Locally-coated drill point structure

Abstract

The utility model provides a local film-covered drill point structure, which comprises a drill body, a drill point is formed at the front end of the drill body, at least one spirally-wound edge strip and at least one spirally-wound chip groove extend backwards from the drill point, and a diamond film is attached to the at least one edge strip through a surface treatment technology. Therefore, the edge strip of the drill point is covered by the diamond film in the drilling process, the use durability is prolonged, and the effect of prolonging the service life of the drill point is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of local film's drill point structure, especially, a kind of diamond film is formed by surface treatment on the outermost blade surface of the outer diameter of drill point, and the durability of the blade of the drill point is extended by the coating of the diamond film during the process of drilling, and the service life of drill point is improved. BACKGROUND

[0002] In the basic mechanical working, in addition to lathe, bench worker, planer, milling machine and grinding machine and so on, drilling processing is also a very important process in mechanical processing. Many workpieces may need to be drilled during manufacturing process to produce necessary holes for use or further processing. Drill is a necessary tool during drilling operation. Drill bit is used to drill various forms of holes on workpiece to form through holes or blind holes. During drilling operation, two helical cutting edges of drill bit extend to two helical chip flutes with inclined chip surface on both sides to remove the waste generated during drilling process. This is a necessary structure on drill bit.

[0003] However, when general drill bit is used for cutting, the two cutting edges on the cutting end of drill bit contact with workpiece to perform cutting. Due to high-speed rotation of drill bit during cutting process, friction loss occurs between the two cutting edges on the cutting end of drill bit, helical chip flutes and workpiece, and high temperature is generated, which affects the quality of drill bit and shortens its service life.

[0004] In order to avoid the problem of wear and high temperature during cutting and improve the service life of drill bit, the prior art provides a processing method for coating the surface of drill bit with a layer of diamond film to effectively coat the surface of drill bit with diamond film.

[0005] However, although the processing method of directly coating drill bit with a layer of diamond film can prolong its service life, the thickness of the diamond film needs to be increased to ensure the continuity and integrity of the diamond film on the surface of drill bit according to the island mechanism of diamond growth (large diamond clusters are formed first, and then diamond films are connected between the diamond clusters). The high thickness of the diamond film (e.g. 8-12 μm) causes serious rounding of the cutting edge, which greatly reduces the cutting force of drill bit. In addition, the quality of the processed plate is difficult to meet the requirements due to insufficient cutting force, and the drill bit is easily broken due to excessive cutting resistance.

[0006] And when the cutting edge of the drill bit is worn and needs to be ground, the diamond film coated on the cutting edge has high hardness and large coating area, causing the diamond-coated drill bit to be unable to be ground, which is a key point that needs to be researched and improved by those skilled in the art. SUMMARY

[0007] Therefore, in view of the above problems and deficiencies, the main purpose of the present application is to provide a drill bit structure with partial film coating.

[0008] The drill bit structure with partial film coating provided by the present application comprises a drill body, characterized in that: a drill tip is formed at the front end of the drill body, and at least one spiral wrapping blade band and at least one spiral wrapping chip groove extend rearward from the drill tip, and the at least one blade band is attached with a diamond film after surface treatment.

[0009] The drill bit structure with partial film coating, wherein: the blade band is surface treated by surface cobalt removal.

[0010] The drill bit structure with partial film coating, wherein: the blade band is surface treated by surface attachment of a nitride film.

[0011] The drill bit structure with partial film coating, wherein: the blade band is grown with a diamond film by chemical vapor deposition technology.

[0012] The drill bit structure with partial film coating, wherein: the film layer thickness of the diamond film is between 0.1 µm and 10 µm, and the diamond grain is less than 1000 nm.

[0013] The drill bit structure with partial film coating, wherein: the film layer thickness of the diamond film is between 0.5 µm and 5.0 µm.

[0014] The drill bit structure with partial film coating, wherein: the diamond grain is less than 500 nm.

[0015] The drill bit structure with partial film coating, wherein: the outer diameter size of the drill bit is 0.075-0.6 mm.

[0016] The drill bit structure with partial film coating, wherein: the drill bit is made of tungsten steel.

[0017] The drill bit structure with partial film coating provided by the present application allows the blade band of the drill bit to be coated with the diamond film during drilling, thereby prolonging the durability of the drill bit and improving the service life of the drill bit. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a front view of the drill bit structure with partial film coating of the present application.

