A gold-colored film and a method of making the same

Abstract

The present application relates to the technical field of thin film, and in particular to a golden thin film and a preparation method thereof.The preparation method of the golden thin film comprises the following steps: depositing a functional layer on the surface of a substrate; and depositing a color layer on the surface of the functional layer away from the substrate, wherein, in the deposition process of the color layer, the reaction gas is subjected to instantaneous jump gas treatment to obtain a base piece, and the base piece is subjected to nitrogen oxide plasma treatment.In the deposition process of the color layer, the instantaneous jump gas treatment is adopted, so that the target color value can be further matched; the nitrogen oxide plasma treatment and the instantaneous jump gas treatment play a synergistic role, so that a thin film with a higher color b value can be obtained, the surface color of the thin film is consistent, and the corrosion resistance is good.

Description

Technical Field

[0001] This invention relates to the field of thin film technology, and more specifically, to a gold thin film and its preparation method. Background Technology

[0002] Currently, magnetron sputtering is a commonly used coating preparation method in PVD. Compared with traditional preparation methods such as electroplating and electroless plating, which cause serious pollution and are detrimental to environmental protection, magnetron sputtering coating technology does not require chemical solvents. It can form decorative and functional coating films on the surface of different substrates using vacuum coating technology. It has the advantages of stable process and environmentally friendly technology, making it more green and environmentally friendly. Titanium nitride (TiN) coatings are particularly widely used in magnetron sputtering. In recent years, researchers have conducted numerous studies on the preparation of titanium nitride films by magnetron sputtering, focusing on its structural morphology, corrosion resistance, and deposition of titanium nitride on different material surfaces. It is evident that titanium nitride coatings have excellent performance and have been widely used.

[0003] In the field of decorative coatings, color appearance is a particularly important indicator. The Lab color space (CIELab) is one of the most widely used color spaces, where L represents luminance, and a and b represent chromaticity coordinates (a: positive for red, negative for green; b: positive for yellow, negative for blue)). Currently, in magnetron sputtered titanium nitride decorative coating applications, the peak b value in its Lab color space (hereinafter referred to as color value) is approximately 37-38 (using a D65 light source; all color values ​​mentioned below use a D65 light source). As the requirements for the appearance of different products become increasingly demanding, the existing Lab color space values ​​of magnetron sputtered titanium nitride (TiN) are insufficient to meet the needs of some products that require higher b values ​​(i.e., a more yellow color), such as b values ​​greater than 40 or even greater than 45.

[0004] Currently, traditional magnetron sputtering processes for titanium nitride deposition primarily control the color value (Lab) of the titanium nitride film by altering the ratio between nitrogen flow rate, target sputtering power, and deposition time. However, under existing processes, regardless of whether the N2 flow rate or deposition time is increased or decreased, the peak value (b) of the resulting titanium nitride film remains around 37-39, failing to exceed the target of b>40. While interference films, utilizing optical interference principles, can achieve b>40, this color is highly sensitive to film thickness due to variations in film thickness around the 3D part.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] One object of the present invention is to provide a method for preparing a gold film that can improve the color b value of the film and improve its anti-corrosion performance.

[0007] Another objective of this invention is to provide the aforementioned gold film, which has a high color b value and good corrosion resistance.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0009] A method for preparing a gold thin film includes the following steps:

[0010] A functional layer is deposited on the surface of a substrate; a color layer is deposited on the surface of the functional layer away from the substrate. During the deposition of the color layer, the reactive gas is subjected to instantaneous gas hopping treatment to obtain a substrate, and the substrate is subjected to nitrogen oxidation plasma treatment.

[0011] In one embodiment, a first stable deposition is performed before the instantaneous gas bleed treatment, and a second stable deposition is performed after the instantaneous gas bleed treatment.

[0012] In one embodiment, the first stable deposition uses a medium-frequency magnetron sputtering power supply with a Ti target power of 3-12 kW, a working gas including argon with a flow rate of 200-800 sccm, a reaction gas including nitrogen with a flow rate of 20-100 sccm, a bias voltage of 50-400 V, and a duty cycle of 20%-80%. The first stable deposition time is 20-30 min.

