CN101230459A - Micro-drill needle surface electroplating method and structure thereof - Google Patents

Abstract

The invention relates to a micro drill point surface electroplating method and a structure thereof, which comprises the following steps: a) providing a micro-drilling needle and a vacuum cavity, and placing the micro-drilling needle in the vacuum cavity; b) depositing the surface of the micro-drill point in an arc deposition mode to form a first coating layer; c) and depositing the surface of the first coating layer in a sputtering deposition mode to form a second coating layer. Therefore, the micro-drill needle has the mechanical properties of high hardness, low friction coefficient and high stability, and has the characteristics of wear resistance and improvement on processing precision.

Description

Surface electroplating method and structure of micro-drill needle

technical field

The invention relates to cutting tools, in particular to a micro-drill surface electroplating method and its structure.

Background technique

Generally, the drill can be divided into a shank and a blade, the shank is used for mechanical clamping of the tool, and the blade is used for processing the workpiece. Since the cutting edge is the main part of the drilling process, it must have mechanical properties with higher hardness than the workpiece in order to achieve the purpose of smooth processing.

In order to improve the mechanical properties of the drill, a known method is to coat the surface of the drill with a film with a higher hardness by arc deposition, so as to increase the hardness of the surface of the drill edge. However, if the film is coated by arc deposition, it is easy to generate metal droplets on the surface of the coating, which makes the surface of the coating uneven. Among them, the size of the metal droplet is about 0.7 μm to 2 μm. For the general drill, due to its large blade diameter and low precision requirements for drilling, the metal droplet is very important for the drill of the general drill. The precision of the hole is less affected, and the influence on the friction coefficient is not significant, so the influence caused by the metal droplet is still within the allowable range. However, if the micro drill (micro drill) is also coated by arc deposition, the hardness of the surface of the micro drill can also be improved. However, because the blade diameter is less than 3.175mm, and the drilling precision is required to be high; the metal droplet is too large, which not only greatly reduces the precision, but also greatly increases the impact on the friction coefficient of the drill. Therefore, the conventional method of coating by arc deposition is not suitable for micro drills.

In order to improve the above problems, sputter deposition is generally used for coating, which can make the film thickness of the coating more uniform without forming metal droplets, and the surface of the coating is relatively smooth. Compared with arc deposition, it can reduce the friction coefficient and improve the precision and speed of drilling. However, before coating by sputtering deposition, if an under-layer with high adhesion is not prepared on the surface of the drill bit as a substrate, such as: titanium nitride (TiN), the coating will be damaged. The problem of insufficient adhesion and easier peeling occurs. This type of microdrill has a short service life and cannot effectively achieve the purpose of improving the mechanical properties of the microdrill. It has the disadvantage of poor mechanical properties and needs to be improved.

To sum up, the conventional method of coating the surface of micro-drills has the above-mentioned shortcomings and needs to be improved.

Contents of the invention

The main purpose of the present invention is to provide a micro-drill surface electroplating method and its structure, which have the characteristics of wear resistance and improved processing accuracy.

In order to achieve the above object, a method for electroplating the surface of a micro-drill provided by the present invention is characterized in that it comprises the following steps: a) providing a micro-drill and a vacuum chamber, placing the micro-drill in the vacuum In the cavity; b) depositing the surface of the micro drill by arc deposition to form a first coating layer; c) depositing the surface of the first coating layer by sputtering deposition to form a second coating layer.

In the above-mentioned technical solution of the present invention, the micro-drilling needle in step a) is placed in the vacuum chamber after removing surface oil stains and drying water by ultrasonic waves in advance.

In the above-mentioned technical solution of the present invention, the vacuum chamber in step a) has a vacuum pipeline for pumping the vacuum chamber into a vacuum state.

In the above-mentioned technical solution of the present invention, the vacuum chamber in step a) is evacuated to 8×10 ^-3 Pa.

In the above-mentioned technical solution of the present invention, the arc deposition method mentioned in step b) is rotary arc deposition.

In the above-mentioned technical solution of the present invention, the thickness of the first coating layer in step b) is less than 3 μm.

In the above-mentioned technical solution of the present invention, the sputtering deposition method mentioned in step c) is unbalanced magnetron sputtering deposition.

In the above technical solution of the present invention, the second coating layer in step c) is deposited by sputtering with a non-conductive target.

In the above-mentioned technical solution of the present invention, the non-conductive target mentioned in step c) is selected from one of titanium diboride, aluminum oxide and boron nitride.

In the above-mentioned technical solution of the present invention, the thickness of the second coating layer in step c) is less than 3 μm.

A film obtained by the electroplating method according to claim 1, characterized in that it comprises: a micro-drill; a first coating layer formed on the surface of the micro-drill by arc deposition; a second coating layer , formed on the surface of the first coating layer by sputtering deposition.

The thickness of the first coating layer is below 3 μm.

The thickness of the second coating layer is below 3 μm.

The second coating layer is an alloy with a carbon base, a boron base, a nitrogen base or a titanium base.

