °, and the outer diameter e of the tip surface 21B is in a range of 5 to 33 μm. desirable.

The first reference example tip 4 is a cylindrical shaft-like, in the above embodiment the tip portion 11 is conical, but tip 21 in the second reference example is a truncated cone shape, these other In the reference example, a prismatic shaft shape, a pyramid shape, or a truncated pyramid shape may be used, and a tip portion of the shaft may be a truncated cone shape or a truncated cone shape. FIG. 5 shows a cross-sectional view of the tip side portion of the third reference example having the frustum-shaped pointed portion 31 whose diameter is reduced toward the tip side at the tip portion of the shaft. Elements common to the first and second reference examples and the embodiment shown in FIG. 4 are also assigned the same reference numerals.

That is, in the third reference example , similarly to the first reference example , a small-diameter cylindrical shaft centered on the center line O is provided on the tip end side of the shank portion (not shown) of the tool body 1 via the conical portion. The tip of the cylindrical shaft is formed into a tapered regular hexagonal truncated pyramid centered on the center line O and is a pointed end 31. Therefore, the pointed portion 31 has a substantially regular hexagonal shape in a cross section perpendicular to the center line O, and the surface thereof has six inclined flat surfaces 31A gradually narrowing toward the tip side and these peripheral surfaces 31A. A regular hexagonal tip surface 31B perpendicular to the center line O intersecting the tip of the peripheral surface 31A is formed. The tip angle of the tip 31 (in the third reference example , as shown in FIG. 5, a pair of intersecting ridgelines 31C located on opposite sides of the centerline O among the intersecting ridgelines between adjacent peripheral surfaces 31A. Is preferably within the range of 10 to 60 °, 30 ° in the third reference example , and the outer diameter of the tip surface 31B (tip surface 31B in the third reference example). The diameter of the circle circumscribing the regular hexagon formed by E) is also preferably in the range of 5 to 33 μm, and is 30 μm in the third reference example .

A cutting edge portion 6 is formed on the surface of the tip portion 31 by coating the hard carbon coating 5 having a film thickness t larger than the outer diameter e of the tip surface 31B substantially uniformly. Therefore, the surface of the tip portion of the cutting edge portion 6 is formed to have a semi-oval shape with the axis O as the short axis in the cross section along the center line O, as in the first and second reference examples. In addition, in a cross section orthogonal to the axis O, a regular hexagonal frustum in which each corner portion of the regular hexagon formed by the cross section of the apex 31 is rounded and the cutting edge 6 is the same as the apex 31 is shown. It will be formed in a shape. It should be noted that the outer diameter D at the tip of the cutting edge portion 6 on which the hard carbon coating 5 is thus formed (in the third reference example , along the center line O including the pair of intersecting ridge lines 31C as shown in FIG. 5). In the cross section, the diameter between the intersection of the pair of intersecting ridgelines 31C and the tip end surface 31B and the straight line extending perpendicularly to each intersecting ridgeline 31C and the surface of the hard carbon coating 5) is also within a range of 100 μm or less. In the third reference example , the thickness is set to 70 μm, and the film thickness t of the hard carbon coating 5 is in the range of 5 to 50 μm after satisfying these ranges.

In the third reference example as well, it is possible to apply the same groove processing as the end mill with corner R or the radius end mill to a workpiece made of a brittle material, as well as a regular hexagon in which the tip 31 is a polygonal frustum. Since it is formed in the shape of a truncated pyramid, the cutting edge portion 6 whose surface is coated with the hard carbon coating 5 also exhibits a substantially regular hexagonal truncated pyramid as described above, and therefore this cutting edge portion 6 rotates. However, between the inner surfaces of grooves and the like formed on the surface of the workpiece by being fed out and the respective conical surfaces of the cutting edge portion 6, the central portion of the intersecting ridge line portions of the conical surfaces, that is, perpendicular to the center line O In the cross section to be cut, a space is provided at the center of each side of the substantially regular hexagon presented by the cutting edge 6. For this reason, the ultrafine chips generated by scraping off the workpiece with the ultrafine cutting edge by the hard carbon particles on the surface of the cutting edge portion 6 as described above at the time of machining, the inside of the groove or the like through the gap portion. Therefore, according to the third reference example , for example, such chips are caught between the cutting edge portion 6 and the groove inner surface and the groove on the surface of the workpiece is formed. It is possible to prevent edge breakage from occurring at the edge of the open groove, and it is possible to facilitate the processing of a high-precision and high-quality micro reaction system chip.

In the third reference example , the pointed portion 31 is formed in a truncated pyramid shape so that the cutting edge portion 6 also has a truncated pyramid shape. However, as described above, the pointed portion has a prismatic shaft shape or a truncated pyramid shape. However, since there is a space between the circumferential surface or the conical surface and the inner surface of the groove, the above-mentioned effect can be achieved. This is because the prism, the pyramid, or the truncated pyramid has a regular cross section. The same applies even if the shape is not square. However, if the cross section perpendicular to the center line O of the pointed portion or the cutting edge portion is not a regular polygon, there is a possibility that the gap is partially widened and the discharge of uniform chips is hindered. If the regular polygon is equal to or more than a regular hexagon, the interval may be reduced over the entire circumference, and the above-described effect may not be reliably achieved. On the other hand, if this cross section is a triangle, including at least one corner of the cross section, including the equilateral triangle, an acute angle is formed. Since the hard carbon film 5 of the cutting edge portion 6 coated with the tip is likely to be chipped or peeled off, when the pointed end portion 31 or the cutting edge portion 6 has a polygonal cross section, a positive four-diameter expansion (square), a positive A pentagon, regular hexagon, regular heptagon, and regular octagon are desirable.

