CN114000105B - A kind of preparation method of Ta-C diamond-like carbon coating and its application - Google Patents

Abstract

The application relates to the field of PCB drilling, and particularly discloses a preparation method and application of a Ta-C diamond-like coating. A preparation method of a Ta-C diamond-like coating comprises the following steps of S1, cleaning a base material; s2, putting a base material into a vacuum environment by adopting a magnetic filtration vacuum cathode arc technology, then introducing argon, opening a bias voltage, wherein the bias voltage of the base material is 550-650V, and carrying out ion bombardment for 1600-1900 s; s3, turning off argon, vacuumizing, introducing argon again, then taking a carbon target as a target material, biasing the substrate to 300-500V, setting the carbon target current to be 60-70A, and depositing for 200-350 s; s4, reducing the bias voltage of the base material to 30-60V in a gradient manner, and then continuously depositing for 1800-2100 s; and S5, cooling to obtain the diamond-like coating. The preparation method has the advantages of prolonging the service life of the micro-diameter cutter and reducing the production cost.

Description

A kind of preparation method of Ta-C diamond-like carbon coating and its application

technical field

The present application relates to the field of PCB drilling, and more particularly, to a preparation method of a Ta-C diamond-like coating and its application in a PCB micro-diameter tool.

Background technique

PCB is the abbreviation of printed circuit board. It is the support of electronic components and an indispensable basic component of all electronic information products. With the miniaturization and high speed of mobile phones, notebook computers and other products, the fine More and more attention is paid to chemical production, especially in today's 5G era, 5G products have many new requirements for signal integrity, sheet machinability and reliability to meet the needs of communication base stations, antennas, and wireless communication equipment. Design performance requirements.

In the manufacturing process of printed circuit boards, a key step is to drill through holes, which are electrical connection channels between layers and fixing or positioning holes for devices. Due to the special requirements of 5G products, the wiring density of PCB boards is getting higher and higher, and the diameter of through holes is also getting smaller and smaller, which requires the tools used for drilling through holes, such as micro-diameter drills and micro-diameter gong knives, to be smaller in size , Generally, the size of micro-diameter drill bits for PCB boards is between ¢0.1-0.25mm, and the size of micro-diameter gong knives is between ¢0.8-2.0mm.

Due to the small size of micro-diameter drill bits and micro-diameter gong knives, their service life is short. After drilling about 600 holes, they will need to be replaced due to excessive wear. Enterprises need to drill a large number of through holes to produce PCB boards, and frequently replace micro-diameter drills. Diameter tools slow down production and increase production costs.

SUMMARY OF THE INVENTION

In order to improve the service life of the micro-diameter tool and reduce the production cost, the present application provides a preparation method and application of a Ta-C diamond-like coating.

First aspect, the application provides a kind of preparation method of diamond-like coating, adopts following technical scheme:

A preparation method of Ta-C diamond-like coating, comprising the following steps:

S1. Cleaning the substrate;

S2. Using magnetic filtration vacuum cathode arc technology, the substrate is placed in a vacuum environment, and then argon gas is introduced, the vacuum chamber pressure is 0.0001~0.0003mbar, the bias voltage is turned on, and the substrate bias voltage is 550~650V, and ion bombardment is carried out. Time 1600~1900s;

S3. Turn off the argon gas, evacuate, and then pass in the argon gas, and then use the carbon target as the target material, the substrate bias is 300~500V, the carbon target current is 60~70A, and the deposition is 200~350s;

S4. Gradiently reduce the substrate bias to 30~60V, and then continue to deposit for 1800~2100s;

S5. Cool to obtain a diamond-like coating.

By adopting the above technical scheme, the substrate is covered with a Ta-C diamond-like carbon coating. The Ta-C diamond-like carbon coating is dominated by sp3 bonds, and the content of sp3 bonds is higher than 70%, so that the structural stability of the coating is high.

The substrate is etched through the S2 step to increase the contact area between the Ta-C diamond-like carbon coating and the substrate, and to improve the bonding force between the coating and the substrate. The gradient of the S4 step reduces the substrate bias, which helps to improve the The ratio of sp3 bonds in the Ta-C diamond-like carbon coating makes the coating higher in hardness and better in wear resistance, thereby improving the wear resistance of the substrate and making the size of the substrate smaller. The service life of the substrate can be increased, and it is suitable for micro-diameter tools that need to drill holes on PCB boards for many times.

Preferably, in step S2, the flow rate of argon gas is 100-150 sccm.

By adopting the above technical solution, the above-mentioned argon gas flow rate helps to control the etching degree of the substrate, thereby improving the bonding force between the Ta-C diamond-like carbon coating and the substrate.

