CN117604451A - Carbon-based coating for surface of cutter, preparation method of carbon-based coating and cutter - Google Patents

Abstract

The invention provides a carbon-based coating for a cutter surface, a preparation method thereof and a cutter, wherein the carbon-based coating sequentially comprises high sp content from the cutter surface to the outside ³ Bond carbon layer, graded layer and high sp content ² A bonded carbon layer having a high sp content ³ Sp in the carbon bond layer ³ The bond content is 50-80%, the high sp content ² Sp in the carbon bond layer ² The bond content is 50-80%, sp is from inside to outside in the gradual change layer ³ The bond content is from high to low. The invention is respectively provided with sp ³ Bond and sp ² A carbon layer with a main bond, the former provides higher hardness and wear resistance, and the latter has low friction coefficient and better lubricity; the invention is arranged on two carbon layersThe gradual change layer is arranged between the two layers, so that gradual change transition of the properties of the two layers is realized, the problem of poor combination is avoided, the stability is improved, meanwhile, the internal stress in the coating is reduced, the risk of easy breakage is avoided, and the deposition with large thickness is realized; the carbon-based coating has the advantages of simple structure, stable performance, lower cost and wider application range.

Description

A kind of carbon-based coating for tool surface, its preparation method and tool

Technical field

The invention belongs to the technical field of tool coatings and relates to a carbon-based coating used on the surface of tools, its preparation method and tools.

Background technique

Printed circuit boards are the carrier of the modern information industry. As information transmission develops in the direction of high frequency, high speed, and low loss, the thickness of printed circuit boards and the proportion of hard fillers gradually increase, and the number of micropores gradually increases. The increase in the viscosity of the plastic resin will lead to increased wear of the micro-drills used in mechanical drilling and difficulty in chip removal. In severe cases, the tool may break, affecting the processing efficiency and quality of printed circuit boards. Therefore, the wear resistance of micro-tools needs to be improved to increase their service life. At the same time, the surface of the drill bit needs to have high lubricity to improve the chip removal performance of the tool and avoid tool breakage caused by dust plugging.

Coating technology is one of the most effective means to improve the surface properties of materials. The performance requirements for coatings usually include hardness, wear resistance and friction coefficient. Existing wear-resistant coatings are usually metal coatings or ceramic coatings. , such as TiAlN, CrAlN or TiSiN, etc. Although the above coatings have high hardness and excellent wear resistance, their friction coefficient is also high, which easily causes wear and cannot meet the requirements for good chip removal. As a new type of coating, diamond-like coating includes tetrahedral carbon coating, which has the characteristics of high hardness and low friction coefficient. It is widely used in tool coating processing, but its internal stress is high and the coating is thickened. It is easy to cause the risk of breakage, and it is impossible to prepare a large-thickness coating. However, the coating thickness is low, and the wear resistance of the tool is limited, affecting its service life.

CN 101432462A discloses a substrate coated with a multilayer structure including a tetrahedral carbon layer and a softer outer layer. The multilayer structure includes an adhesion promotion layer, an intermediate layer and an amorphous carbon layer. The intermediate layer includes Young's A tetrahedral carbon layer with a modulus above 200 GPa, with a sp ³ bonded carbon fraction above 50%, including non-hydrogenated tetrahedral carbon or hydrogenated tetrahedral carbon, and an amorphous carbon layer with a Young's modulus below 200 GPa, with The sp ³ bonded carbon fraction is less than 40%, including amorphous hydrogenated carbon or diamond-like nanocomposite layers; the tetrahedral carbon layer and the amorphous carbon layer in this multi-layer structure are in direct contact, and the performance changes of the two are more abrupt and easy to As a result, the bonding strength is weakened, and the structural layer is prone to breakage or separation during application, affecting the service life.

CN 103317793A discloses a diamond-like nanocomposite coating tool and a preparation method thereof. A connecting layer, a gradient layer and a main wear-resistant layer are sequentially attached to the tool substrate from the inside to the outside; the connecting layer is molybdenum, and the gradient layer is molybdenum. The layer is attached to the connecting layer, the gradient layer is a Mo-C layer, and the carbon content in the gradient layer gradually increases from the inside to the outside; the main wear-resistant layer is attached to the gradient layer, and the main wear-resistant layer is doped with molybdenum carbide. Diamond-like coating, namely MoC-DLC layer. The diamond-like coating in this composite coating is located on the outermost side. This structural layer mainly plays a wear-resistant role, but it is still a structural layer with a high sp ³ bond content. The internal stress is large, and the thickening of the coating can easily cause breakage. , unable to achieve long-term wear resistance and low service life.

To sum up, for the selection of carbon-based coating on the tool surface, it is necessary to set up different carbon-based structural layers according to the characteristics of sp ³ bonds and sp ² bonds, so as to ensure the hardness and wear resistance while maintaining a low friction coefficient. Improves lubricity and enables large thickness deposition of coatings.

Contents of the invention

In view of the problems existing in the prior art, the purpose of the present invention is to provide a carbon-based coating for the surface of the tool, its preparation method and the tool. The carbon-based coating is based on the difference in sp ³ bond and sp ² bond content. Carbon layers mainly composed of sp ³ bonds or sp ² bonds are respectively set. The former provides higher hardness and wear resistance, while the latter has a low friction coefficient and good lubricity; and a gradient layer is set between the two. This enables the properties of the two to achieve a gradual transition, avoiding the problems of poor bonding, easy delamination or damage due to large differences in properties, and improving the stability of the carbon-based coating.

To achieve this goal, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a carbon-based coating for a tool surface. The carbon-based coating sequentially includes a high-content sp ³ -bonded carbon layer, a gradient layer and a high-content sp ² -bonded carbon outward from the tool surface. layer, the sp ³ bond content in the high-content sp ³ -bond carbon layer is 50 to 80%, such as 50%, 55%, 60%, 65%, 70%, 75% or 80%, etc., the high-content sp The sp ² bond content in the ^2- bond carbon layer is 50 to 80%, such as 50%, 55%, 60%, 65%, 70%, 75% or 80%, etc., but is not limited to the listed values. Other unlisted values within the range are also applicable; from the inside to the outside of the gradient layer, the sp ³ bond content is from high to low, and the sp ² bond content is from low to high.

In the present invention, for the structure selection of the carbon-based coating on the surface of the tool, according to its performance requirements, carbon layers with high content of sp ³ bonds and high content of sp ² bonds are respectively set. The sp ³ bonds of carbon are diamond structures, and the sp ² bonds of carbon are The bond is a graphite structure, and the difference in the ratio of the two will affect the performance of the coating. The former is located on the side of the tool matrix, with higher sp ³ bond content, greater hardness, and excellent wear resistance. The latter is located on the air side, with sp ² bond The content is higher, the friction coefficient is low, and the lubrication performance is more excellent; in the present invention, a gradient layer is set between the two, that is, the content of sp ³ bonds and sp ² bonds gradually changes to achieve the transition of properties in the two carbon layers and avoid due to The problem of poor bonding caused by large differences in performance can improve the stability of the carbon-based coating, and at the same time reduce the internal stress in the coating, avoid the risk of easy breakage due to thickening of the coating, and achieve large-thickness deposition; so The carbon-based coating has a simple structure, stable performance, low cost and wide application range.

In the present invention, the test of the sp ³ bond content in the carbon layer includes: from the coating surface to the direction of the tool, the sp ³ bond content of the carbon layer at different depths is etched with argon ions to a certain thickness of the carbon-based coating to obtain the corresponding Deep carbon-based coating surface, and then use X-ray photoelectron spectroscopy to measure the proportion of carbon with sp ³ bonds to the total amount of sp ³ bonds and sp ² bonds in the coating.