[0013] In one embodiment, the instantaneous gas-skipping treatment specifically includes: increasing the flow rate of the reactant gas to 1.1 to 1.4 times the flow rate of the reactant gas in the first stable deposition within 1 second.

[0014] In one embodiment, the second stable deposition uses the reaction gas flow rate after the instantaneous gas bleed treatment, the bias voltage of the second stable deposition is greater than the bias voltage in the first stable deposition, and the time of the second stable deposition is 10 to 30 minutes.

[0015] In one embodiment, the working gas used in the nitrogen oxidation plasma treatment includes argon, nitrogen, and oxygen; the flow rate of the argon is 400–600 sccm, the flow rate of the nitrogen is 400–600 sccm, and the flow rate of the oxygen is 100–200 sccm.

[0016] In one embodiment, the bias voltage of the oxidation plasma treatment is 600–900 V, and the duty cycle is 75%–80%.

[0017] In one embodiment, the nitrogen oxidation plasma treatment specifically includes: placing the substrate in the processing chamber of the plasma processing equipment, evacuating the chamber, introducing the working gas, controlling the bias voltage to 600-750V, processing for 15-25s, then increasing the bias voltage to 750-900V, and processing for 10-20min.

[0018] In one embodiment, the functional layer includes an underlayer, the material of which includes at least one of Cr and Ti.

[0019] In one embodiment, the thickness of the underlayer is 0.1 to 1 μm.

[0020] In one embodiment, the deposition conditions for the underlayer include: using a medium-frequency magnetron sputtering power supply with a power of 3 to 12 kW; using argon as the working gas with a flow rate of 200 to 800 sccm; and using a bias voltage of 50 to 400 V and a duty cycle of 20% to 80%.

[0021] In one embodiment, when the material of the underlayer is Cr, the functional layer further includes a transition layer; the transition layer is deposited on the surface of the underlayer away from the substrate.

[0022] In one embodiment, the transition layer includes at least one of TiCrN, CrSiN, and TiSiN.

[0023] In one embodiment, the thickness of the transition layer is 0.2–1 μm.

[0024] In one embodiment, the deposition conditions of the transition layer include: using a medium-frequency magnetron sputtering power supply; a bias voltage of 50–400V and a duty cycle of 20%–80%; a Cr target power of 3–12kW and a Ti target power of 3–12kW; argon as the working gas with a flow rate of 200–800 sccm; and nitrogen as the reactant gas with a flow rate of 50–150 sccm.

[0025] In one embodiment, the material of the color layer includes TiN.

[0026] In one embodiment, the thickness of the color layer is 0.5 to 1 μm.

[0027] In one embodiment, the substrate is pre-treated with washing, heat treatment, and arc target bombardment.

[0028] In one embodiment, the heat treatment temperature is 100–130°C, and during the heat treatment process, the vacuum pressure of the environment in which the substrate is located does not exceed 8.0 × 10⁻⁶. -3 Pa.

[0029] In one embodiment, the conditions for the arc target bombardment treatment include: the working gas is argon, the flow rate of the argon is 200-800 sccm, the bias voltage is 200-600 V, the duty cycle is 20%-80%, the arc current is 40-100 A, and the treatment time is 1-10 min.

[0030] The gold film prepared by the method described above.

[0031] In one embodiment, the color values ​​of the gold film are: L = 71-73, a = 4-8, b = 40-49.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) In the deposition process of the color layer, the present invention adopts instantaneous gas jumping treatment. In this gas jumping mode, the surface of the metal target can quickly enter a more fully reactive sputtering state, and more reactant film layers can be deposited in a short time, which can further match the target color value. Further nitrogen oxidation plasma treatment of the substrate works synergistically with the instantaneous gas jumping treatment to obtain a higher color b value, which can reach 40-49 (D65 light source), making the film surface color uniform and the corrosion resistance excellent.

[0034] (2) The color values ​​of the gold film obtained by the present invention are: L = 71-73, a = 4-8, b = 40-49. The film layer is uniform and has good anti-corrosion performance. Attached Figure Description

[0035] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 These are schematic diagrams of the gold thin film in Examples 1-2 and Examples 4-5 of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the gold film in Embodiment 3 of the present invention.