Preferably, in step S3, the flow rate of argon gas is 5-10 sccm.

By adopting the above technical scheme, the above-mentioned argon gas flow rate helps to deposit the Ta-C diamond-like coating more uniformly, thereby improving the hardness and wear resistance of the Ta-C diamond-like coating.

Preferably, step S3 is specifically as follows: turning off argon gas, evacuation until the degree of vacuum reaches 0.0001~0.0003mbar, and then feeding argon gas, the feeding flow rate of argon gas is 5~10sccm, and adjusting the bias voltage of the substrate to 350~400V, When the vacuum degree reaches 0.042~0.050mbar, the carbon target is used as the target material, the carbon target current is 60~70A, and the deposition is 250~350s.

By adopting the above technical solution, carbon deposition is carried out after adjusting to a suitable argon atmosphere, so that the bonding force between the diamond-like carbon coating and the substrate is higher, thereby further improving the hardness and wear resistance of the coating.

Preferably, step S4 is specifically: adjusting the bias voltage to 180-250V on the substrate in step S3, depositing 200-350s, then adjusting the substrate bias to 70-150V, depositing 600-900s, and then depositing the substrate The bias voltage was adjusted to 40~60V, and then deposition was continued for 1800~2100s.

By adopting the above technical solution, the bias voltage of the substrate can be reduced in a gradient manner, and the formation rate of the diamond-like coating can be controlled within an appropriate range, thereby improving the structural stability of the diamond-like coating.

Preferably, step S4 is specifically: adjusting the bias voltage to 200~205V on the substrate in step S3, depositing 250~260s, then adjusting the bias voltage of the substrate to 95~105V, depositing 770~780s, and then depositing the substrate The bias voltage was adjusted to 40~45V, and then deposition continued for 1900~1950s.

By adopting the above technical scheme, the formation rate of the diamond-like carbon coating is further controlled, the proportion of sp3 bonds is further increased, the formation of nano-graphite crystals is restricted, and the sp3 bonds are more difficult to convert to sp2 bonds, so that the diamond-like carbon coating can still be used at high temperatures. Stable, that is, better heat resistance.

Second aspect, the application provides a kind of Ta-C diamond-like coating, adopts following technical scheme:

A Ta-C diamond-like coating, the thickness of the diamond-like coating is 0.1-0.3 μm.

By adopting the above technical solution, the thickness of the coating layer is relatively small, and the substrate can be provided with higher hardness and wear resistance without increasing the excessive thickness of the substrate.

The third aspect, the application provides a kind of application of Ta-C diamond-like coating in PCB micro-diameter cutter, adopts following technical scheme:

A kind of application of Ta-C diamond-like carbon coating in PCB micro-diameter tool, the surface of the PCB micro-diameter tool is covered with Ta-C diamond-like coating, and the PCB micro-diameter tool is a micro-diameter drill bit or a micro-diameter gong knife , the PCB micro-diameter tool is used for drilling PCB holes.

By adopting the above technical solution, the PCB micro-diameter tool is coated with a Ta-C diamond-like carbon coating, which can improve the surface hardness of the PCB micro-diameter tool and reduce the surface friction coefficient, and the Ta-C diamond-like carbon coating is suitable for the PCB micro-diameter tool. Such small-sized substrates can improve the service life of PCB micro-diameter tools and reduce costs.

To sum up, the present application has the following beneficial effects:

1. Since the application covers the Ta-C diamond-like carbon coating on the substrate, the Ta-C diamond-like carbon coating is dominated by sp3 bonds, and the sp3 bond content is higher than 70%, which makes the structural stability of the coating high; through S2 step to etch the substrate, increase the contact area between the Ta-C diamond-like carbon coating and the substrate, and improve the bonding force between the coating and the substrate; the gradient of step S4 reduces the substrate bias, which helps to improve the Ta-C The proportion of sp3 bonds in the C diamond-like coating makes the coating higher in hardness and better in wear resistance, thereby improving the wear resistance of the substrate, so that the size of the substrate can be made smaller. The service life can be improved, and it is suitable for micro-diameter tools that need to drill the PCB board many times.

2. The present application adopts the method of controlling the formation rate of the diamond-like coating, so that the diamond-like coating can still remain stable under high temperature, that is, the heat resistance is better.

Description of drawings

FIG. 1 provides a surface covered with diamond-like coating PCB micro-diameter tool provided for this application.

Marking description: 1. Substrate; 2. Ta-C diamond-like carbon coating.