The following are preferred technical solutions of the present invention, but are not limited to the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

As a preferred technical solution of the present invention, the thickness of the high-content sp ^3- bond carbon layer is 0.1 to 5 μm, such as 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm. Or 5 μm, etc., but it is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

Preferably, the hardness of the high-content sp ³ bond carbon layer is 45 to 65 GPa, such as 45 GPa, 50 GPa, 55 GPa, 60 GPa or 65 GPa, etc., but is not limited to the listed values, and other unlisted values within this range are the same. Be applicable.

Preferably, the thickness of the high-content sp ² bond carbon layer is 0.1 to 5 μm, such as 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm or 5 μm, etc., but It is not limited to the listed values, and other unlisted values within the range of values are also applicable.

Preferably, the hardness of the high-content sp ² bond carbon layer is 20 to 45 GPa, such as 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa or 45 GPa, etc., but is not limited to the listed values. Other values within this range are not listed. The same applies to numerical values.

In the present invention, the hardness of the carbon layer is detected by a nanoindentation instrument.

Preferably, the thickness of the gradient layer is 0.1 to 3 μm, such as 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm, etc., but is not limited to the listed values. Other values within this range are not listed. The same applies to numerical values.

Preferably, the sp ³ bond content in the gradient layer decreases from the sp ³ bond content ⁱⁿ the carbon layer with high sp ^{3 bond content to the sp 3} bond content in the carbon layer with high sp ² bond content.

Preferably, the sp ³ bond content or sp ² bond content in the gradient layer changes continuously or gradiently.

Preferably, during the continuous gradient, the sp ³ bond content or sp ² bond content changes linearly and uniformly or nonlinearly.

Preferably, when the gradient is gradually changing, the gradient layer is composed of at least two gradient layers with different sp ³ bond contents.

Preferably, the thickness of a single gradient layer is 0.02-1 μm, such as 0.02 μm, 0.05 μm, 0.1 μm, 0.3 μm, 0.5 μm, 0.6 μm, 0.8 μm or 1 μm, etc., but is not limited to the listed values. This range of values Other values not listed within are also applicable.

In the present invention, as the sp ³ bond content or sp ² bond content in the gradient layer changes, the corresponding hardness also changes, and the changing trend is: the sp ³ bond content continues or gradient decreases, while the sp ² bond content continues or decreases. As the gradient increases, the hardness of the coating gradually decreases, that is, in the gradient layer, the gradient transition is achieved by controlling the proportion of sp ³ bonds and sp ² bonds in the coating, which is divided into continuous gradient and gradient gradient; during continuous gradient, the content of sp ³ bonds along the As the thickness direction decreases, the rate curve can be linear and constant or nonlinear, as shown in Figure 1. When the gradient gradient changes, the gradient layer consists of multiple structural layers with different sp ³ bond content. Sp between adjacent gradient layers The difference in the ³ -bond content and the thickness of the single layer can be equal or different, as shown in Figure 2.

In the present invention, the hardness of the carbon-based coating is 20 to 65 GPa, such as 20 GPa, 25 GPa, 30 GPa, 35 GPa, 40 GPa, 45 GPa, 50 GPa, 55 GPa, 60 GPa or 65 GPa, etc., and the overall thickness is 0.5 to 8 μm, such as 0.5 μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm or 8μm, etc.

As a preferred technical solution of the present invention, the high-content sp ² bond carbon layer includes a pure carbon coating or an element-doped carbon coating.

Preferably, the doped elements include any one or a combination of at least two of silicon, nitrogen, hydrogen, chromium, titanium, tantalum, molybdenum, niobium or aluminum. Typical but non-limiting examples of the combination are: silicon And the combination of nitrogen, the combination of chromium and titanium, the combination of nitrogen and aluminum, the combination of silicon, titanium and tantalum, the combination of tantalum, molybdenum and niobium, etc.

Preferably, the carbon-based coating further includes an adhesive layer located between the carbon-based coating and the tool surface.

Preferably, the material of the adhesive layer includes any one or a combination of at least two of a single substance, a corresponding simple substance nitride, a corresponding simple substance carbide, or a corresponding simple substance carbonitride. The combination is typical but not limiting. Examples include: combinations of elemental elements and corresponding elemental nitrides, combinations of corresponding elemental nitrides and corresponding elemental carbides, combinations of corresponding elemental carbides and corresponding elemental carbonitrides, combinations of elemental elements, corresponding elemental nitrides, and The combination of corresponding elemental carbides, etc.

Preferably, the element includes any one or a combination of at least two of chromium, titanium, molybdenum, tungsten, tantalum, vanadium or silicon. Typical but non-limiting examples of the combination include: a combination of chromium and titanium, tungsten and Combinations of tantalum, combinations of titanium and silicon, combinations of molybdenum, tungsten and tantalum, etc.

Preferably, the number of the adhesive layer is at least one, such as one, two or three layers, etc., and the thickness of each adhesive layer is 0.1 to 1 μm, such as 0.1 μm, 0.3 μm, 0.5 μm, 0.6 μm, 0.8 μm or 1 μm, etc., but are not limited to the listed values, and other unlisted values within this numerical range are also applicable.

In the present invention, the bonding force between the carbon-based coating and the tool surface is improved by providing an adhesive layer. The adhesive layer can be one or more layers, and the multiple layers can be a combination of different materials.

In a second aspect, the present invention provides a method for preparing the above-mentioned carbon-based coating. The preparation method includes the following steps:

(1) Fix the tool drill bit and then evacuate, and pass in protective gas to control the pressure, turn on the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode, control the cathode current, and deposit a high-content sp ³ bond carbon layer on the surface of the tool drill bit;

(2) On the basis of step (1), the current of the magnetron sputtering cathode is continuously increased, the current of the magnetically regulated multi-arc cathode is continuously reduced, and a gradient layer is deposited;

(3) On the basis of step (2), continue to control the current of the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode to deposit a high-content sp ² bond carbon layer, thereby obtaining a carbon-based coating.

In the present invention, the content of sp ³ bonds and sp ² bonds in the carbon-based coating is controlled by adjusting the ratio of carbon atoms and carbon ions reaching the tool surface. The greater the proportion of carbon atoms, the higher the content of sp ² bonds in the coating. The greater the proportion of carbon ions, the higher the sp ³ bond content in the coating; among them, carbon atoms are obtained from the magnetron sputtering cathode through the glow discharge method. The greater the magnetron sputtering cathode current or power, the greater the amount of carbon atoms produced. More; carbon ions are obtained by arc discharge method through magnetically adjusted multi-arc cathode. The greater the current or power of magnetically adjusted multi-arc cathode, the more carbon ions are produced; that is, the ratio of carbon atoms and carbon ions requires the coordinated control of two types of cathodes. , a certain angle is formed between the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode. The angle range can be selected from 20 to 180 degrees, such as 20 degrees, 40 degrees, 60 degrees, 90 degrees, 120 degrees, 135 degrees, 150 degrees Or 180 degrees, etc., the angle between the two central axes intersects near the surface of the tool, ensuring that carbon atoms and carbon ions reach the surface at the same time instead of being deposited sequentially; in addition, the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode are paired According to the equipment structure and coating requirements, multiple pairs can be arranged and arranged around the equipment.

As a preferred technical solution of the present invention, the tool drill bit in step (1) is cleaned before being fixed, and the cleaning includes ultrasonic cleaning.

Preferably, the medium used for cleaning includes any one or a combination of at least two of acetone, alcohol or water. Typical but non-limiting examples of the combination include: a combination of acetone and alcohol, a combination of alcohol and water, acetone, The combination of alcohol and water is preferably used sequentially, and the medium is used alone.

