Diamond-based scratch-resistant composite substrate and its preparation method

Abstract

This invention provides a diamond-based scratch-resistant composite substrate and its preparation method. The preparation method includes the following steps: using vapor deposition technology, sequentially depositing a substrate, a seed layer, and a carbon layer onto a substrate. Before depositing the seed layer, a patterning process is used to form multiple recesses on the substrate. The composite substrate proposed in this invention features scratch resistance and good light transmittance. The preparation method of the composite substrate has good operability and repeatability, and exhibits strong adhesion to the substrate, making it suitable for applications such as mobile phone front cover panels.

Description

Technical Field

[0001] This invention applies to the field of protective coating technology, and is particularly suitable for mobile phones and tablets. Background Technology

[0002] With the development of mobile communication and mobile office, the use of smartphones and tablets is becoming increasingly widespread. A major problem with their use is that the display panels are easily scratched and subsequently shattered. Due to its extremely high hardness, diamond would be the best scratch-resistant coating for display panels.

[0003] However, existing diamond coating preparation technologies still present challenges in this application. Currently, to promote diamond nucleation and growth, substrate roughening pretreatment or the application of transition layer structures are commonly used, but both methods inevitably and significantly reduce the panel's light transmittance, thus rendering them impractical. Furthermore, if diamond is deposited directly on the display panel, the nucleation density of diamond on their surfaces is very low due to the panel's primary materials being glass and quartz, making it impossible to form an effective protective layer.

[0004] Therefore, to apply diamond coating to enhance the scratch resistance of display panels while maintaining their high light transmittance, a new technological approach is needed to overcome current technological bottlenecks. Summary of the Invention

[0005] Therefore, the present invention provides a diamond-based scratch-resistant composite substrate, the structure of which includes: a substrate, a seed layer and a carbon layer stacked sequentially, wherein a plurality of recesses are formed on the substrate for depositing the seed layer.

[0006] Preferably, the thickness of the seed layer is 2-15 nm.

[0007] Preferably, the width of the recess is 30-2000 nm.

[0008] Preferably, the spacing between adjacent recesses is 30-2000 nm.

[0009] Preferably, the seed layer is made of one or a combination of Si, Ti, Mo, and Ta.

[0010] Preferably, the carbon layer is a coating containing a diamond structure.

[0011] The present invention also provides a method for preparing the composite substrate described in any one of the above claims, comprising the following steps:

[0012] A substrate is provided, wherein the substrate is made of a high-temperature resistant material;

[0013] Multiple recesses are formed on the substrate using a patterning process;

[0014] A seed layer is deposited on the substrate and the recess;

[0015] A carbon layer is deposited on the seed layer.

[0016] Optionally, the deposition process of the carbon layer includes:

[0017] A first reactant gas, a second reactant gas, and a third reactant gas are provided. The first reactant gas is one or a combination of methane, acetone, and ethylene. The second reactant gas is hydrogen, oxygen, or hydrogen. The third reactant gas is an inert gas, including one or a combination of helium, neon, argon, and krypton.

[0018] Optionally, the flow rate ratio of the first reactant gas to the second reactant gas is 1:100 to 1:10.

[0019] Optionally, the reaction temperature for depositing the carbon layer is 600℃-1200℃, the working gas pressure is 1kPa-20kPa, and the working pulse bias voltage is 0-600V. The composite substrate proposed in this invention has the characteristics of scratch resistance and good light transmittance. The preparation method of the composite substrate has good operability and repeatability, and strong adhesion to the substrate, making it suitable for mobile phone front cover panels, etc. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a roughened surface using existing technology;

[0021] Figure 2 This is a schematic diagram of the composite substrate structure with a square recess proposed in this invention;

[0022] Figure 3 This is a schematic diagram of the composite substrate structure with a conical concave portion proposed in this invention. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and not for limiting the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, and not all of them.

[0024] The square recessed composite substrate provided in this embodiment has the following structure: Figure 2 As shown, the composite substrate includes a substrate 1a, a seed layer 101, and a carbon layer 110, wherein a plurality of recesses 100 are formed on the substrate. The seed layer 101 is located on the substrate 1a, with a portion of the seed layer 101 situated in the center of the composite substrate. The upper surface of the seed layer 101 is flush with or slightly higher than the upper surface of the substrate 1a. This seed layer facilitates diamond nucleation, thereby promoting the growth of the diamond film, and also helps improve the adhesion between the film and the substrate.

[0025] The transmittance of the composite substrate can be adjusted by regulating the seed layer structure. Specifically, by adjusting... Figure 2 The transmittance is adjusted by the width of the recess 100 and the spacing between adjacent recesses 100. The recess 100 is not limited to the structure shown in the example and can be conical, square, trapezoidal, etc. The larger the area occupied by the recess, the lower the transmittance, but it helps to improve the adhesion between the carbon layer and the substrate. Preferably, the area ratio of the plurality of recesses to the substrate is 20%-80%.

[0026] like Figure 2 As shown, the thickness of the seed layer 101 is its length in the vertical direction, flush with the recess 100, and the thickness range of the seed layer 101 is 2-15 nm. If the thickness is less than 2 nm, the carbon layer is difficult to form; if it is greater than 15 nm, the transmittance is affected. Preferably, the thickness of the seed layer is 3-10 nm.

[0027] The width of the recess 100 is 30-2000 nm. Preferably, the width of the recess 100 is 500-2000 nm. If the width of the recess 100 is greater than 2000 nm, the transmittance decreases. If the width of the recess 100 is less than 30 nm, the manufacturing difficulty is high and the process cost increases.

