JP4348583B2 - Diamond drill and manufacturing method thereof - Google Patents

Description

[0001]
[Industrial application fields]
TECHNICAL FIELD The present invention relates to a precision cutting tool used for extremely small-diameter hole drilling technology, and more specifically, to a hard-to-machine hard material such as a super hard material, a silicon single crystal material, and a ceramic material. The present invention relates to a top solid type diamond drill for performing a dawn process.
[0002]
[Prior art and problems]
Conventionally, in this type of cutting tool for hard materials, in metal processing, titanium carbide / nitriding such as TiC, TiN, etc. on the surface of the drill region of a drill base material made of a metal material having a general spiral groove In the processing of glass, ceramics, etc., diamond abrasive grains are electrodeposited and applied to the surface of a metal tool, and a hard film of DLC (diamond-like carbon) formed by a film forming method such as ion plating. Alternatively, a diamond tool in which diamond abrasive grains are baked and hardened on a metal tool surface with a resin or the like to form a grindstone portion (hereinafter, a diamond tool having diamond abrasive grains fixed to the metal tool surface is referred to as a diamond tool).
[0003]
A common problem required for these various cutting tools is to first improve the wear resistance, that is, to extend the life of the tip life cycle. The most representative one improved for that purpose is a “diamond drill” that can be used for various applications regardless of the material of the workpiece.
[0004]
This is used as a drill shape by attaching a sintered chip of polycrystalline diamond to a cutting tool cutting edge portion of a drill base material made of a metal material. As a result, the diamond drill using the polycrystalline sintered diamond as a cutting tool for drilling silicon, carbon, ceramics, etc. due to the excellent characteristics such as hardness, wear resistance, and thermal conductivity of the polycrystalline sintered diamond. Is attracting attention.
[0005]
Generally, the diamond drill is effective not only for drilling light alloys such as aluminum as a cutting tool but also for composite materials such as glass, epoxy resin, and printed circuit boards. Developed exclusively for drilling holes in difficult-to-work materials such as cemented carbide, sapphire single crystal, zirconia ceramics, etc., so-called polycrystalline sintered diamond chips are attached to the tip. The “top solid diamond drill” was gradually put into practical use and is now in use.
[0006]
More recently, with the demand for micro-machining technology for ultra-precision parts indispensable for etching equipment used in semiconductor manufacturing processes, the demand for drills for ultra-fine diameter drilling with higher precision, higher speed, and longer life has increased. It is also being applied to difficult-to-work materials such as silicon electrode plate parts of the etching apparatus.
[0007]
However, at present, when the thickness of a substrate such as a silicon electrode plate is 10 mm or more, the main spindle tool side to be machined, such as the top solid diamond drill with a shank currently on the market shown in FIG. The drill length (L dimension of the drilling effective portion) is short, the length is insufficient, and the deep hole machining dimension is limited.
[0008]
Especially in the case of top solid diamond drills with a hole diameter of about φ0.30mm to φ0.60mm, in the manufacturing process of polycrystalline sintered diamond, the drill length is The L dimension was limited to a length of about 7 mm including the sintered diamond 81 portion and the base metal portion 82.
[0009]
[Means for Solving the Problems]
In response to the above-mentioned problem of the diamond drill for processing ultrafine deep holes and the problems in the prior art, the diamond powder green compact is laminated on the green compact base material of the cemented carbide material, and this is subjected to high temperature and high pressure. When the substrate is cut into a lattice shape as a material removal from the formed integrally sintered substrate, at least a polycrystalline sintered substrate is manufactured. A pair of cuts facing each other by obliquely cutting in the thickness direction with an arbitrary inclination angle of θ = 30 ° to 85 ° in the blade direction on one of the X and Y axis directions on the surface of the diamond substrate An elongated rod-shaped diamond drill forming blank with parallel surfaces is obtained, and an elongated long type top solid diamond drill with a drill length (L dimension) of 7 mm or more is manufactured using this elongated rod-shaped blank material. It is intended.
[0010]
At this time, when cutting the substrate obtained by the manufacturing process of polycrystalline diamond by integral sintering with the cemented carbide in a lattice shape, it is possible to obliquely cut the thickness direction with an inclination angle in the cutting blade direction, Finally, the drill length (L dimension) is determined. In other words, the sintered material substrate is not simply cut in a direction perpendicular to the substrate plane, but at least in one of the X and Y axis directions of the substrate surface as an insertion angle with respect to the substrate plane, θ = By giving an arbitrary inclination angle of 30 ° to 85 ° and obliquely cutting the thickness direction, assuming that the thickness of the substrate is t, the drill length (L dimension) is an elongated rod shape with L = t / Cosθ A diamond drill compact blank can be obtained.