Preferably, the cleaning time is independently 10 to 60 min, such as 10 min, 20 min, 30 min, 40 min, 50 min or 60 min, etc., but is not limited to the listed values, and other unlisted values within this range are also applicable.

Preferably, the tool drill bit is dried after cleaning.

Preferably, the tool drill bit in step (1) is placed in a vacuum chamber and fixed on the fixture.

Preferably, the pressure after vacuuming in step (1) is reduced to below 1.0×10 ^-2 Pa, such as 1.0×10 ^-2 Pa, 8.0×10 ^-3 Pa, 6.0×10 ^-3 Pa, 5.0×10 ^-3 Pa, 4.0×10 ^-3 Pa, 2.0×10 ^-3 Pa or 1.0×10 ^-3 Pa, etc., but are not limited to the listed values, and other unlisted values within this numerical range are also applicable.

Preferably, the protective gas in step (1) includes an inert gas.

Preferably, the pressure after the protective gas is introduced in step (1) is 0.1-5Pa, such as 0.1Pa, 0.5Pa, 1Pa, 1.5Pa, 2Pa, 2.5Pa, 3Pa, 4Pa or 5Pa, etc., but is not limited to those listed value, other unlisted values within this value range are also applicable.

Preferably, the current of the magnetron sputtering cathode in step (1) is 0.1 to 2A, such as 0.1A, 0.3A, 0.5A, 0.8A, 1A, 1.2A, 1.5A, 1.8A or 2A, etc., but not Not limited to the listed values, other unlisted values within this range are also applicable.

Preferably, the power of the magnetron sputtering cathode in step (1) is 0.05 to 3kW, such as 0.05kW, 0.1kW, 0.5kW, 1kW, 1.5kW, 2kW, 2.5kW or 3kW, etc., but is not limited to those listed value, other unlisted values within this value range are also applicable.

Preferably, the current of the magnetically adjusted multi-arc cathode in step (1) is 70-300A, such as 70A, 100A, 120A, 150A, 180A, 200A, 220A, 250A, 270A or 300A, etc., but is not limited to those listed Value, other unlisted values within this value range are also applicable.

Preferably, the power of the magnetically adjusted multi-arc cathode in step (1) is 0.5 to 20kW, such as 0.5kW, 1kW, 3kW, 5kW, 8kW, 10kW, 12kW, 15kW, 18kW or 20kW, etc., but is not limited to those listed value, other unlisted values within this value range are also applicable.

Preferably, the deposition time of the high-content sp ³ bond carbon layer in step (1) is 5 to 60 min, such as 5 min, 10 min, 20 min, 30 min, 40 min, 50 min or 60 min, etc., but is not limited to the listed values. The same applies to other values within the numerical range that are not listed.

As a preferred technical solution of the present invention, before the high-content sp ³ bond carbon layer is deposited in step (1), an adhesive layer is first deposited on the surface of the tool drill bit.

Preferably, according to the different materials of the bonding layer, a magnetically adjusted multi-arc cathode is selected to control different atmosphere conditions and currents.

Preferably, when the material of the adhesive layer is a single substance, the controlled pressure of the protective gas is 0.1 to 5 Pa, such as 0.1 Pa, 0.5 Pa, 1 Pa, 1.5 Pa, 2 Pa, 2.5 Pa, 3 Pa, 4 Pa or 5 Pa, etc. The current of the magnetically adjusted multi-arc cathode is 20~300A, such as 20A, 50A, 70A, 100A, 120A, 150A, 180A, 200A, 220A, 250A, 270A or 300A, etc., but it is not limited to the listed values. The same applies to other values within the range not listed.

Preferably, when the material of the adhesive layer is a corresponding elemental nitride, the controlled pressure of the nitrogen gas is 0.5 to 5 Pa, such as 0.5 Pa, 1 Pa, 1.5 Pa, 2 Pa, 2.5 Pa, 3 Pa, 4 Pa or 5 Pa, etc., and the magnetic Adjust the current of the multi-arc cathode to 20~300A, such as 20A, 50A, 70A, 100A, 120A, 150A, 180A, 200A, 220A, 250A, 270A or 300A, etc., but are not limited to the listed values, within the respective value ranges Other values not listed within are also applicable.

Preferably, when the material of the adhesive layer is a corresponding carbide, the control pressure of the carbon-containing gas is 0.2 to 5 Pa, such as 0.2 Pa, 0.5 Pa, 1 Pa, 1.5 Pa, 2 Pa, 2.5 Pa, 3 Pa, 4 Pa. or 5Pa, etc., the current of the magnetically adjusted multi-arc cathode is 20~300A, such as 20A, 50A, 70A, 100A, 120A, 150A, 180A, 200A, 220A, 250A, 270A or 300A, etc., but is not limited to the listed values. , other unlisted values within their respective value ranges are also applicable.

Preferably, when the material of the adhesive layer is a corresponding elemental carbonitride, the controlled pressure of the mixed gas containing carbon and nitrogen is 0.5 to 5 Pa, such as 0.5 Pa, 1 Pa, 1.5 Pa, 2 Pa, 2.5 Pa, 3Pa, 4Pa or 5Pa, etc. The current of the magnetically adjusted multi-arc cathode is 20~300A, such as 20A, 50A, 70A, 100A, 120A, 150A, 180A, 200A, 220A, 250A, 270A or 300A, etc., but it is not limited to all For the numerical values listed, other non-listed values within the respective numerical ranges also apply.

Preferably, the carbonaceous gas includes acetylene and/or methane.

Preferably, when the adhesive layer includes two or more layers, the above single layer deposition processes are combined and superimposed.

In the present invention, according to the type of the adhesive layer, in addition to the corresponding single target material, nitride, carbide or carbonitride also requires corresponding atmospheric conditions, such as nitrogen-containing gas or carbon-containing gas. The former can be nitrogen. , the latter chooses simple organic gases, such as methane, acetylene, etc.

As a preferred technical solution of the present invention, the current of the magnetron sputtering cathode in step (2) is continuously increased from 0.1 to 2A, such as 0.1A, 0.3A, 0.5A, 0.8A, 1.0A, 1.2A, 1.5 A, 1.8A or 2.0A, etc., rising to 20~30A, such as 20A, 22A, 24A, 25A, 27A, 28A or 30A, etc., but are not limited to the listed values, other values not listed are within the respective value ranges The same applies to numerical values.

Preferably, the current of the magnetically regulated multi-arc cathode in step (2) is continuously reduced from 70 to 300A, such as 70A, 90A, 100A, 120A, 150A, 180A, 200A, 250A or 300A, etc., to 20 to 80A, For example, 20A, 30A, 40A, 50A, 60A, 70A, 80A, etc., but are not limited to the listed values, and other unlisted values within the respective numerical ranges are also applicable.

Preferably, the current of the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode in step (2) changes continuously or gradiently.

Preferably, the deposition time of the gradient layer in step (2) is 2 to 120 min, such as 2 min, 5 min, 10 min, 20 min, 30 min, 45 min, 60 min, 80 min, 100 min or 120 min, etc., but is not limited to the listed values. , other unlisted values within this value range are also applicable.

In the present invention, the deposition of the gradient layer requires real-time changes in corresponding cathode current, power and other conditions due to changes in sp ³ bond and sp ² bond content. The two also have a corresponding relationship, but according to the sp ³ bond and sp ² The gradient mode of bond content determines whether different cathode currents and powers change continuously or gradiently.

Preferably, the current of the magnetron sputtering cathode in step (3) is 20 to 30A, such as 20A, 22A, 24A, 25A, 26A, 28A or 30A, etc., but is not limited to the listed values. Within this range of values Other values not listed are also applicable.