Detailed ways

The present application will be further described in detail below with reference to the examples.

The cleaning solution is made up of wax removal water and degreasing agent in a volume ratio of 1:2. Both wax removal water and degreasing agent are purchased from Guangdong Hongrixing Industrial Co., Ltd., wax removal water model RS-86b, degreasing agent Model ITN-709.

Example

Example 1

An application of a Ta-C diamond-like carbon coating in a PCB micro-diameter tool, comprising a substrate 1 and a diamond-like carbon coating 2 coated on the surface of the substrate 1, wherein the substrate 1 is the PCB micro-diameter in the PCB micro-diameter tool Drills, PCB micro-diameter drills have a blade diameter of 0.2mm.

A preparation method of Ta-C diamond-like coating, comprising the following steps:

S1. Put the substrate into the cleaning solution, ultrasonic for 8min, ultrasonic frequency 28kHz.

S2. Use right-angle elbow-shaped magnetic filtration DC vacuum cathode arc deposition equipment, put the substrate into a vacuum chamber, and after the vacuum reaches 0.0001mbar, pass argon gas, and the argon gas flow rate is 100sccm, and then carry out ion bombardment. Material bias 550V, time 1600s;

S3. Turn off the argon gas, evacuate, and after the vacuum degree reaches 0.0001mbar, pass in argon gas, the flow rate of argon gas is 5sccm, while the argon gas is passed in, the carbon target is used as the target material, the substrate bias is 300V, and the carbon target current is 60A, deposition 200s;

S4. On the substrate in step S3, adjust the bias voltage to 180V, deposit 200s, then adjust the substrate bias to 70V, deposit 600s, then adjust the substrate bias to 30V, and then continue to deposit for 1800s;

S5. Cooling, after the temperature of the vacuum chamber drops below 100°C, the atmosphere is introduced, the substrate is taken out, and a Ta-C diamond-like carbon coating is obtained on the substrate, and the thickness of the Ta-C diamond-like carbon coating is 0.1 μm.

Example 2

An application of a Ta-C diamond-like carbon coating in a PCB micro-diameter tool, comprising a substrate 1 and a diamond-like carbon coating 2 coated on the surface of the substrate 1, wherein the substrate 1 is the PCB micro-diameter in the PCB micro-diameter tool Drills, PCB micro-diameter drills have a blade diameter of 0.2mm.

A preparation method of Ta-C diamond-like coating, comprising the following steps:

S1. Put the substrate into the cleaning solution, ultrasonic for 8min, ultrasonic frequency 28kHz.

S2. Use right-angle elbow-shaped magnetic filter DC vacuum cathode arc deposition equipment, put the substrate into a vacuum chamber, and after the vacuum degree reaches 0.0003mbar, pass argon gas, and the flow rate of argon gas is 150sccm, and then carry out ion bombardment. Material bias 650V, time 2100s;

S3. Turn off the argon gas, evacuate, and after the vacuum degree reaches 0.0001mbar, pass in the argon gas, the flow rate of the argon gas is 10sccm, the carbon target is used as the target material while the argon gas is passed in, the substrate bias is 500V, and the carbon target current is 70A, deposition 350s;

S4. On the substrate in step S3, adjust the bias voltage to 250V, deposit 350s, then adjust the substrate bias to 150V, deposit 900s, then adjust the substrate bias to 60V, and then continue to deposit for 2100s;

S5. Cooling, after the temperature of the vacuum chamber drops below 100° C., the atmosphere is introduced, the substrate is taken out, and a Ta-C diamond-like carbon coating is obtained on the substrate, and the thickness of the Ta-C diamond-like carbon coating is 0.29 μm.

Example 3

An application of a Ta-C diamond-like carbon coating in a PCB micro-diameter tool, comprising a substrate 1 and a diamond-like carbon coating 2 coated on the surface of the substrate 1, wherein the substrate 1 is the PCB micro-diameter in the PCB micro-diameter tool Drills, PCB micro-diameter drills have a blade diameter of 0.2mm.

A preparation method of Ta-C diamond-like coating, comprising the following steps:

S1. Put the substrate into the cleaning solution, ultrasonic for 8min, ultrasonic frequency 28kHz.