[0019] Figure 2 The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0020] Figure 3 The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0021] Figure 4 The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0022] Figure 5 The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0023] Figure 6 The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0024] Figure 7 The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0025] Figure 8 The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0026] The partial film-coated drill bit structure is a partial film-coated drill bit structure. DETAILED DESCRIPTION

[0027] Please refer to Figures 1 to 3 The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0028] The partial film-coated drill bit structure is a partial film-coated drill bit structure.

[0029] Furthermore, in actual application, the drill needle 1 is processed after surface treatment of the semi-finished product (not shown in the figure) of the drill needle 1, and then the blade 112 on the outermost side of the outer diameter of the drill needle 1 is surface treated after processing. The blade 112 is formed by chemical vapor deposition (CVD) technology, and the diamond film 2 is attached to the surface of the blade 112 with an arc. When the drill needle 1 is used for drilling the workpiece 3, the blade 112 of the drill needle 1 contacting the hole wall of the workpiece 3 is protected by the diamond film 2, and the service life is prolonged by nearly 10 times. Since the drill tip 111 and the cutting surface 1111 are not covered by the diamond film 2, the drill tip 111 and the cutting surface 1111 are not affected by the diamond film 2 during drilling, and the cutting force is reduced. After the drill tip 111 and the cutting surface 1111 are worn, they can be directly re-ground (polished) to increase the number of uses of the drill needle 1.

[0030] The outer diameter of the drill needle 1 is 0.075-0.6 mm, and the tungsten steel material of the drill needle 1 is a combination of tungsten steel and cobalt as the main component, wherein the tungsten carbide particle size is 0.2-2.0 μm, and the cobalt content is 3%-10% wt%.

[0031] The workpiece 3 is an electronic circuit substrate or a semiconductor packaging substrate.

[0032] The drill needle 1 is surface treated by two-stage pre-treatment, and diamond film plating is performed after the two-stage pre-treatment.

[0033] The first stage of pre-treatment inhibits cobalt in the drill needle to avoid catalyzing diamond into graphite during diamond film plating at high temperature. The pre-treatment method for inhibiting cobalt can be divided into two types:

[0034] 1. Chemical etching method: using chemical agents to remove the binder cobalt in the drill needle.

[0035] 2. Interlayer method: using a nitrogenized ceramic film as an interlayer to be plated on the drill needle first, and then diamond film plating is performed. (Cobalt diffuses to the surface of the drill needle due to high temperature during diamond film plating.)

[0036] The second stage of pre-treatment is to use ultrasonic oscillation when the drill needle is seeded with diamond crystals to make the diamond crystals more effectively embedded on the surface of the drill needle, thereby improving the density of the seed nucleus, and then using a chemical vapor deposition process to make the low-thickness diamond film grow from a discontinuous island into a continuous film, and the adhesion of the diamond film is improved due to the increased density of the seed crystal embedding.

[0037] The diamond film coated drill bit has high hardness and large film coating area, so after drilling, it is difficult to use a grinding wheel to grind and sharpen the cutting edge of the drill bit again, thereby greatly reducing the service life of the drill bit (only one-time processing of a needle).

[0038] Furthermore, by developing a new type of PCB diamond coated drill bit process flow, when the white knife finished product drill bit is coated with diamond film, only the outermost drill diameter & cutting edge is locally and continuously coated with a thin diamond film (0.1 μm< film thickness <10.0 μm), and the diamond grain is less than 500 nm.

[0039] In addition, by developing a selected area diamond coated drill bit, the rigidity of the diamond coated drill bit can be improved, and the problem of low hole number breakage of small diameter diamond coated drill bits (<Φ0.25 mm) (abnormal breakage of less than 100 holes) can be overcome.

[0040] Using a thin film layer (film thickness <8.0 μm), the cutting edge of a small diameter selected area diamond coated drill bit (<Φ0.25 mm) maintains high cutting force (excessive thickness of the film layer will cause the cutting edge to form a rounded corner), and by virtue of the high hardness (~10,000 HV, more than 2.5 times better than common nitride ceramic film), high heat dissipation characteristics (~2000 Wm−1K−1, 6 times better than copper), and low friction coefficient (<0.2, 50% better than common nitride ceramic film) of the diamond thin film 2, the cutting resistance of the selected area diamond coated drill bit during drilling is reduced, and the excellent physical properties of the diamond film layer improve the quality of the processed board (hole accuracy, hole roughness, nail head, Burr…).