Preferably, the power of the magnetron sputtering cathode in step (3) is 10 to 30kW, such as 10kW, 12kW, 15kW, 18kW, 20kW, 22kW, 25kW, 27kW or 30kW, etc., but is not limited to the listed values. Other values within this range that are not listed are also applicable.

Preferably, the current of the magnetically adjusted multi-arc cathode in step (3) is 20 to 30A, such as 20A, 22A, 24A, 25A, 26A, 28A or 30A, etc., but is not limited to the listed values. Within this range of values Other values not listed are also applicable.

Preferably, the power of the magnetically regulated multi-arc cathode in step (3) is 0.05 to 1kW, such as 0.05kW, 0.1kW, 0.2kW, 0.3kW, 0.4kW, 0.5kW, 0.6kW, 0.8kW or 1.0kW, etc., However, it is not limited to the listed values, and other unlisted values within the range of values are also applicable.

Preferably, the deposition time of the high-content sp ² bond carbon layer in step (3) is 2 to 600 min, such as 2 min, 10 min, 30 min, 50 min, 75 min, 100 min, 150 min, 200 min, 300 min, 400 min, 500 min or 600 min, etc., However, it is not limited to the listed values, and other unlisted values within the range of values are also applicable.

In a third aspect, the present invention provides a tool, which includes a drill bit and the above-mentioned carbon-based coating. The drill bit includes a spiral groove, a peripheral edge and a drill tip, and the spiral groove spirally extends from the drill tip to the end of the drill bit, The carbon-based coating can be divided into three situations: completely covering the drill bit area, partially covering the drill bit area, or partially covering and then adding an overall protective layer.

As a preferred technical solution of the present invention, the body diameter of the drill bit is 0.075~6mm, such as 0.075mm, 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm or 6mm, etc., but is not limited to the listed values. , other unlisted values within this value range are also applicable.

Preferably, the axial length of the spiral groove accounts for more than 80% of the length of the drill bit, such as 80%, 85%, 90%, 95% or 100%, etc., but is not limited to the listed values, and other values within this value range The same applies to non-enumerated values.

Preferably, the number of said spiral grooves is at least one, such as one, two or three.

Preferably, the depth of the spiral groove accounts for 5% to 52% of the diameter of the drill bit, such as 5%, 10%, 15%, 20%, 25%, 30%, 40%, 50% or 52%, etc., but not only Limited to the listed values, other unlisted values within this range are also applicable.

As a preferred technical solution of the present invention, the carbon-based coating completely covering the drill bit area means completely covering the spiral groove, peripheral cutting edge and drill tip.

In the present invention, this method requires full coverage of the drill bit area. When the tool size is small, the fully covered coating, especially when the coating thickness is large, has a greater impact on the diameter of the drill bit, that is, on the chip removal ability. It is huge and can easily cause tool breakage. Therefore, this coating method is mainly suitable for printed circuit board processing that requires high wear resistance and slightly low requirements for chip removal.

Preferably, the carbon-based coating partially covers the drill bit area to cover the peripheral cutting edge in the drill bit area.

Preferably, the length of the circumferential edge covered with the carbon-based coating accounts for 5 to 100% of the length of the spiral groove, such as 5%, 10%, 20%, 30%, 40%, 50%, 60%, 80% or 100%, etc., but are not limited to the listed values, and other unlisted values within this numerical range are also applicable.

In the present invention, the carbon-based coating only covers the peripheral edge of the drill bit. The length of the coating on the peripheral edge extends from the drill tip to the end of the spiral groove according to the processing materials and the drill bit structure, and is limited to a certain length ratio. , and there is no carbon-based coating on the surface of the spiral groove and drill tip. This coating covering method is mainly used for processing difficult-to-process printed circuit boards with large coating thickness and certain requirements for chip removal. It improves wear resistance while , does not affect the chip removal ability of the drill bit during deep hole processing.

Preferably, the partial covering followed by the overall protective layer is to cover the peripheral edge in the drill bit area and then deposit a low friction coating as a whole.

Preferably, the thickness of the low friction coating is 0.05-0.5 μm, such as 0.05 μm, 0.1 μm, 0.15 μm, 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm or 0.5 μm, etc., and the friction The coefficient is less than 0.1, such as 0.1, 0.08, 0.06, 0.05, 0.04, 0.02 or 0.01, etc., but is not limited to the listed values, and other unlisted values within the respective numerical ranges are also applicable.

In the present invention, based on the second coating coverage, another layer of carbon-based coating with wear resistance and ultra-low friction coefficient is deposited on the entire drill bit area. Its friction coefficient is much lower than the 0.6 of conventional cemented carbide. ~0.8, this structural design is mainly aimed at the application of high-end difficult-to-process printed circuit boards with extremely high requirements on drill bit wear resistance and chip removal performance; the low-friction coating has a small thickness and has almost no impact on the core thickness, and can effectively Improve chip removal capability.

In the present invention, the tool is not limited to double-edged micro drill bits, but is also suitable for various standard and non-standard structure micro drill bits on the market. Milling cutters, reamers, broaches, molds, gears, etc. can also be selected for wear-resistant and Where lubricity is required.

Compared with the prior art, the present invention has the following beneficial effects:

(1) According to the different contents of sp ³ bonds and sp ² bonds, the present invention sets carbon layers mainly composed of sp ³ bonds and sp ² bonds respectively. The former provides higher hardness and wear resistance, while the latter has a low friction coefficient. Has good lubricity;

(2) The present invention sets a gradient layer between the carbon layers dominated by sp ³ bonds and sp ² bonds, so that the properties of the two can achieve a gradual transition, avoid poor bonding due to large differences in properties, and improve the carbon-based The stability of the coating can also reduce the internal stress in the coating, avoid the risk of easy breakage due to thickening of the coating, and achieve large thickness deposition;

(3) The carbon-based coating and tool structure of the present invention can effectively solve the processing problems of difficult-to-process high-frequency printed circuit boards, high-speed printed circuit boards, and high-performance packaging substrates, and are conducive to the new generation of communication technology, chip industry, and high-performance packaging substrates. The development of performance computing industry has a wide range of applications.

Description of drawings

Figure 1 is a variation curve of the sp ³ bond content along the thickness direction when the gradient layer continuously gradients provided in the specification of the present invention;

Figure 2 is a variation curve of sp ³ bond content along the thickness direction when the gradient layer of the gradient layer provided in the specification of the present invention gradually changes;

Figure 3 is a schematic structural diagram of the drill bit provided in Embodiment 1 of the present invention;

Figure 4 is a partial enlarged view of the drill bit provided in Embodiment 1 of the present invention;

Figure 5 is a schematic structural diagram of the drill tip in the drill bit provided in Embodiment 1 of the present invention;

Figure 6 is a schematic structural diagram of the carbon-based coating provided in Embodiment 2 of the present invention;

Figure 7 is a schematic structural diagram of the drill bit provided in Embodiment 2 of the present invention;

Figure 8 is a partial enlarged view of the drill bit provided in Embodiment 2 of the present invention;

Figure 9 is a schematic structural diagram of the drill tip in the drill bit provided in Embodiment 2 of the present invention;

Figure 10 is a schematic structural diagram of a drill bit provided in Embodiment 3 of the present invention;

Figure 11 is a partial enlarged view of the drill bit provided in Embodiment 3 of the present invention;

Figure 12 is a schematic structural diagram of the drill tip in the drill bit provided in Embodiment 3 of the present invention;

Figure 13 is an XPS test result diagram of the high-content sp ³ bond carbon layer in the carbon-based coating provided in Example 6 of the present invention;

Figure 14 is an XPS test result diagram of the high-content sp ² bond carbon layer in the carbon-based coating provided in Example 6 of the present invention;

Figure 15 is a diagram showing the results of the tool breakage rate when processing the E705G package substrate with different tools provided in Embodiment 6 of the present invention;

Figure 16 is a graph showing the wear results of different tools after processing the E705G packaging substrate provided in Embodiment 6 of the present invention;

Among them, 1-high-content sp ³ -bond carbon layer, 2-gradient layer, 3-high-content sp ^2- bond carbon layer, 4-adhesive layer, 5-spiral groove, 6-circular edge, 7-drill tip.