S2. Use right-angle elbow-shaped magnetic filtration DC vacuum cathode arc deposition equipment, put the substrate into a vacuum chamber, and after the vacuum reaches 0.0001mbar, pass argon gas, and the argon gas flow rate is 120sccm, and then carry out ion bombardment. Material bias 600V, time 1700s;

S3. Turn off the argon gas, evacuate, and after the vacuum degree reaches 0.0001mbar, pass in argon gas, the flow rate of argon gas is 10sccm, and the carbon target is used as the target material while passing in the argon gas, the substrate bias is 400V, and the carbon target current is 65A, deposition 250s;

S4. On the substrate in step S3, adjust the bias voltage to 250V, deposit 350s, then adjust the substrate bias to 150V, deposit 900s, then adjust the substrate bias to 60V, and then continue to deposit for 2100s;

S5. Cooling, after the temperature of the vacuum chamber drops below 100°C, the atmosphere is introduced, the substrate is taken out, and a Ta-C diamond-like carbon coating is obtained on the substrate, and the thickness of the Ta-C diamond-like carbon coating is 0.22 μm.

Example 4

The difference between this embodiment and Embodiment 3 is only that, in this embodiment, the thickness of the Ta-C diamond-like carbon coating is 0.23 μm. Step S3 is specifically as follows: turn off the argon gas, evacuate until the vacuum degree reaches 0.0001mbar, and then introduce argon gas with a flow rate of 5sccm, then adjust the substrate bias to 350V, and wait until the vacuum degree reaches 0.042mbar , with a carbon target as the target material, the carbon target current is 65A, and the deposition is 250s.

Example 5

The only difference between this embodiment and Embodiment 3 is that the thickness of the Ta-C diamond-like carbon coating is 0.22 μm. Step S3 is specifically as follows: turn off the argon gas, evacuate until the vacuum degree reaches 0.0003mbar, and then introduce argon gas with a flow rate of 10sccm, then adjust the substrate bias to the substrate bias voltage of 400V, wait for the vacuum The temperature reaches 0.050mbar, the carbon target is used as the target material, the carbon target current is 65A, and the deposition is 350s.

Example 6

The only difference between this embodiment and Embodiment 5 is that the thickness of the diamond-like carbon coating is 0.20 μm. Step S4 is as follows: adjust the bias voltage to 200V on the substrate in step S3, deposit for 250s, then adjust the substrate bias to 95V, deposit 770s, then adjust the substrate bias to 40V, and then continue to deposit for 1950s.

Example 7

The only difference between this embodiment and Embodiment 5 is that the thickness of the diamond-like carbon coating is 0.20 μm. Step S4 is as follows: adjust the bias voltage to 205V on the substrate in step S3, deposit for 260s, then adjust the substrate bias to 105V, deposit for 780s, then adjust the substrate bias to 45V, and then continue to deposit for 1900s.

Comparative ratio

Comparative Example 1

The difference between this comparative example and Example 3 is only that, in this comparative example, step S2 is specifically:

S2. Use right-angle elbow-shaped magnetic filtration DC vacuum cathode arc deposition equipment, put the substrate into a vacuum chamber, and after the vacuum reaches 0.0001mbar, pass argon gas, and the argon gas flow rate is 120sccm, and then carry out ion bombardment. The material bias is 400V, and the time is 1700s.

The steps of S3 are as follows:

S3. Turn off the argon gas, evacuate, and after the vacuum degree reaches 0.0001mbar, pass in the argon gas, the flow rate of the argon gas is 10sccm, and the carbon target is used as the target material while passing in the argon gas, the substrate bias is 600V, and the carbon target current is 65A, deposition 250s.

Comparative Example 2

The difference between this comparative example and Example 3 is only that, in this comparative example, step S4 is specifically:

The bias voltage was directly adjusted to 60V on the substrate in step S3, and then deposition was continued for 2100s.

performance test

According to YB/T 4286-2012 "Test Method for Friction Coefficient of Thin Plates and Thin Strips of Metal Materials", the friction coefficient of the coating is tested. The smaller the friction coefficient, the better the wear resistance. The test results are shown in Table 1.

According to GB/T4342-1991 "Metal Micro Vickers Hardness Test Method", the hardness of the coating was tested, and the test results are shown in Table 1.

Under the protection of argon, put the tungsten alloy with diamond-like carbon coating on the drill bit into a tube furnace, heat it to 800 ° C, keep the temperature for 30 minutes, and take it out after cooling. Test method", test the hardness of the coating after high temperature, and calculate the decay rate of the coating hardness after high temperature treatment, the calculation formula is the decay rate of coating hardness = (the hardness of the coating without high temperature treatment - the hardness of the coating treated at high temperature) / For the hardness of the coating without high temperature treatment, the smaller the coating hardness decay rate, the better the heat resistance of the coating. The test results are shown in Table 1.