By adopting the above technical scheme, the present invention first provides the mechanical properties of high hardness of the micro-drill blade by arc deposition, so that it has the characteristics of wear resistance, and then provides the micro-drill blade by sputtering deposition to form a smooth surface, which can Reduces the formation of rough surfaces and features a low coefficient of friction. Therefore, compared with the conventional coating method, the present invention can overcome the shortcomings of arc deposition coating surface roughness and sputtering deposition coating adhesion, and further improve the mechanical properties of the micro-drill blade, so that the micro-drill has a higher stability and long service life. Therefore, the present invention can overcome the disadvantages of conventional micro-drills, provide micro-drills with high hardness, low friction coefficient, and high stability mechanical properties, and have the characteristics of wear resistance and improved processing accuracy.

Description of drawings

Fig. 1 is a coating flow chart of a preferred embodiment of the present invention;

Fig. 2 is the front view of the microdrill needle of a preferred embodiment of the present invention;

Fig. 3 is a processing schematic diagram of a preferred embodiment of the present invention, which reveals the structure of the vacuum chamber;

Figure 4 is a partial enlarged view of a preferred embodiment of the present invention, which reveals the state of the micro-drilling needle blade surface before coating;

Fig. 5 is a schematic structural view of a preferred embodiment of the present invention, which reveals the state of the micro-drilling needle blade surface after arc deposition treatment;

FIG. 6 is a schematic structural view of a preferred embodiment of the present invention, which reveals the state of the micro-drill blade surface after sputtering deposition.

Detailed ways

In order to illustrate the structure and the achieved effects of the present invention in detail, the following preferred embodiments are given below together with the accompanying drawings.

As shown in Figures 1 to 6, it is a preferred embodiment of a micro-drill surface electroplating method and its structure provided by the present invention, and its coating program is as follows:

a) First, a micro drill 10 and a vacuum chamber 20 are provided, and the micro drill 10 is placed in the vacuum chamber 20 (as shown in FIG. 3 ). Wherein, the micro-drill 10 has a handle 12 and a blade 14 . Before the micro-drilling needle 10 is placed into the vacuum chamber 20, the surface oil is removed by ultrasonic waves in advance, so as to improve the adhesion of ions during deposition. Then dry the moisture attached to the microdrill 10 to prevent the formation of oxides when the microdrill 10 is deposited, and form protrusions on the surface of the microdrill 10 . The vacuum chamber 20 has a vacuum pipeline 22 for pumping the vacuum chamber 20 into a vacuum state of 8×10 ⁻³ Pa.

b) Depositing the surface of the micro-drill 10 by means of arc deposition to form a first coating layer 30. The arc deposition methods include cathodic arc deposition, filtered cathodic arc deposition and rotating arc deposition. Among the above-mentioned arc deposition methods, the hardness of the film formed by rotary arc deposition is better. Therefore, the arc deposition method of the present embodiment uses rotary arc deposition as an example, and conducts arc deposition on the surface of the microdrill 10 with a conductive target to form the first coating layer 30 (as shown in FIG. 5 ). The thickness of the first coating layer 30 is 3 μm. Wherein it can be foreseen that the first coating layer 30 will have several metal droplets forming protrusions on the surface. In terms of rotary arc deposition, the size of the formed metal droplets is just within the allowable range of the micro drill. Upper limit.

c) performing sputter deposition on the surface of the first coating layer 30 by means of sputter deposition to form a second coating layer 40 . Sputtering deposition methods include DC-diode Sputtering, magnetron sputtering, unbalanced magnetron sputtering, high frequency sputtering (ratio-frequency sputtering) and reaction Reactive gas sputtering deposition (reactive gas sputtering). In the above sputtering deposition method, due to the long working distance of the unbalanced magnetron sputtering deposition, the target material is relatively uniform during the sputtering deposition, thereby enabling the coating to form a relatively smooth surface. Furthermore, when the unbalanced magnetron sputtering deposition method is used for sputtering deposition, it is not limited to the applicable types of conductive targets and non-conductive targets, and has good applicability. Therefore, unbalanced magnetron sputtering deposition is used as an example for the sputtering deposition method in this embodiment. Among the target types, the hardness of the non-conductive target is the best, and the first three types of hardness from high to low are titanium diboride (TiB ₂ ), boron nitride (BN) and trioxide Dialuminum (Al ₂ O ₃ ). Furthermore, if the target material is selected in consideration of the adhesion of ions, it is better to include titanium (Ti), which can improve the adhesion of ions and further facilitate the adhesion of ions. In addition, the cost of non-conductive targets is lower than that of conductive targets, which has the characteristics of reducing costs. In this embodiment, titanium diboride (TiB ₂ ) is selected as the target material, and the surface of the blade portion 14 of the microdrill 10 is sputtered and deposited to form a second coating layer 40 (as shown in FIG. 6 ). The second coating layer 40 has a thickness of 3 μm. Experiments have proved that it is more appropriate when the coating thickness of the second coating layer 40 is 3 μm. It is foreseeable that the second coating layer 40 will form a relatively flat surface where the metal droplets form protrusions, which can reduce the impact caused by the metal droplets, so that the second coating layer 40 can simultaneously improve the mechanical properties and drill holes. The precision of the operation is required to achieve better results. The second coating layer 40 is an alloy with carbon-base, boron-base, nitrogen-base or titanic-base.