Detailed ways

In order to better explain the present invention and facilitate understanding of the technical solution of the present invention, the present invention will be described in further detail below. However, the following embodiments are only simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be determined by the claims.

The following are typical but non-limiting embodiments of the present invention:

Example 1:

This embodiment provides a carbon-based coating for the tool surface and the tool. The carbon-based coating sequentially includes a high-content sp ³ bond carbon layer 1, a gradient layer 2 and a high-content sp ² bond outward from the tool surface. Carbon layer ³ , the sp ^{3 bond content in the high-content sp 3} bond carbon layer 1 is 52.9%, the sp ² bond content in the high-content sp ² bond carbon layer 3 is 62.6%, and the gradient layer 2 is from inside to To the outside, the sp ³ bond content goes from high to low, and the sp ² bond content goes from low to high.

The thickness of the high-content sp ^3- bond carbon layer 1 is 0.15 μm, and the hardness is 52.1 GPa.

The thickness of the high-content sp ² bond carbon layer 3 is 0.2 μm, and the hardness is 35.6 GPa.

The thickness of the gradient layer 2 is 0.2 μm, and the sp ³ bond content in the gradient layer 2 changes linearly and continuously from 52.9% to 37.4%.

The tool includes a drill bit and a carbon-based coating on the surface of the drill bit. The structural diagram of the drill bit is shown in Figure 3, and its partial enlarged view is shown in Figure 4. It includes a spiral groove 5, a peripheral edge 6 and a drill tip 7. The structural schematic diagram of the drill tip is shown in Figure 5. The spiral groove 5 spirally extends from the drill tip 7 to the end of the drill bit. The carbon-based coating partially covers the drill bit area, that is, covers the peripheral cutting edge 6 in the drill bit area.

The drill bit has a body diameter of 0.15mm.

The axial length of the spiral groove 5 accounts for 100% of the drill bit length, the number of the spiral grooves 5 is two, and the depth of the spiral groove 5 accounts for 28% of the drill bit diameter.

The length of the circumferential edge 6 covered with the carbon-based coating accounts for 50% of the length of the spiral groove 5 .

Example 2:

This embodiment provides a carbon-based coating for the tool surface and the tool. The structural diagram of the carbon-based coating is shown in Figure 6. It includes a high-content sp ³ bond carbon layer 1 and 1 in the order outward from the tool surface. Gradient layer 2 and high content sp ² bond carbon layer 3, the sp ³ bond content in the high content sp ³ bond carbon layer 1 is 60.3%, and the sp ² bond content in the high content sp ² bond carbon layer 3 is 75.4% , the sp ³ bond content in the gradient layer 2 goes from high to low from the inside to the outside, and the sp ² bond content goes from low to high.

The thickness of the high-content sp ^3- bond carbon layer 1 is 0.2 μm, and the hardness is 56.5 GPa.

The thickness of the high-content sp ² bond carbon layer 3 is 0.3 μm, and the hardness is 22.5 GPa.

The thickness of the gradient layer 2 is 0.5 μm, and the sp ³ bond content in the gradient layer 2 is a nonlinear continuous gradient, from 60.3% to 24.6%.

The carbon-based coating also includes an adhesive layer 4, which is located between the carbon-based coating and the tool surface.

The material of the adhesive layer 4 is chromium, and the thickness of the adhesive layer 4 is 0.2 μm.

The tool includes a drill bit and a carbon-based coating on the surface of the drill bit. The structural diagram of the drill bit is shown in Figure 7, and its partial enlarged view is shown in Figure 8. It includes a spiral groove 5, a peripheral edge 6 and a drill tip 7. The structural schematic diagram of the drill tip is shown in Figure 9. The spiral groove 5 extends spirally from the drill tip 7 to the end of the drill bit. The carbon-based coating completely covers the drill bit area, that is, the spiral groove 5, the peripheral edge 6 and the drill tip 7. All covered.

The drill bit has a body diameter of 0.25mm.

The axial length of the spiral groove 5 accounts for 95% of the drill bit length, the number of the spiral grooves 5 is two, and the depth of the spiral groove 5 accounts for 30% of the drill bit diameter.

Example 3:

This embodiment provides a carbon-based coating for the tool surface and the tool. The carbon-based coating sequentially includes a high-content sp ³ bond carbon layer 1, a gradient layer 2 and a high-content sp ² bond outward from the tool surface. Carbon layer ³ , the sp ^{3 bond content in the high-content sp 3} bond carbon layer 1 is 71.7%, the sp ² bond content in the high-content sp ² bond carbon layer 3 is 60.6%, and the gradient layer 2 is from inside to To the outside, the sp ³ bond content goes from high to low, and the sp ² bond content goes from low to high.

The thickness of the high-content sp ^3- bond carbon layer 1 is 0.5 μm, and the hardness is 60.8 GPa.

The thickness of the high-content sp ² bond carbon layer 3 is 1.5 μm, and the hardness is 33.9 GPa.

The thickness of the gradient layer 2 is 1.0 μm, and the sp ³ bond content in the gradient layer 2 is gradient, from 71.7% to 30.4%.

The gradient layer 2 is composed of two gradient layers with different sp ³ bond contents, and the thickness of a single gradient layer is 0.5 μm.

The tool includes a drill bit and a carbon-based coating on the surface of the drill bit. The structural diagram of the drill bit is shown in Figure 10, and its partial enlarged view is shown in Figure 11. It includes a spiral groove 5, a peripheral edge 6 and a drill tip 7. The structural schematic diagram of the drill tip is shown in Figure 12. The spiral groove 5 spirally extends from the drill tip 7 to the end of the drill bit. The carbon-based coating partially covers the drill bit area and an overall protective layer is added, that is, the peripheral edge in the drill bit area. 6After covering, deposit a layer of low friction coating as a whole.

The drill bit has a body diameter of 0.9mm.

The axial length of the spiral groove 5 accounts for 90% of the drill bit length, the number of the spiral grooves 5 is two, and the depth of the spiral groove 5 accounts for 25% of the drill bit diameter.

The length of the circumferential edge 6 covered with the carbon-based coating accounts for 80% of the length of the spiral groove 5 .

The thickness of the low-friction coating is 0.1 μm, covering the entire surface of the drill bit area, and the friction coefficient is 0.08.

Example 4:

This embodiment provides a carbon-based coating for the tool surface and the tool. The carbon-based coating sequentially includes a high-content sp ³ bond carbon layer 1, a gradient layer 2 and a high-content sp ² bond outward from the tool surface. Carbon layer ³ , the sp ^{3 bond content in the high content sp 3} bond carbon layer 1 is 76%, the sp ² bond content in the high content sp ² bond carbon layer 3 is 77%, the gradient layer 2 is from the inside To the outside, the sp ³ bond content goes from high to low, and the sp ² bond content goes from low to high.

The thickness of the high-content sp ^3- bond carbon layer 1 is 0.8 μm, and the hardness is 62.2 GPa.

The thickness of the high-content sp ² bond carbon layer 3 is 0.9 μm, and the hardness is 20.6 GPa.