[0011]
However, when the inclination angle is θ = 30 ° or less, the contribution effect to the drill length (L dimension) by oblique cutting can hardly be expected, and when θ = 85 ° or more, the ultrafine diameter of φ0.3 mm This is not preferable because the material strength of the cemented carbide cutting tool may be insufficient.
[0012]
By externally processing the drill molded body blank, the external shape of the thin rod-shaped drill having polycrystalline sintered diamond at the tip is, for example, a pyramidal or multi-step tip angle at the tip of the drill. It has a substantially bullet-shaped pyramid shape, and the integrally sintered metal base is a polygonal prism that is longer than a long triangular prism, and as another example, has a spiral groove and a land, and these are spiral These elongated long types, such as those with a sintered diamond tip at the tip, which is drilled with a cylindrical side groove with a twist angle and the tip edge is processed into a straight or undercut type shape with a tip angle, etc. A top solid diamond drill can be easily manufactured.
[0013]
In addition, instead of the polycrystalline sintered diamond material, polycrystalline cubic boron nitride (PCBN sintered body) is used as a hard material to be sintered integrally with cemented carbide, and the same top solid is drilled. A drill may be created, and a base material composition such as cemented carbide suitable for integral sintering may be changed and combined within a range not departing from the gist of the present invention.
[0014]
[Example 1]
Hereinafter, an embodiment of the production process of the present invention will be described with reference to the drawings.
The disk shape shown in FIG. 5 (a) is a polycrystalline sintered diamond substrate obtained by cemented cemented carbide integrated sintering, and the diamond powder pressure is applied on the powdered compact substrate of cemented carbide (WC). The powders are stacked and processed under high temperature and high pressure to obtain an integrally sintered material substrate 50. The formed integrally sintered material substrate 50 has an outer diameter of about 60 mm and a thickness direction of about 7 mm including the sintered diamond layer 51 and the cemented carbide layer 52.
[0015]
Next, as shown in FIG. 5 (b), the integrally sintered material substrate 50 is finely cut into a lattice shape in order to remove the material of the thin rod-shaped drill. At this time, at least one of the X and Y axis directions on the surface of the polycrystalline sintered diamond substrate is provided with an arbitrary inclination angle θ of 30 ° to 85 °, and the thickness direction is cut obliquely. .
[0016]
As a result, it is divided into individual ones as shown in FIG. 1C, and is formed into a thin rod shape as shown in FIG. Is obtained.
[0017]
More specifically, for example, as shown in FIG. 6, when the board thickness is about t = 7 mm and the cutting inclination angle of the cutting is θ = 55 °, a drill effective as a drill forming blank 106 is used. The length (L dimension) is about 12 mm including the cutting loss. Similarly, if the inclination angle is θ = 70 °, L = about 20 mm, and the conventional drill length (L dimension). It becomes possible to take a molding blank of a long size close to three times the limit length.
[0018]
Next, an example of producing a square pillar type diamond drill using this elongated rod-shaped drill forming blank will be described. First, the cut long and narrow rod-shaped blank is prepared by grinding / polishing to the shape of each side to be a regular square column, and the tip of the polycrystalline sintered diamond side has the multi-step tip angle shown in FIG. The diamond drill main shaft portion 10 is formed by processing into a substantially shell shape having the same.
[0019]
By fixing this to the end of the cylindrical metal shank 5 by brazing, a long solid top solid diamond drill 20 having a drill length (L dimension) of about 20 mm and having the appearance shown in FIG. 2 is completed.
[0020]
FIG. 1 shown here is an enlarged perspective view of the tip portion of a diamond drill in one embodiment of the present invention, wherein 1 is a polycrystalline sintered diamond portion, and 2 is a metal base of a prismatic drill main portion. Cemented carbide (tungsten carbide: WC) part, 3 is a joint boundary line by integral sintering, 4 is a substantially bullet-shaped pyramid part with multi-stage tip angle that becomes the cutting edge part of the drill tip, FIG. 2 is a schematic perspective view of a finished product of the diamond drill 20 in which the sintered body is brazed and fixed to five metal shank parts that are actually used for drilling.
[0021]
Further, the finished product of the diamond drill 20 in FIG. 2 is L = about 20 mm when the drill length (L dimension) of the main part 10 of the diamond drill is θ = 70 °, and this diamond drill 20 is used. By drilling the pores, it becomes possible to perform deep hole machining more than twice the limit length of the conventional drill length (L dimension).