[0038] Figure label:

[0039] 1-Workpiece, 2-Underlayer, 3-Transition layer, 4-Color layer. Detailed Implementation

[0040] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0041] According to one aspect of the present invention, the present invention relates to a method for preparing a gold thin film, comprising the following steps:

[0042] A functional layer is deposited on the surface of a substrate, and a color layer is deposited on the surface of the functional layer away from the substrate. During the deposition of the color layer, the reactive gas is subjected to instantaneous gas hopping treatment to obtain a substrate. The substrate is then subjected to nitrogen oxidation plasma treatment.

[0043] In the deposition process of the color layer, the present invention employs instantaneous gas hopping treatment. In this gas hopping mode, the surface of the metal target can quickly enter a more fully reactive sputtering state, and more reactant film layers can be deposited in a short time, which can further match the target color value. Further nitrogen oxidation plasma treatment of the substrate works synergistically with the instantaneous gas hopping treatment to obtain a higher color b value, which can reach 40-49 (D65 light source), making the film surface color uniform and with excellent corrosion resistance.

[0044] In one embodiment, the substrate is pre-treated with washing, heat treatment, and arc target bombardment. The present invention sequentially washes the substrate to remove dirt, oil stains, and other residual foreign matter from the workpiece surface; the substrate, after passing inspection and cleaning, is placed in a vacuum chamber for vacuuming and heat treatment. The heat treatment temperature is 100–130°C, for example, 100°C, 105°C, 110°C, 115°C, 120°C, 130°C, etc.; the vacuum pressure does not exceed 8.0 × 10⁻⁶. -3 Pa, for example 8 × 10 - 3 Pa, 7×10 -3 Pa, 6×10 -3Pa, etc. In one embodiment, the conditions for the arc target bombardment treatment include: the working gas is argon (Ar), the flow rate of the argon is 200-800 sccm, for example 200 sccm, 300 sccm, 400 sccm, 500 sccm, 600 sccm, 700 sccm, or 800 sccm, etc., the bias voltage is 200-600V, for example 200V, 300V, 400V, 500V, 600V, etc., and the duty cycle is 20%-80%, for example 20%. The arc current is 40-100A, such as 40A, 50A, 60A, 70A, 80A, 90A, 100A, etc., with a processing time of 1-10 minutes, such as 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, etc. The arc target bombardment treatment is used to activate the workpiece surface and further remove residual foreign matter from the workpiece surface.

[0045] This invention involves sequentially washing, heat treatment, and arc target bombardment of the substrate. By setting these conditions, the cleanliness of the substrate can be better ensured, the substrate surface can be activated, which is beneficial for the subsequent deposition of functional layers and ensures the connection strength between the functional layers and the substrate.

[0046] In one embodiment, the functional layer includes a base layer, the material of which includes at least one of Cr and Ti. In one embodiment, the thickness of the base layer is 0.1–1 μm, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.5 μm, 0.6 μm, 1 μm, etc.

[0047] In one embodiment, the deposition conditions for the underlayer include: using a medium-frequency magnetron sputtering power supply with a Cr target power of 3–12 kW, such as 3 kW, 4 kW, 5 kW, 6 kW, 10 kW, 12 kW, etc.; using argon as the working gas with a flow rate of 200–800 sccm, such as 200 sccm, 300 sccm, 400 sccm, 500 sccm, 600 sccm, 700 sccm, or 800 sccm, etc.; and a bias voltage of 50–400 V, such as 50 V, 80 V, 100 V, 150 V, 200 V, 250 V, 300 V, 350 V, 400 V, etc.; and a duty cycle of 20%–80%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, etc.

[0048] In one embodiment, when the material of the underlayer is Cr, the functional layer further includes a transition layer; the transition layer is deposited on the surface of the underlayer away from the substrate. When the material of the underlayer of the present invention is Cr, the adhesion between the underlayer and the color layer can be improved by depositing the transition layer. In one embodiment, the transition layer includes at least one of TiCrN, CrSiN, and TiSiN; the thickness of the transition layer is 0.2–1 μm, for example, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, etc.