Thus, the present invention, through the above-mentioned steps, first treats the surface of the micro-drilling needle with arc deposition (arc deposition) to provide better hardness, and then coats the surface with sputter deposition (sputter deposition) , can form a smooth surface on the edge of the micro-drill to reduce the formation of friction. Compared with conventional methods, it can provide micro-drills with high hardness, low friction coefficient, and high stability mechanical properties, and has the characteristics of wear resistance and improved processing accuracy.

Furthermore, prior to depositing coatings by sputtering on the surface of the conventional microdrill, it is necessary to prepare an under-layer with high adhesion on the surface of the blade of the microdrill in advance, so as to facilitate the adhesion of the second coating layer. The present invention can make the second coating layer adhere without prefabricating the under-layer, especially when the non-conductive target material is used for sputtering deposition, its adhesion is compared with that of the conventional prefabricated under-layer Way higher, featuring a simplified sputter deposition step. In addition, when a non-conductive target with high hardness is selected for sputtering deposition coating, the second coating layer can also have the characteristics of high hardness and wear resistance, which can further improve the mechanical properties of the micro-drill blade. Extend the life of microdrills.

It can be seen from the above examples that the present invention firstly provides the mechanical properties of high hardness of the micro-drill blade by arc deposition, so that it has the characteristics of wear resistance, and then provides the micro-drill blade by sputtering deposition. Forms a smooth surface, can reduce the formation of uneven surfaces, and has the characteristics of a low coefficient of friction. Therefore, compared with the conventional coating method, the present invention can overcome the shortcomings of arc deposition coating surface roughness and sputtering deposition coating adhesion, and further improve the mechanical properties of the micro-drill blade, so that the micro-drill has a higher stability and long service life. Of course, in terms of implementation, the micro-drill surface electroplating method of the present invention can not only process the cutting edge of the drill, but also be suitable for processing the entire drill.

To sum up, the constituent components and method steps disclosed in the above embodiments of the present invention are only for illustration and cannot be used to limit the protection scope of the present invention. The protection scope of the present invention should be determined by the claims. Substitution or change of other equivalent components or steps shall be included in the patent protection scope of the present invention.

Claims (14)

1. A microdrilling needle surface electroplating method is characterized in that comprising the following steps: a) providing a micro-drilling needle and a vacuum chamber, placing the micro-drilling needle in the vacuum chamber; b) Depositing the surface of the micro-drill by arc deposition to form a first coating layer; c) Depositing the surface of the first coating layer by sputtering to form a second coating layer. 2. The surface electroplating method for micro-drilling needles as claimed in claim 1, characterized in that: the micro-drilling needles in step a) remove surface oil stains and dry moisture with ultrasonic waves in advance, and then place them in the vacuum chamber Inside. 3. The surface electroplating method for micro-drilling needles according to claim 1, characterized in that: the vacuum chamber in step a) has a vacuum pipeline for evacuating the vacuum chamber into a vacuum state. 4. The surface electroplating method for micro-drilling needles according to claim 3, characterized in that: the vacuum chamber in step a) is evacuated to 8×10 ⁻³ Pa. 5. The microdrill surface electroplating method as claimed in claim 1, characterized in that: the arc deposition method described in step b) is rotary arc deposition. 6. The microdrill surface electroplating method as claimed in claim 1, characterized in that: the first coating layer in step b) has a thickness below 3 μm. 7. The surface electroplating method of the microdrill according to claim 1, characterized in that: the sputtering deposition method described in step c) is unbalanced magnetron sputtering deposition. 8. The microdrill surface electroplating method according to claim 7, characterized in that: the second coating layer in step c) is deposited by sputtering with a non-conductive target. 9. The surface electroplating method for micro-drilling needles as claimed in claim 8, characterized in that: the non-conductive target material described in step c) is selected from one of titanium diboride, aluminum oxide and boron nitride . 10. The surface electroplating method for micro-drilling needles according to claim 1, characterized in that: the second coating layer in step c) has a thickness below 3 μm. 11. A thin film made by the electroplating method according to claim 1, characterized in that it comprises: a micro drill; A first coating layer is formed on the surface of the micro-drill by arc deposition; A second coating layer is formed on the surface of the first coating layer by sputtering deposition. 12. The surface electroplating method of the micro-drill according to claim 11, characterized in that: the thickness of the first coating layer is below 3 μm. 13. The surface electroplating method for micro-drilling needles according to claim 11, characterized in that: the thickness of the second coating layer is below 3 μm. 14. The surface electroplating method for micro-drilling needles according to claim 11, characterized in that: the second coating layer is an alloy with a carbon base, a boron base, a nitrogen base or a titanium base.

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