[0028] The spacing between adjacent recesses 100 is 30-2000 nm, preferably 100-1000 nm.

[0029] Figure 3 This is a schematic diagram of the composite substrate structure with a conical recess proposed in this invention. The cross-sectional view of the recess shows a conical structure. By adjusting the length and included angle α of the inclined surface 201 and the vertical surface 202, the transmittance of the composite substrate can be effectively controlled. The seed layer thickness, flush with the inclined surface 201 and the vertical surface 202, ranges from 2 to 15 nm, and the included angle α ranges from 20 to 150°, preferably 40 to 100°. The cone spacing is less than 2000 nm. The conical structure moves the inner seed layer to the upper surface, increasing the upper surface area of ​​the seed layer, which is beneficial for depositing a diamond film. Since the overall seed layer thickness does not increase, the light absorption of the film layer remains unchanged, i.e., the transmittance remains unchanged.

[0030] The material of the seed layer 101 includes one or a combination of Si, Ti, Mo, and Ta.

[0031] The carbon layer 110 is located on the seed layer 101, or partially on the substrate 1a.

[0032] The carbon layer 110 is a coating containing a diamond structure; specifically, the carbon layer 110 can be a diamond film or a diamond-like film. The method for preparing the composite substrate provided by this invention includes the following steps:

[0033] A substrate is provided, the substrate being a high-temperature resistant material, the substrate including but not limited to quartz glass;

[0034] Multiple recesses are formed on the substrate using a patterning process;

[0035] A seed layer is deposited on the substrate and the recess;

[0036] A carbon layer is deposited on the seed layer.

[0037] Optionally, the deposition process of the carbon layer includes:

[0038] A first reactant gas, a second reactant gas, and a third reactant gas are provided. The first reactant gas is one or a combination of methane, acetone, and ethylene. The second reactant gas is hydrogen, oxygen, or hydrogen. The third reactant gas is an inert gas, including one or a combination of helium, neon, argon, and krypton.

[0039] Optionally, the flow rate percentage of the first reactant gas and the second reactant gas is 1:10 to 1:100.

[0040] Optionally, the reaction temperature for depositing the carbon layer is 600℃-1200℃, the working gas pressure is 1kPa-20kPa, and the working pulse bias voltage is 0-600V.

[0041] Specific preparation examples

[0042] The first step is substrate cleaning, which involves sequentially using acid, alkali, acetone, alcohol, and deionized water to obtain a clean surface.

[0043] The second step is patterning, which involves using a template, exposure, development, and etching to obtain a substrate surface with multiple recesses.

[0044] The third step is to prepare the seed layer. First, the substrate surface is cleaned with Ar plasma, and then a silicon layer is deposited using vacuum deposition.

[0045] The fourth step involves preparing a carbon layer using hot-filament chemical vapor deposition. First, hydrogen, methane, and argon are introduced into the vacuum reaction chamber at flow rates of 300 sccm, 10 sccm, and 100 sccm, respectively. The working pressure is adjusted to 5 kPa. Then, the hot-filament current is slowly applied. When the substrate temperature reaches 800°C, the hot-filament current is stopped, and a substrate bias voltage of 200V is applied. Deposition is carried out for 20 minutes. The substrate bias voltage is then removed, and the filament current is slowly removed. The filament current and the reaction gas are then turned off. After the vacuum chamber cools to room temperature, the product is removed.

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A diamond-based scratch-resistant composite substrate, characterized in that, include: A substrate, a seed layer, and a carbon layer are stacked sequentially. Multiple recesses are formed on the substrate for depositing the seed layer. The seed layer has a thickness of 3-10 nm, and the area ratio of the multiple recesses to the substrate is 20%-80%. The seed layer includes filling portions filling the recesses and covering portions covering the spaces between the recesses. The material of the seed layer includes one or more combinations of Si, Ti, Mo, and Ta. The cross-sectional view of the recess is a conical structure. The length and included angle of the inclined and vertical planes of the conical structure are used to adjust the transmittance of the composite substrate. The upper surface of the seed layer is flush with or slightly higher than the upper surface of the substrate.

2. The composite substrate as described in claim 1, characterized in that, The width of the recess is 30-2000 nm.

3. The composite substrate as described in claim 1, characterized in that, The distance between adjacent recesses is 30-2000 nm.

4. The composite substrate as described in claim 1, characterized in that, The carbon layer is a coating containing a diamond structure.

5. A method for preparing a composite substrate as described in any one of claims 1-4, characterized in that, Includes the following steps: A substrate is provided, wherein the substrate is made of a high-temperature resistant material; Multiple recesses are formed on the substrate using a patterning process; A seed layer is deposited on the substrate and the recess; A carbon layer is deposited on the seed layer.

6. The method for preparing the composite substrate as described in claim 5, characterized in that, The carbon layer deposition process includes: A first reactant gas, a second reactant gas, and a third reactant gas are provided. The first reactant gas is one or a combination of methane, acetone, and ethylene. The second reactant gas is hydrogen and oxygen, or hydrogen. The third reactant gas is an inert gas, including one or a combination of helium, neon, argon, and krypton.

7. The method for preparing the composite substrate as described in claim 6, characterized in that, The flow rate percentage of the first reactant gas and the second reactant gas is 1:100-1:

10.

8. The method for preparing the composite substrate as described in claim 6, characterized in that, The reaction temperature for depositing the carbon layer is 600℃-1200℃, the working gas pressure is 1kPa-20kPa, and the working pulse bias voltage is 0-600V.

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