[0049] Preferably, the deposition conditions of the transition layer include: using a medium-frequency magnetron sputtering power supply; the working gas is argon, and the argon flow rate is 200–800 sccm, such as 200 sccm, 250 sccm, 300 sccm, 350 sccm, 400 sccm, 500 sccm, 600 sccm, 700 sccm, 800 sccm, etc.; the reactant gas is nitrogen (N2), and the nitrogen flow rate is 50–150 sccm, such as 50 sccm, 70 sccm, 80 sccm, 100 sccm, or 1 The bias voltage is 50 sccm, etc.; the bias voltage is 50–400V, for example 50V, 80V, 100V, 120V, 150V, 200V, 300V, 400V, etc.; the duty cycle is 20%–80%, for example 20%, 30%, 40%, 50%, 60%, 70%, 80%, etc.; the Cr target power is 3–12kW, for example 3kW, 5kW, 7kW, 8kW, 10kW, 12kW, etc.; the Ti target power is 3–12kW, for example 3kW, 4kW, 5kW, 6kW, 8kW, 10kW, 12kW, etc. This invention, through the coordination of various conditions in the above-mentioned transition layer deposition, ensures the adhesion between the underlayer and the color layer, thereby improving the mechanical properties of the final film.

[0050] In one embodiment, the color layer is made of TiN. In this invention, TiN is an intrinsic color film layer, meaning the color does not change with film thickness, thus avoiding the color difference problem in 3D parts caused by using interference films to meet color requirements. In one embodiment, the thickness of the color layer is 0.5–1 μm, for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, etc.

[0051] In one embodiment, a first stabilization deposition is performed before the instantaneous gas bleed treatment, and a second stabilization deposition is performed after the instantaneous gas bleed treatment. In one embodiment, the first stabilization deposition uses a medium-frequency magnetron sputtering power source with a target power of 3–12 kW, such as 3 kW, 4 kW, 5 kW, 8 kW, 10 kW, 12 kW, etc. The working gas includes Ar with a flow rate of 200–800 sccm, such as 200 sccm, 300 sccm, 400 sccm, 500 sccm, 600 sccm, 700 sccm, 800 sccm, etc.; the reactant gas includes N2 with a flow rate of 20–100 sccm, such as 20 sccm, 30 sccm, etc. The flow rates are sccm, 40sccm, 50sccm, 60sccm, 70sccm, 80sccm, 100sccm, etc.; the bias voltage is 50-400V, such as 50V, 80V, 100V, 200V, 300V, 350V, 400V, etc.; the duty cycle is 20%-80%, such as 20%, 30%, 40%, 50%, 60%, 70%, or 80%, etc.; the first stable deposition time is 20-30min, such as 20min, 22min, 25min, 28min, 30min, etc. In one embodiment, the instantaneous gas skipping treatment specifically includes: increasing the flow rate of the reactant gas to 1.1-1.4 times the flow rate of the reactant gas for the first stable deposition within 1 second, such as 1.1 times, 1.2 times, 1.3 times, or 1.4 times, etc. In one embodiment, the second stable deposition uses the reaction gas flow rate after the instantaneous gas bleed treatment, the bias voltage of the second stable deposition is greater than the bias voltage in the first stable deposition, and the time of the second stable deposition is 10 to 30 minutes, such as 15 minutes, 16 minutes, 18 minutes, 20 minutes, 22 minutes or 25 minutes.

[0052] The present invention uses the above-mentioned deposition conditions to prepare the color layer, which is more conducive to obtaining the target color value.

[0053] In one embodiment, the working gas used in the nitrogen oxidation plasma treatment includes argon, nitrogen, and oxygen (O2). The flow rate of the argon is 400–600 sccm, for example, 400 sccm, 450 sccm, 500 sccm, 550 sccm, 600 sccm, 650 sccm, 700 sccm, 750 sccm, 800 sccm, etc. The flow rate of the nitrogen is 400–600 sccm, for example, 400 sccm, 450 sccm, 500 sccm, 550 sccm, 600 sccm, 650 sccm, 700 sccm, 750 sccm, 800 sccm, etc. The flow rate of the oxygen is 100–200 sccm, for example, 100 sccm, 120 sccm, 130 sccm, 140 sccm, 150 sccm, 160 sccm, 170 sccm, 180 sccm, 190 sccm, or 200 sccm, etc. In one embodiment, the bias voltage of the nitrogen-oxidizing plasma treatment is 600–900V, such as 600, 650V, 700V, 750V, 800V, 850V, 900V, etc., and the duty cycle is 75%–80%, such as 75%, 76%, 77%, 78%, 79%, or 80%, etc. This invention, by employing suitable flow rates of oxygen, nitrogen, and argon, and using appropriate bias voltage and duty cycle, creates a mixed gas plasma that better synergizes with the instantaneous gas hopping treatment. This allows for the acquisition of target color values, ensures uniform color on the film surface, controls the structure of the color layer, and improves its performance, such as enhancing corrosion resistance.