[0041] Please refer to Figure 4 The film coating method of the local film coating drill bit is implemented according to the following steps, wherein:

[0042] (A01) The semi-finished product of the drill bit 1 is subjected to first stage surface treatment to inhibit the catalysis of cobalt in the tungsten steel drill bit of the semi-finished product of the drill bit 1 into graphite during diamond coating;

[0043] (A02) The semi-finished product of the drill bit 1 is subjected to subsequent processing procedures to complete the manufacture of the drill bit 1;

[0044] (A03) The finished drill bit 1 is subjected to a second stage surface treatment, so that the diamond seeds in the drill bit 1 are implanted in combination with ultrasonic oscillation, so that the adhesion of the diamond film 2 can be improved after the diamond film 2 is formed;

[0045] (A04) The diamond film 2 is grown on the outermost blade 112 of the drill bit 1 by chemical vapor deposition technology;

[0046] (A05) The film coating process of the blade surface of the drill bit is completed.

[0047] The surface treatment in the step (A01) is a surface cobalt removal process of the drill bit 1, which assists the growth of the film.

[0048] The surface treatment in the step (A01) is a two-stage pre-treatment of the drill bit 1, the first stage pre-treatment removes cobalt in the tungsten steel drill bit, which assists the growth of the film.

[0049] The second stage pre-treatment in the step (A03) implants the diamond seeds in combination with ultrasonic oscillation, so that the diamond seeds can be more effectively embedded on the surface of the drill bit 1, the implantation density is improved, and the low-thickness diamond film is grown from discontinuous islands to continuous film by chemical vapor deposition process, and the adhesion of the diamond film 2 is improved due to the improved implantation density of the seeds.

[0050] In addition, please continue to refer to Figure 5 , Figure 7 , which are respectively a second embodiment of the coated drill bit structure of the utility model, and the front view and side view of the coated drill bit structure of the utility model can be clearly seen from the drawings. Figure 1 , Figure 2 The difference between the two is that Figure 5 The drill bit 1 of the coated drill bit structure of the utility model does not have a clearance, which is a simple and equivalent change and modification, and does not limit the protection scope of the utility model, and Figure 5 The disclosed remaining structure is the same as Figure 1 , Figure 2 Therefore, it will not be repeated here.

[0051] Furthermore, please continue to refer to Figure 6 , Figure 8 , which are respectively a third embodiment of the coated drill bit structure of the utility model, and the front view and side view of the coated drill bit structure of the utility model can be clearly seen from the drawings. Figure 6 The third embodiment of the coated drill bit structure of the utility model is a single-blade drill bit 1 formed by a single blade 112, which is a simple and equivalent change and modification, and does not limit the protection scope of the utility model, and Figure 1 The disclosed remaining structure is the same as Figure 2 Therefore, it will not be repeated here.

[0052] And the above-mentioned partial film coating drill needle and its film coating method have the following advantages:

[0053] (I) The surface of the outermost blade band 112 of the drill needle 1 is coated with the diamond film 2, which increases the durability of the blade band 112 on the hole wall of the workpiece 3 during cutting, thereby increasing the service life of the drill needle 1.

[0054] (II) The drill needle 1 is only coated with the diamond film 2 on the surface of the blade band 112, so that the drill point 111 and the cutting surface 1111 can be directly ground after being worn during drilling, thereby improving the overall service life of the drill needle 1.

[0055] The above is only a preferred embodiment of the partial film coating drill needle structure of the present application, and is not limited to the patent scope of the present application. Therefore, any simple modification and equivalent structural change based on the content of the present application specification and drawings should also be included in the patent scope of the present application.

Claims

1. A locally coated drill bit construction comprising a drill body, characterised in that: The drill body has a drill tip at the front end, and at least one spiral-wound blade and at least one spiral-wound chip flute extend rearward from the drill tip, and the at least one blade has a diamond film attached via surface treatment technology, wherein the diamond film is formed only on the outermost blade surface of the drill needle.

2. The partially coated drill bit construction of claim 1 wherein: The blade is surface-treated by surface cobalt removal.

3. The partially coated drill bit construction of claim 1 wherein: The blade is surface-treated by surface attachment of a nitride film.

4. The partially coated drill bit construction of claim 1 wherein: The blade is surface-treated by chemical vapor deposition technology to grow the diamond film.

5. The partially coated drill bit construction of claim 1 wherein: The diamond film has a film thickness of 0.1 µm~10 µm, and the diamond grain is less than 1000 nm.

6. The partially coated drill bit construction of claim 1 wherein: The diamond film has a film thickness of 0.5~5.0µm.

7. The partially coated drill bit construction of claim 1 wherein: The diamond grain is less than 500 nm.

8. The partially coated drill bit construction of claim 1 wherein: The drill needle has an outer diameter of 0.075~0.6 mm.

9. The partially coated drill bit construction of claim 8 wherein: The drill needle is made of tungsten steel.

Images