The thickness of the gradient layer 2 is 0.8 μm, and the sp ³ bond content in the gradient layer 2 is a nonlinear continuous gradient, from 76% to 23%.

The carbon-based coating also includes an adhesive layer 4, which is located between the carbon-based coating and the tool surface.

The adhesive layer 4 includes a chromium adhesive layer and a chromium nitride adhesive layer in sequence. The thickness of the chromium adhesive layer is 0.2 μm, and the thickness of the chromium nitride adhesive layer is 0.3 μm.

The tool includes a drill bit and a carbon-based coating on the surface of the drill bit. The drill bit includes a spiral groove 5, a peripheral edge 6 and a drill tip 7. The spiral groove 5 spirally extends from the drill tip 7 to the end of the drill bit. The carbon-based coating The layer completely covers the drill bit area, that is, the spiral groove 5, the peripheral edge 6 and the drill tip 7 are all covered.

The drill bit has a body diameter of 2.0mm.

The axial length of the spiral groove 5 accounts for 85% of the drill bit length, the number of the spiral grooves 5 is one, and the depth of the spiral groove 5 accounts for 40% of the drill bit diameter.

Example 5:

This embodiment provides a carbon-based coating for the tool surface and the tool. The carbon-based coating sequentially includes a high-content sp ³ bond carbon layer 1, a gradient layer 2 and a high-content sp ² bond outward from the tool surface. Carbon layer ³ , the sp 3 bond content in the high-content sp ³ bond carbon layer 1 is 65%, the sp ² bond content in the high-content sp ² bond carbon layer 3 is 55%, and the gradient layer 2 is from inside to To the outside, the sp ³ bond content goes from high to low, and the sp ² bond content goes from low to high.

The thickness of the high-content sp ^3- bond carbon layer 1 is 5 μm, and the hardness is 58.5 GPa.

The thickness of the high-content sp ² bond carbon layer 3 is 4.5 μm, and the hardness is 40.5 GPa.

The high-content sp ² bond carbon layer 3 is an element-doped carbon coating, and the doping element is silicon.

The thickness of the gradient layer 2 is 2.5 μm, and the sp ³ bond content in the gradient layer 2 is gradient, from 65% to 45%.

The gradient layer 2 is composed of three gradient layers with different sp ³ bond contents, which are 60%, 55% and 50% respectively, and their corresponding thicknesses are 0.8 μm, 0.9 μm and 0.8 μm respectively.

The carbon-based coating also includes an adhesive layer 4, which is located between the carbon-based coating and the tool surface.

The adhesive layer 4 includes a silicon nitride adhesive layer, and the thickness of the adhesive layer 4 is 1 μm.

The tool includes a drill bit and a carbon-based coating on the surface of the drill bit. The drill bit includes a spiral groove 5, a peripheral edge 6 and a drill tip 7. The spiral groove 5 spirally extends from the drill tip 7 to the end of the drill bit. The carbon-based coating The layer partially covers the drill bit area and then an overall protective layer is added, that is, after covering the peripheral edge 6 in the drill bit area, a layer of low friction coating is then deposited as a whole.

The drill bit has a body diameter of 6mm.

The axial length of the spiral groove 5 accounts for 80% of the drill bit length, the number of the spiral grooves 5 is two, and the depth of the spiral groove 5 accounts for 20% of the drill bit diameter.

The length of the circumferential edge 6 covered with the carbon-based coating accounts for 100% of the length of the spiral groove 5 .

The thickness of the low-friction coating is 0.5 μm, covering the entire surface of the drill bit area, and the friction coefficient is 0.1.

Example 6:

This embodiment provides a method for preparing a carbon-based coating for a tool surface. The carbon-based coating is the carbon-based coating in Embodiment 1. The method includes the following steps:

(1) The tool drill bit is first ultrasonic cleaned. The cleaning media are acetone, alcohol and water. Each medium is used separately. The cleaning time is 20 minutes. After cleaning, dry it. Then place the tool drill bit in the vacuum chamber and fix it. On the fixture, evacuate until the pressure drops to 1.0×10 ^-2 Pa, and pass in argon gas to control the pressure to 0.3 Pa. Turn on the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode, and control the current of the magnetron sputtering cathode. The current is 0.4A, the power is 0.2kW, the current of the magnetically adjusted multi-arc cathode is 200A, the power is 5kW, and it is deposited on the surface of the tool drill bit for 20 minutes to obtain a high-content sp ^3- bond carbon layer;

(2) On the basis of step (1), adjust the current of the magnetron sputtering cathode to continuously increase from 0.4A to 20A, and continuously decrease the current of the magnetically adjusted multi-arc cathode from 200A to 30A. Deposit for 20 minutes. Get the gradient layer;

(3) On the basis of step (2), introduce argon gas to control the pressure to 0.85Pa, and continue to control the current of the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode. The current of the magnetron sputtering cathode is 20A, and the power is 12kW, the current of the magnetically adjusted multi-arc cathode is 30A, the power is 0.8kW, and the deposition is 80min to obtain a high-content sp ² bond carbon layer, thereby obtaining a carbon-based coating, which covers the peripheral edge in the drill bit area. Location.

The high-content sp ³ -bond carbon layer and the high-content sp ^2- bond carbon layer in the carbon-based coating obtained in this example were subjected to XPS testing, and the test results are shown in Figures 13 and 14 respectively; The tool is used to process the E705G package substrate, and the number of holes processed is 10,000. The use of the tool is compared with the tool without coating and the tool with TiAlN coating. The result of the tool breakage rate is shown in Figure 15. The tool after processing The outer diameter changes, and the wear situation is shown in Figure 16.

In this embodiment, according to the curve in Figure 13, it is calculated that the sp ³ bond content in the high-content sp ³ -bond carbon layer is 52.9%. According to the curve in Figure 14, it is calculated that the sp in the high-content sp ^2- bond carbon layer is 52.9%. The ^2- bond content is 62.6%; as can be seen from Figure 15, the coated tool in this example did not break after use, while the tool breakage rate of the tool without coating and the tool covered with TiAlN coating was 3‰ respectively. and 2‰; it can be seen from Figure 16 that after processing the 10,000-hole E705G package substrate, the outer diameter of the coated tool in this example is only reduced by 2.1 μm, the outer diameter of the tool without coating is reduced by 14.2 μm, and the outer diameter of the tool covered with TiAlN coating is reduced by 14.2 μm. The outer diameter of the tool is reduced by 7.7 μm. It can be seen that the pure carbon coating in this embodiment has obvious wear resistance advantages;

In summary, the carbon-based coating increases the lubricity and wear resistance of the tool surface, reduces the tool breakage rate, improves the tool wear resistance, and can effectively extend the service life of the tool.

Example 7:

This embodiment provides a method for preparing a carbon-based coating for a tool surface. The carbon-based coating is the carbon-based coating in Embodiment 2. The method includes the following steps:

(1) The tool drill bit is first ultrasonic cleaned. The cleaning media are acetone, alcohol and water. Each medium is used separately. The cleaning time is 30 minutes. After cleaning, dry it. Then place the tool drill bit in the vacuum chamber and fix it. On the fixture, evacuate until the pressure drops to 9.0×10 ^-3 Pa, and pass in argon gas to control the pressure to 2.0 Pa. Turn on the magnetically adjusted multi-arc cathode, control the current of the magnetically adjusted multi-arc cathode to 60A, and install the magnetically adjusted multi-arc cathode on the tool drill bit. Deposit on the surface for 10 minutes to obtain a chromium bonding layer;

Adjust the pressure to 0.6Pa, turn on the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode at the same time, control the current of the magnetron sputtering cathode to 0.1A and the power of 0.1kW, and the current of the magnetically adjusted multi-arc cathode to 150A and the power of 10kW, deposited on the surface of the tool drill bit for 30 minutes to obtain a high-content sp ^3- bond carbon layer;

(2) On the basis of step (1), adjust the current of the magnetron sputtering cathode to continuously increase, from 0.1A to 25A, and the current of the magnetically adjusted multi-arc cathode to continuously decrease, from 150A to 26A, and deposit for 50 minutes. Get the gradient layer;

(3) On the basis of step (2), introduce argon gas to control the pressure to 1.5Pa, and continue to control the current of the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode. The current of the magnetron sputtering cathode is 30A, and the power is 28kW, the current of the magnetically adjusted multi-arc cathode is 20A, the power is 0.2kW, the deposition is 120min, and a high-content sp ² bond carbon layer is obtained, thereby obtaining a carbon-based coating, which completely covers the drill bit area.