[0054] In one embodiment, the nitrogen oxidation plasma treatment specifically includes: opening all high-voltage valves of the equipment, and closing the bias power supply and gas flow; placing the substrate in the processing chamber of the plasma processing equipment, evacuating the chamber for 3-5 minutes, for example, 3 minutes, 4 minutes, or 5 minutes, introducing the working gas, controlling the bias voltage to 600-750V, for example, 600V, 650V, 680V, ​​700V, or 750V, processing for 15-25 seconds, for example, 15 seconds, 18 seconds, 20 seconds, 22 seconds, or 25 seconds, and then increasing the bias voltage to 750-900V, for example, 750V, 780V, 800V, 820V, 850V, 880V, or 900V, processing for 10-20 minutes, for example, 10 minutes, 12 minutes, 15 minutes, 18 minutes, or 20 minutes. The present invention employs the above-mentioned nitrogen oxidation plasma treatment conditions, which are more conducive to improving the color b value of the film and improving the physical and chemical properties of the film layer.

[0055] According to another aspect of the invention, the invention also relates to a gold film prepared by the method described above.

[0056] The color values ​​of the gold film of the present invention are: L = 71-73, a = 4-8, b = 40-49. The film layer is uniform and has good anti-corrosion performance.

[0057] The following explanation, combined with specific embodiments and comparative examples, further illustrates the point.

[0058] Example 1

[0059] A golden film, such as Figure 1 As shown, it includes a workpiece 1 and a base layer 2, a transition layer 3 and a color layer 4 sequentially stacked on the surface of the workpiece 1; wherein, the thickness of the base layer 2 is 0.5μm, the thickness of the transition layer 3 is 0.5μm, and the thickness of the color layer 4 is 0.6μm.

[0060] The method for preparing a gold thin film includes the following steps:

[0061] (1) Clean the workpiece 1 beforehand to remove dirt, oil stains and other residual foreign matter from the surface of the workpiece 1.

[0062] (2) Place the inspected and cleaned workpiece 1 into the vacuum chamber for vacuuming and preheating. The base vacuum pressure is 8.0 × 10⁻⁶. -3 Pa, the preheating temperature is 120℃.

[0063] (3) After preheating, the work gas Ar is introduced with a flow rate of 600 sccm. A bias voltage of 300 V, a duty cycle of 80%, an arc current of 60 A, and a time of 4 min are applied to the workpiece 1 to activate the surface of the workpiece 1 and further remove residual foreign matter from the surface of the workpiece 1.

[0064] (4) Cr base layer 2 is deposited on the surface of the above workpiece 1. The Cr target is connected to a medium frequency magnetron sputtering power supply, and the working gas Ar is introduced with a flow rate of 400 sccm, a bias voltage of 100V, a duty cycle of 60%, a Cr target power of 8.5kW, and a deposition time of 40min.

[0065] (5) Deposit TiCrN transition layer 3 on the above-mentioned base layer 2. The Cr target and Ti target are connected to the intermediate frequency magnetron sputtering power supply. The working gas Ar is introduced with a flow rate of 400 sccm, a bias voltage of 150V, a duty cycle of 50%, a Cr target power of 8.5kW, a Ti target power of 8kW, and a reaction gas N2 for stable deposition at 80 sccm for 30min.

[0066] (6) A TiN color layer 4 is deposited on the above transition layer 3. The Ti target is connected to a medium-frequency magnetron sputtering power supply with a target power of 8kW. The working gas Ar is introduced with a flow rate of 250sccm, the reaction gas N2 has a flow rate of 80sccm, the bias voltage is 150V, the duty cycle is 50%, and the deposition is stable for 25min. Finally, the N2 is instantaneously reduced from 80sccm to 100sccm, the bias voltage is 200V, the duty cycle is 80%, and the deposition is stable for 20min.