[0022]
[Example 2]
Next, a process of creating a diamond drill having another external shape using an elongated rod-shaped diamond drill forming blank obtained by the same substrate cutting process as in Example 1 will be described. Here, description of the contents related to the substrate manufacturing is omitted, but as described above, as shown in FIG. 7, the cutting inclination angle of cutting is θ = 75 °, and the effective drill length as a drill forming base material is L = A molding blank 107 having a size of about 25 mm is obtained by cutting.
[0023]
An example of manufacturing a diamond drill with a spiral groove using this elongated rod-shaped drill forming blank 107 is shown below. First, the cut elongated rod-shaped drill-shaped blank 107 is prepared such that each diagonal portion is formed into a cylindrical shape by grinding, polishing, electric discharge machining or the like so as to be a perfect circular cylinder, and further, the tip of polycrystalline sintered diamond 3 is processed into a drill shape with a spiral groove to create a diamond drill spindle 30 shown in FIG.
[0024]
As a result, as shown in the hexahedral view of FIG. 3, the external shape of the thin rod-shaped drill having polycrystalline sintered diamond at the tip portion has a spiral groove portion 34 and a land portion 35 , and these are spiral twists. become drill shape with cylindrical side surface groove having a square, the polycrystalline sintered diamond 31 of the distal cutting edge, it is also possible to add the processed leading cutting edge shape straight or undercut type shape having a tip angle It is.
[0025]
This is fixed to the end of the cylindrical metal shank by brazing, so that a top solid diamond drill 40 with a spiral groove of a long and ultra long type with a drill length (L dimension) of 20 mm or more is shown in Fig. 4. Is completed.
[0026]
FIG. 3 shown here is an enlarged hexahedral view of a diamond drill blade tip portion in another embodiment of the present invention, 31 is a polycrystalline sintered diamond portion, and 32 is a metal base of a cylindrical drill main portion. Cemented carbide (tungsten carbide: WC) part as a material, 33 is a joint boundary line by integral sintering, 36 is a tip processed into a straight or undercut type shape with a tip angle serving as a drill tip FIG. 4 shows a schematic side view of a finished product of a top solid diamond drill 40 in which a drill main shaft portion 30 of the sintered body is brazed and fixed to five metal shank parts actually used for processing. Is.
[0027]
Further, in the drilling using the diamond drill 40 having a diameter of 0.3 mm which is actually completed, the metal shank 5 shown in FIG. 4 is attached to the collet chuck pedestal of the rotary shaft on the drilling machine side, and the processing machine side The centering position of the center of rotation is adjusted, and about 2000 holes are drilled continuously in the center of the substrate of silicon single crystal (100) surface, 100mm square x 16.0mm thickness as a processed sample, and evaluated. went.
[0028]
As a result of measuring and evaluating the silicon single crystal substrate after the drilling process was completed, each of the first to 1000th processed hole diameters was measured. As a result, the 100th, 200th, and 300th positions from the initial 1st hole diameter were measured. , ... The change in the hole diameter at the 100th interval of the 900th and 1000th is within the size variation range of the set value ± 1 μm or less in the dimensional tolerance, and the hole diameter and shape from the 1000th to the 2000th are also greatly changed Was not seen, and the state of the hole was stable until the end. At the same time, there was no significant change in the shape and diameter of the drill tip at the diamond drill tip, and stable drilling performance was maintained until the end.
[0029]
【The invention's effect】
As described above, in the method of manufacturing an integrally sintered diamond drill according to the present invention (Claim 6), the diamond powder compact is laminated on the compact base material of the cemented carbide material. Is processed under high temperature and high pressure to produce a cemented carbide integrated sintered type polycrystalline diamond substrate, and as a material removal from the formed integrally sintered substrate, at least when the substrate is cut into a lattice shape, A pair of opposing surfaces by obliquely cutting in the thickness direction with an arbitrary inclination angle of θ = 30 ° to 85 ° in the insertion direction on either one of the X and Y axis directions of the surface of the crystal sintered diamond substrate An elongated rod-shaped diamond drill molding blank having a parallel cutting plane is formed, and the outer shape of the diamond drill is formed using the elongated rod-shaped molding blank material, so that the drill length (L dimension) is 10 mm or more. , It is possible to obtain a top solid diamond drill of unprecedented long size.
[0030]
In the diamond drill of the present invention (Claim 1), the diamond tip of the polycrystalline sintered diamond in the top solid diamond drill by cemented carbide cemented sintering in which the polycrystalline sintered diamond is arranged at the tip of the cutting drill. Joint surface with the integrally sintered metal base, where the section is divided from the drill tip to the bottom of the drill neck (to the other end of the center axis of the drill diameter) and with an angle of inclination with respect to the center axis Thus, it is possible to provide a long-sized diamond drill in which an oblique region portion is disposed at an intermediate portion of the drill length extending from the drill tip to the joint surface in the neck-down direction.