The tool covered with carbon-based coating in this embodiment is used to process EM390 difficult-to-machine printed circuit boards. It can process 800 holes and the processing quality meets the requirements. Compared with the tool without coating, which can only process 200 holes, the processing life is Increased to 4 times the original value.

Example 8:

This embodiment provides a method for preparing a carbon-based coating for a tool surface. The carbon-based coating is the carbon-based coating in Embodiment 3. The method includes the following steps:

(1) The tool drill bit is first ultrasonic cleaned. The cleaning media are acetone, alcohol and water. Each medium is used separately. The cleaning time is 40 minutes. After cleaning, dry it. Then place the tool drill bit in the vacuum chamber and fix it. On the fixture, evacuate until the pressure drops to 1.0×10 ^-2 Pa, and pass in argon gas to control the pressure to 0.1Pa. Turn on the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode, and control the current of the magnetron sputtering cathode. The current is 0.1A, the power is 0.15kW, the current of the magnetically adjusted multi-arc cathode is 300A, the power is 18kW, and it is deposited on the surface of the tool drill bit for 30 minutes to obtain a high-content sp ^3- bond carbon layer;

(2) On the basis of step (1), introduce argon gas to control the pressure to 0.3Pa, adjust the current gradient of the magnetron sputtering cathode to increase, first directly increase from 0.4A to 18A, and magnetically adjust the current gradient of the multi-arc cathode. The current gradient decreases, directly from 300A to 70A. After 4 minutes of deposition, the current of the adjusted magnetron sputtering cathode increases directly from 18A to 27A. The current of the magnetically adjusted multi-arc cathode decreases directly from 70A to 20A. After 16 minutes of deposition, we get: A gradient layer composed of two gradient layers;

(3) On the basis of step (2), introduce argon gas to control the pressure to 1.2Pa, and continue to control the current of the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode. The current of the magnetron sputtering cathode is 27A, and the power is 22kW, the current of the magnetically adjusted multi-arc cathode is 20A, the power is 0.5kW, and the deposition is 60 minutes to obtain a high-content sp ² bond carbon layer, thereby obtaining a carbon-based coating.

The carbon-based coating covers the peripheral edge position in the drill bit area, and then continues to deposit a low-friction coating. The low-friction coating completely covers the drill bit area. Argon gas is introduced to control the pressure to 0.1Pa to control the magnetron sputtering. The current of the ejection cathode and the magnetically adjusted multi-arc cathode is 15A and the power is 7.5kW for the magnetron sputtering cathode. The current of the magnetically adjusted multi-arc cathode is 100A and the power is 2kW. The deposition takes 20 minutes to obtain a low friction coating.

The tool covered with carbon-based coating in this embodiment is used to process EM526 difficult-to-machine printed circuit boards. It can process 700 holes and the processing quality meets the requirements. Compared with the tool without coating, which can only process 150 holes, the processing life is Increased to 4.67 times the original value.

Example 9:

This embodiment provides a method for preparing a carbon-based coating for a tool surface. The carbon-based coating is the carbon-based coating in Embodiment 4. The method includes the following steps:

(1) The tool drill bit is first ultrasonic cleaned. The cleaning media are acetone, alcohol and water. Each medium is used separately. The cleaning time is 50 minutes. After cleaning, dry it. Then place the tool drill bit in the vacuum chamber and fix it. On the fixture, evacuate until the pressure drops to 5.0×10 ^-3 Pa, and pass in neon gas to control the pressure to 3.0 Pa. Turn on the magnetically adjusted multi-arc cathode, control the current of the magnetically adjusted multi-arc cathode to 90A, and install the magnetically adjusted multi-arc cathode on the tool drill bit. Deposit on the surface for 20 minutes to obtain a chromium bonding layer; adjust the incoming gas to nitrogen, control the pressure to 3.5Pa, control the current of the magnetically adjusted multi-arc cathode to 90A, and deposit for 15 minutes to obtain a chromium nitride bonding layer;

Adjust the krypton gas pressure to 0.3Pa, turn on the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode at the same time, control the current of the magnetron sputtering cathode to 0.2A, the power to 0.05kW, and the current of the magnetically adjusted multi-arc cathode to 290A, power 17kW, continue deposition for 30 minutes, and obtain a high-content sp ^3- bond carbon layer;

(2) On the basis of step (1), adjust the current of the magnetron sputtering cathode to continuously increase from 0.1A to 25A, and continuously decrease the current of the magnetically adjusted multi-arc cathode from 290A to 30A, and deposit for 50 minutes. Get the gradient layer;

(3) On the basis of step (2), introduce krypton gas to control the pressure to 1.6Pa, and continue to control the current of the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode. The current of the magnetron sputtering cathode is 28.6A, and the power is 27.8kW, the current of the magnetically adjusted multi-arc cathode is 20A, the power is 0.9kW, and the deposition is 350min to obtain a high-content sp ² bond carbon layer, thereby obtaining a carbon-based coating, which completely covers the drill bit area.

When the tool covered with the carbon-based coating in this embodiment is used to process an aluminum-based printed circuit board, it can process 15,000 holes, and the processing quality meets the requirements. Compared with the tool not covered with the coating, which can only process 3,000 holes, the processing life is improved. to 5 times the original value.

Based on the above embodiments, it can be seen that according to the different contents of sp ³ bonds and sp ² bonds, the present invention sets carbon layers mainly composed of sp ³ bonds and sp ² bonds respectively. The former provides higher hardness and wear resistance, and the latter The friction coefficient is low and has good lubricity; the present invention sets a gradient layer between the carbon layers dominated by sp ³ bonds and sp ² bonds, so that the properties of the two can achieve a gradual transition and avoid problems caused by large differences in properties. Causes poor bonding, improves the stability of the carbon-based coating, and at the same time can reduce the internal stress in the coating, avoid the risk of easy breakage due to thickening of the coating, and achieve large-thickness deposition; the carbon-based coating and cutting tools The structure can effectively solve the processing problems of difficult-to-process high-frequency printed circuit boards, high-speed printed circuit boards, and high-performance packaging substrates, and has a wide range of applications.