Furthermore, in the above embodiment, the tip 11 may not be strictly conical, but the tip 11B may be rounded as long as it is within the range of the forming error . In the first to third reference examples, the tip surfaces 4B, 21B, 31B may be inclined. Further, since the surface of the cutting edge portion 6 formed by coating the tip portions 4, 11, 21, 31 with the hard carbon coating 5 is uneven as described above, the tip is strictly cross-sectionally half-sectioned. For example, the tip surface of the cutting edge portion 6 in the first to third reference examples may be slightly concave or convex, and this may be a convex shape. The tip of the cutting edge 6 may be slightly flattened in the direction of the center line O or in a direction perpendicular to the center line O as a whole.

On the other hand, in the processing method using the microfabrication tool according to the above embodiment and the first to third reference examples , a micro-reaction system chip having a fine width and a workpiece made of a brittle material such as a glass substrate or a ceramic substrate. Although the case where the groove of the depth is formed has been described, the cutting blade portion 6 is cut into the surface of the workpiece while rotating the tool body 1 around the center line O of the tip portions 4, 11, 21, 31, If the tool body 1 is moved forward in the direction of the center line O as it is, holes and recesses can be formed in the workpiece. At this time, according to the fine processing tool of the first reference example , if the tool main body 1 is advanced between the depth of the film thickness t after the cutting edge portion 6 is cut into the workpiece surface. When a concave portion is formed in which a concave curved wall surface having a circular arc shape having a radius t is formed from the outer circumference of the bottom of the circular bottom surface having a diameter d, the tool body 1 is advanced by a depth greater than the film thickness t. A straight hole having an inner diameter (diameter) D whose bottom forms the shape of the recess is formed.

Further, according to the fine processing tool of the above embodiment and the second and third reference examples , if the tool main body 1 is advanced to a depth where the diameter of the opening becomes the outer diameter D, the embodiment Then, a concave spherical concave portion having a radius t is formed, and in the second and third reference examples , a concave curved surface wall having a circular arc shape having a radius t is formed from the outer periphery of a circular bottom surface having a diameter e. According to these embodiments and the second and third reference examples , if the tool body 1 is advanced at a depth larger than this, the hole bottom forms the concave shape as described above, and the opening of the hole A tapered hole whose inner diameter gradually increases toward the portion with a taper angle corresponding to the tip angles θ and α can be formed. Of course, if the tool body 1 is advanced so that the cutting edge portion 6 penetrates the workpiece, the straight hole or the tapered through hole as described above can be formed.

DESCRIPTION OF SYMBOLS 1 Tool main body 4,11,21,31 Pointed part 4A Peripheral surface of the pointed part 4B Tip surface of the pointed part 4 5 Hard carbon coating 6 Cutting edge part 11A Conical surface of the pointed part 11B Projected end of the pointed part 11A 21A Pointed part 21B peripheral surface 21B tip surface 31A of the tip 21 31A cone surface 31B of the tip 31 31B tip 31C of the tip 31C intersecting ridge line between adjacent cones 31A O center line of the tool body 1 (points 4, 11, 21) , 31 centerline)
t The thickness of the hard carbon coating 5 D The outer diameter of the cutting edge portion 6 d The outer diameter of the tip portion 4 θ The tip angle of the tip portion 11 e The outer diameter of the tip surfaces 21B, 31B of the tip portions 21, 31 α The tip portion 21, 31 peripheral surface 21A, tip angle of 31A

Claims (5)

The tip portion formed on the tool body is coated with a hard carbon coating, and the thickness of the hard carbon coating is larger than the outer diameter at the tip of the tip portion, and the tip of the tip portion is formed by the hard carbon coating. A cutting edge portion having a substantially convex curved surface is formed at the tip, the pointed end is formed in a conical shape with a tip angle in the range of 10 to 60 °, and the surface of the cutting edge is the tip A tool for micromachining, characterized in that the tip of the part is formed in a substantially spherical shape having a center on the center line of the cone formed by the pointed part.   The micromachining tool according to claim 1, wherein the hard carbon film has a thickness in a range of 5 to 50 µm.   3. The micromachining tool according to claim 1, wherein an outer diameter of the cutting edge is in a range of 10 to 100 μm.   4. The micromachining tool according to claim 1, wherein the tip of the pointed portion is rounded. Using the micromachining tool according to any one of claims 1 to 4, the cutting blade portion is placed on the surface of a workpiece made of a brittle material while rotating the tool body around the center line of the tip portion. A microfabrication method for a brittle material, characterized by performing micromachining on the workpiece by cutting.

Images