[0031]
Further, in the diamond drill of the present invention (Claim 2), the external shape of the thin rod-shaped drill having polycrystalline sintered diamond at the tip is a substantially bullet-shaped pyramid having a drill tip or a multi-step tip angle at the tip of the drill. It is possible to provide a long-sized diamond drill that has a shape and a monolithic sintered metal base material that is a polygonal column that is equal to or more than an elongated triangular column.
[0032]
Further, in the diamond drill of the present invention (Claim 3), the external shape of the thin rod-shaped drill having polycrystalline sintered diamond at the tip is a drill shape with a cylindrical groove having a spiral groove portion and a land portion and a helix angle. In addition, it is possible to provide a long-sized diamond drill having a sintered diamond tip processed into a straight or undercut type shape or the like having a tip angle at the tip edge.
[0034]
In addition, the present invention is a special precision cutting tool used in the above-described extremely small-diameter hole drilling technology, such as super hard materials, silicon single crystal materials, and hard-to-machine hard materials such as ceramic materials. It is possible to provide a long and thin diamond drill for drilling a large number of holes, and a top solid diamond drill with excellent cost performance and wear resistance can be realized.
[Brief description of the drawings]
FIG. 1 is an enlarged perspective view of a tip portion showing an example of a diamond drill according to the present invention.
FIG. 2 is a schematic external view showing an example of how the diamond drill is used in the present invention.
FIG. 3 is an enlarged six-side view of a tip portion showing another example of a diamond drill according to the present invention.
FIG. 4 is a schematic external view showing another example of how the diamond drill is used in the present invention.
FIG. 5 is a schematic diagram for explaining a part of the manufacturing process of the diamond drill in the present invention.
FIG. 6 is a schematic diagram for explaining a cutting process in manufacturing a diamond drill according to the present invention.
FIG. 7 is a schematic diagram for explaining a cutting step in manufacturing a diamond drill according to the present invention.
FIG. 8 is a side view showing an example of a conventional top solid type diamond drill having a spiral groove shape.
[Explanation of symbols]
1, 31, 51, 81 Polycrystalline sintered diamond
2, 32, 52, 82 Cemented carbide
3, 33, 53, 83 junction boundary
4, 36 Cutting edge
5 Shank
34 Groove
35 Land
105, 106, 107 Drilling blank

Claims (5)

  In a top solid diamond drill with cemented carbide cemented with polycrystalline sintered diamond at the tip of the cutting drill, the diamond tip of the polycrystalline sintered diamond moves from the drill tip to the drill neck (drill diameter). In the direction of the other end of the central axis of the drill) and the joint from the tip of the drill to the neck down from the joint surface with the integrally sintered metal substrate divided by a cut surface having an inclination angle with respect to the central axis. A diamond drill characterized in that a diagonal mixed region is placed in the middle of the drill length across the surface.   The external shape of a thin rod-shaped drill with polycrystalline sintered diamond at the tip is a pyramid shape with a drill tip or multi-step tip angle at the tip of the drill, and an integrally sintered metal base is elongated. The diamond drill according to claim 1, wherein the diamond drill is a polygonal cylinder having a triangular prism or more. The external shape of the thin rod-shaped drill having polycrystalline sintered diamond at the tip is a drill shape with a cylindrical side groove having a spiral groove and a land , and having a helical twist angle, and the tip of the tip 2. The diamond drill according to claim 1, wherein the portion is a sintered diamond tip processed into a straight or undercut type shape having a tip angle. The diamond drill according to any one of claims 1 to 4, wherein sintered boron nitride is used instead of the polycrystalline sintered diamond material. A diamond powder compact is laminated on a cemented carbide substrate, and this is processed under high temperature and pressure to produce a cemented carbide integrated sintered polycrystalline diamond substrate. Further, as material removal from the integrally sintered substrate, when the substrate is cut into a lattice shape, at least one of the X and Y axis directions of the polycrystalline sintered diamond substrate surface is θ = 30 ° in the insertion direction. An elongated rod-shaped diamond drill forming blank in which a pair of opposed cut surfaces are parallel is obtained by obliquely cutting the thickness direction with an arbitrary inclination angle of ˜85 °, and this elongated rod-shaped processing blank material A method for producing a diamond drill, comprising: forming an external shape according to any one of claims 1 to 4 of a top solid diamond drill.

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