The applicant declares that the present invention illustrates the detailed products and methods of the present invention through the above embodiments, but the present invention is not limited to the above detailed products and methods, that is, it does not mean that the present invention must rely on the above detailed products and methods to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements of the products of the present invention, addition of auxiliary structures, selection of specific modes, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims (10)

1. A carbon-based coating for the surface of a tool, characterized in that the carbon-based coating sequentially includes a high-content sp ³ -bond carbon layer, a gradient layer and a high-content sp ^2- bond carbon layer outward from the tool surface, The sp ³ bond content in the high-content sp 3 bond carbon layer is 50-80%, the sp ² bond content in the high-content sp ² bond carbon layer is 50-80%, and the sp ³ bond content in the gradient layer is from inside to outside. The content of ³ bonds is from high to low, and the content of sp ² bonds is from low to high. 2. The carbon-based coating according to claim 1, wherein the thickness of the high-content sp ³ bond carbon layer is 0.1 to 5 μm; Preferably, the hardness of the high-content sp ³ bond carbon layer is 45 to 65 GPa; Preferably, the thickness of the high-content sp ² bond carbon layer is 0.1 to 5 μm; Preferably, the hardness of the high-content sp ² bond carbon layer is 20 to 45 GPa; Preferably, the thickness of the gradient layer is 0.1-3 μm; Preferably, the sp ³ bond content in the gradient layer decreases from the sp ³ bond content in the high sp ³ bond carbon layer to the sp ³ bond content in the high sp ² bond carbon layer; Preferably, the sp ³ bond content or sp ² bond content in the gradient layer changes continuously or gradiently; Preferably, during the continuous gradient, the sp ³ bond content or sp ² bond content changes linearly and uniformly or nonlinearly; Preferably, during the gradient gradient, the gradient layer is composed of at least two gradient layers with different sp ³ bond contents; Preferably, the thickness of a single gradient layer is 0.02-1 μm. 3. The carbon-based coating according to claim 1 or 2, characterized in that the high-content sp ² bond carbon layer includes a pure carbon coating or an element-doped carbon coating; Preferably, the doped elements include any one or a combination of at least two of silicon, nitrogen, hydrogen, chromium, titanium, tantalum, molybdenum, niobium or aluminum; Preferably, the carbon-based coating further includes an adhesive layer, the adhesive layer is located between the carbon-based coating and the tool surface; Preferably, the material of the adhesive layer includes any one or a combination of at least two of a single substance, a corresponding simple substance nitride, a corresponding simple substance carbide, or a corresponding simple substance carbonitride; Preferably, the element includes any one or a combination of at least two of chromium, titanium, molybdenum, tungsten, tantalum, vanadium or silicon; Preferably, the number of the adhesive layer is at least one, and the thickness of each adhesive layer is 0.1 to 1 μm. 4. The preparation method of the carbon-based coating according to any one of claims 1-3, characterized in that the preparation method includes the following steps: (1) Fix the tool drill bit and then evacuate, and pass in protective gas to control the pressure, turn on the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode, control the cathode current, and deposit a high-content sp ³ bond carbon layer on the surface of the tool drill bit; (2) On the basis of step (1), the current of the magnetron sputtering cathode is continuously increased, the current of the magnetically regulated multi-arc cathode is continuously reduced, and a gradient layer is deposited; (3) On the basis of step (2), continue to control the current of the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode to deposit a high-content sp ² bond carbon layer, thereby obtaining a carbon-based coating. 5. The preparation method according to claim 4, characterized in that, in step (1), the tool drill bit is cleaned before being fixed, and the cleaning includes ultrasonic cleaning; Preferably, the medium used for cleaning includes any one or a combination of at least two of acetone, alcohol or water, and the medium is used alone; Preferably, the cleaning time is independently 10 to 60 minutes; Preferably, the tool drill bit is dried after cleaning; Preferably, the tool drill bit in step (1) is placed in a vacuum chamber and fixed on the fixture; Preferably, the pressure after vacuuming in step (1) is reduced to below 1.0×10 ^-2 Pa; Preferably, the protective gas in step (1) includes an inert gas; Preferably, the pressure after the protective gas is introduced in step (1) is 0.1 to 5 Pa; Preferably, the current of the magnetron sputtering cathode in step (1) is 0.1-2A; Preferably, the power of the magnetron sputtering cathode in step (1) is 0.05-3kW; Preferably, the current of the magnetically adjusted multi-arc cathode in step (1) is 70-300A; Preferably, the power of the magnetically adjusted multi-arc cathode in step (1) is 0.5 to 20kW; Preferably, the deposition time of the high-content sp ³ bond carbon layer in step (1) is 5 to 60 minutes. 6. The preparation method according to claim 4 or 5, characterized in that, before the high-content sp ³ bond carbon layer is deposited in step (1), an adhesive layer is deposited on the surface of the tool drill bit; Preferably, according to the different materials of the bonding layer, a magnetically adjusted multi-arc cathode is selected to control different atmosphere conditions and currents; Preferably, when the material of the adhesive layer is a single substance, the protective gas is introduced to control the pressure to be 0.1-5Pa, and the current of the magnetically adjusted multi-arc cathode is 20-300A; Preferably, when the material of the adhesive layer is a corresponding elemental nitride, nitrogen gas is introduced to control the pressure to be 0.5-5Pa, and the current of the magnetically adjusted multi-arc cathode is 20-300A; Preferably, when the material of the bonding layer is a corresponding elemental carbide, the controlled pressure of the carbon-containing gas is 0.2 to 5 Pa, and the current of the magnetically adjusted multi-arc cathode is 20 to 300 A; Preferably, when the material of the adhesive layer is a corresponding elemental carbonitride, the controlled pressure of the mixed gas containing carbon and nitrogen is 0.5-5Pa, and the current of the magnetically adjusted multi-arc cathode is 20-300A; Preferably, the carbonaceous gas includes acetylene and/or methane; Preferably, when the adhesive layer includes two or more layers, the above single layer deposition processes are combined and superimposed. 7. The preparation method according to any one of claims 4 to 6, characterized in that the current of the magnetron sputtering cathode in step (2) continues to increase from 0.1 to 2A to 20 to 30A; Preferably, the current of the magnetically regulated multi-arc cathode in step (2) is continuously reduced from 70 to 300A to 20 to 80A; Preferably, the current of the magnetron sputtering cathode and the magnetically adjusted multi-arc cathode in step (2) changes continuously or gradiently; Preferably, the deposition time of the gradient layer in step (2) is 2 to 120 minutes; Preferably, the current of the magnetron sputtering cathode in step (3) is 20-30A; Preferably, the power of the magnetron sputtering cathode in step (3) is 10 to 30kW; Preferably, the current of the magnetically adjusted multi-arc cathode in step (3) is 20-30A; Preferably, the power of the magnetically adjusted multi-arc cathode in step (3) is 0.05-1kW; Preferably, the deposition time of the high-content sp ² bond carbon layer in step (3) is 2 to 600 minutes. 8. A tool, characterized in that, the tool includes a drill bit and the carbon-based coating according to any one of claims 1-3, the drill bit includes a spiral groove, a peripheral edge and a drill tip, and the spiral groove is formed from The drill tip extends spirally toward the end of the drill bit. The carbon-based coating can be divided into three situations: completely covering the drill bit area, partially covering the drill bit area, or partially covering and then adding an overall protective layer. 9. The tool according to claim 8, wherein the drill bit has a body diameter of 0.075-6 mm; Preferably, the axial length of the spiral groove accounts for more than 80% of the length of the drill bit; Preferably, the number of said spiral grooves is at least one; Preferably, the depth of the spiral groove accounts for 5% to 52% of the diameter of the drill bit. 10. The tool according to claim 8 or 9, characterized in that the carbon-based coating completely covers the drill bit area to completely cover the spiral groove, peripheral edge and drill tip; Preferably, the carbon-based coating partially covers the drill bit area by covering the peripheral cutting edge in the drill bit area; Preferably, the length of the circumferential edge covered with the carbon-based coating accounts for 5 to 100% of the length of the spiral groove; Preferably, the partial covering followed by the overall protective layer is to cover the peripheral edge in the drill bit area and then deposit a low-friction coating as a whole; Preferably, the thickness of the low-friction coating is 0.05-0.5 μm, and the friction coefficient is less than 0.1.