[0067] (7) Nitrogen oxidation plasma treatment: the high valve of the equipment is fully open, the bias voltage and gas are closed, and the furnace cavity is evacuated for 5 minutes; Ar working gas is introduced with a flow rate of 500 sccm, N2 of 600 sccm and O2 of 200 sccm, the bias voltage is set to 750V and the duty cycle is 75%, one high valve is closed, and the nitrogen oxidation plasma treatment is stabilized for 20 seconds. Then the bias voltage is increased to 900V and the duty cycle is 75%, and the nitrogen oxidation plasma treatment is stabilized for 12 minutes to obtain a gold film.

[0068] The typical color values ​​of the gold film in this embodiment are L: 71.07, a: 7.19, b: 47.01. The surface color of workpiece 1 is consistent, and the corrosion resistance is excellent. The specific performance test results are shown in Table 1 below.

[0069] Example 2

[0070] The preparation method of the gold film is the same as in Example 1, except that the flow rate of the reaction gas in step (7) of the nitrogen oxidation plasma treatment is 400 sccm for N2 and 100 sccm for O2, and the stable nitrogen oxidation plasma treatment time is 11 min.

[0071] In this embodiment, the typical color values ​​of the gold film are L: 72.4, a: 5.98, b: 43.55.

[0072] Example 3

[0073] A golden film, such as Figure 2 As shown, it includes a workpiece 1 and a base layer 2 and a color layer 4 sequentially stacked on the surface of the workpiece 1; wherein, the thickness of the base layer 2 is 0.5μm and the thickness of the color layer 4 is 0.6μm.

[0074] The method for preparing a gold thin film includes the following steps:

[0075] (1) Clean the workpiece 1 beforehand to remove dirt, oil stains and other residual foreign matter from the surface of the workpiece 1.

[0076] (2) Place the inspected and cleaned workpiece 1 into the vacuum chamber for vacuuming and preheating. The base vacuum pressure is 8.0 × 10⁻⁶. -3 Pa, preheating temperature 120℃.

[0077] (3) Perform arc target bombardment treatment, introduce working gas Ar with a flow rate of 600 sccm, and apply a bias voltage of 300V, a duty cycle of 80%, an arc current of 60A, and a time of 4min to workpiece 1 to activate the surface of workpiece 1 and further remove residual foreign matter from the surface of workpiece 1.

[0078] (4) A Ti underlayer 2 is deposited on the surface of the above workpiece 1. The Ti target is connected to a medium frequency magnetron sputtering power supply, and the working gas Ar is introduced with a flow rate of 400 sccm, a bias voltage of 100V, a duty cycle of 60%, a Cr target power of 8.5kW, and a deposition time of 40min.

[0079] (5) Deposit TiN color layer 4 on the above-mentioned base layer 2. The Ti target is connected to a medium frequency magnetron sputtering power supply with a target power of 8kW. The working gas Ar is introduced with a flow rate of 250sccm, the reaction gas N2 flow rate is 80sccm, the bias voltage is 150V, the duty cycle is 50%, and the deposition is stable for 25min. Finally, the N2 flow rate is instantaneously reduced from 80sccm to 100sccm, the bias voltage is 200V, the duty cycle is 80%, and the deposition is stable for 20min.

[0080] (6) Nitrogen oxidation plasma treatment: the high valve of the equipment is fully open, the bias voltage and gas are closed, and the furnace cavity is evacuated for 5 minutes; Ar working gas is introduced with a flow rate of 500 sccm, N2 of 600 sccm and O2 of 200 sccm, the bias voltage is set to 750V and the duty cycle is 75%, one high valve is closed, and the nitrogen oxidation plasma treatment is stabilized for 20 seconds. Then the bias voltage is increased to 900V and the duty cycle is 75%, and the nitrogen oxidation plasma treatment is stabilized for 12 minutes to obtain a gold film.

[0081] In this embodiment, the typical color values ​​of the gold film are L: 71.5, a: 6.98, and b: 46.55.