Get the PCB micro-diameter drill bit covered with the Ta-C diamond-like coating obtained by the application, and get the PCB micro-diameter drill bit that does not cover the diamond-like carbon coating as a blank group, and the PCB board is drilled, and the thickness of the PCB board is 1.0mm, record the total number of drill holes before the PCB micro-diameter drill bit wears, and the test results are shown in Table 2.

Table 1

friction coefficient Coating hardness/HV Coating hardness after high temperature/HV Coating hardness decay rate/% Example 1 0.24 4551 4014 11.81 Example 2 0.22 4566 4035 11.64 Example 3 0.20 4559 4023 11.76 Example 4 0.17 4681 4154 11.26 Example 5 0.16 4676 4139 11.48 Example 6 0.13 4768 4477 6.10 Example 7 0.13 4789 4496 6.12 Comparative Example 1 0.48 3880 3394 12.52 Comparative Example 2 0.46 3727 3271 12.24

Table 2

Number of drilled holes/piece Example 1 4570 Example 2 4536 Example 3 4684 Example 4 5492 Example 5 5562 Example 6 6086 Example 7 6012 blank group 623 Comparative Example 1 2735 Comparative Example 2 2588

According to Table 1 and Table 2, it can be seen that, in combination with Example 3 and the blank group, the use of Ta-C diamond-like carbon coating to cover the micro-diameter drill bit can increase the number of drill holes of the micro-diameter drill bit, that is, the service life of the micro-diameter drill bit increases. After being covered with Ta-C diamond-like carbon coating, the surface of the micro-diameter drill has higher wear resistance.

Combined with Example 3 and Comparative Examples 1-2, the wear resistance, hardness and the number of drill holes of the diamond-like coating have all improved, indicating that the process of controlling the surface of the etching substrate, the control of the diamond-like coating and the initial coverage of the substrate surface The process and the method of reducing the bias voltage of the substrate in a gradient manner can promote the improvement of the bonding force between the diamond-like carbon coating and the surface of the substrate, and improve the structural stability of the diamond-like carbon coating, thereby improving the wear resistance and hardness.

Combined with Example 4-5 and Example 3, the wear resistance, hardness and the number of drilled holes were all improved, indicating that when the diamond-like coating is deposited, adjusting the appropriate argon atmosphere can make the diamond-like coating and the substrate. The bond strength is higher, resulting in a coating with good hardness and wear resistance.

Combined with Example 6-7 and Example 5, the wear resistance, hardness, number of drill holes and heat resistance of the coating have all improved, indicating that when the diamond-like coating is deposited, the gradient of the substrate bias is further controlled to reduce The process can make the structure formed by the diamond-like coating more stable, so as to obtain a coating with good wear resistance, hardness and heat resistance.

This specific embodiment is only an explanation of the application, and it does not limit the application. Those skilled in the art can make modifications to the embodiment without creative contribution as needed after reading this specification, but as long as the rights of the application are All claims are protected by patent law.

Claims (3)

1. A preparation method of a Ta-C diamond-like coating is characterized by comprising the following steps:

s1, cleaning a base material;

s2, putting a substrate into a vacuum environment by adopting a magnetic filtration vacuum cathode arc technology, then introducing argon, wherein the introducing flow of the argon is 100-150 sccm, the vacuum chamber pressure is 0.0001-0.0003 mbar, the bias voltage is opened, the substrate bias voltage is 550-650V, and ion bombardment is carried out for 1600-1900 s;

s3, closing argon, vacuumizing until the vacuum degree reaches 0.0001-0.0003 mbar, then introducing argon, introducing the argon at the flow rate of 5-10 sccm, adjusting the substrate to bias voltage of 350-400V, and depositing for 250-350 s when the vacuum degree reaches 0.042-0.050 mbar and the carbon target is used as a target material and the carbon target current is 60-70A;

s4, adjusting the bias voltage to 200-205V on the substrate in the step S3, depositing for 250-260S, then adjusting the bias voltage of the substrate to 95-105V, depositing for 770-780S, then adjusting the bias voltage of the substrate to 40-45V, and then continuing to deposit for 1900-1950S;

and S5, cooling to obtain the diamond-like coating.

2. A Ta-C diamond-like coating is characterized by being prepared based on the preparation method of claim 1, and the thickness of the diamond-like coating is 0.1-0.3 μm.

3. The application of the Ta-C diamond-like coating on a PCB micro-diameter cutter is characterized in that the Ta-C diamond-like coating prepared by the preparation method of claim 1 covers the surface of the PCB micro-diameter cutter, the PCB micro-diameter cutter is a micro-diameter drill bit or a micro-diameter gong cutter, and the PCB micro-diameter cutter is used for drilling a PCB.

Images