[0082] Example 4

[0083] The method for preparing a gold thin film includes the following steps:

[0084] (1) Clean the workpiece 1 beforehand to remove dirt, oil stains and other residual foreign matter from the surface of the workpiece 1.

[0085] (2) Place the inspected and cleaned workpiece 1 into the vacuum chamber for vacuuming and preheating. The base vacuum pressure is 8.0 × 10⁻⁶. -3 Pa, preheating temperature 110℃.

[0086] (3) Perform arc target bombardment treatment, introduce working gas Ar with a flow rate of 200 sccm, and apply a bias voltage of 200 V, a duty cycle of 20%, an arc current of 40 A, and a time of 3 min to workpiece 1 to activate the surface of workpiece 1 and further remove residual foreign matter from the surface of workpiece 1.

[0087] (4) Cr base layer 2 is deposited on the surface of the above workpiece 1. The Cr target is connected to a medium frequency magnetron sputtering power supply, and the working gas Ar is introduced with a flow rate of 200 sccm, a bias voltage of 50V, a duty cycle of 50%, a Cr target power of 3kW, and a deposition time of 50min.

[0088] (5) Deposit TiCrN transition layer 3 on the above-mentioned base layer 2. The Cr target and Ti target are connected to the intermediate frequency magnetron sputtering power supply. The working gas Ar is introduced with a flow rate of 200 sccm, a bias voltage of 200 V, a duty cycle of 60%, a Cr target power of 3 kW, a Ti target power of 3 kW, and a reaction gas N2 for 50 sccm deposition for 50 min.

[0089] (6) A TiN color layer 4 is deposited on the above transition layer 3. The Ti target is connected to a medium-frequency magnetron sputtering power supply with a target power of 3kW. The working gas Ar is introduced with a flow rate of 500sccm, the reaction gas N2 flow rate is 60sccm, the bias voltage is 180V, the duty cycle is 60%, and the deposition is stable for 20min. Finally, the N2 flow rate jumps from 60sccm to 70sccm, the bias voltage is 220V, the duty cycle is 80%, and the deposition is stable for 20min.

[0090] (7) Nitrogen oxidation plasma treatment: the high valve of the equipment is fully open, the bias voltage and gas are closed, and the furnace cavity is evacuated for 5 minutes; Ar working gas is introduced with a flow rate of 400 sccm, N2 of 400 sccm and O2 of 100 sccm, the bias voltage is set to 600V and the duty cycle is 50%, one high valve is closed, the nitrogen oxidation plasma treatment is stabilized for 15 seconds, then the bias voltage is increased to 800V and the duty cycle is 65%, the nitrogen oxidation plasma treatment is stabilized for 10 minutes; a gold film is obtained.

[0091] In this embodiment, the typical color values ​​of the gold film are: L: 71.98, a: 4.37, b: 41.71.

[0092] Example 5

[0093] The method for preparing a gold thin film includes the following steps:

[0094] (1) Clean the workpiece 1 beforehand to remove dirt, oil stains and other residual foreign matter from the surface of the workpiece 1.

[0095] (2) Place the inspected and cleaned workpiece 1 into the vacuum chamber for vacuuming and preheating. The base vacuum pressure is 8.0 × 10⁻⁶. -3Pa, preheating temperature 130℃.

[0096] (3) Perform arc target bombardment treatment, introduce working gas Ar with a flow rate of 800 sccm, and apply a bias voltage of 600V, a duty cycle of 80%, an arc current of 100A, and a time of 5min to workpiece 1 to activate the surface of workpiece 1 and further remove residual foreign matter from the surface of workpiece 1.

[0097] (4) Cr base layer 2 is deposited on the surface of the above workpiece 1. The Cr target is connected to a medium frequency magnetron sputtering power supply, and the working gas Ar is introduced with a flow rate of 800 sccm, a bias voltage of 200V, a duty cycle of 60%, a Cr target power of 12kW, and a deposition time of 30min.

[0098] (5) Deposit TiCrN transition layer 3 on the above-mentioned base layer 2. The Cr target and Ti target are connected to the intermediate frequency magnetron sputtering power supply. The working gas Ar is introduced with a flow rate of 800 sccm, a bias voltage of 400V, a duty cycle of 80%, a Cr target power of 12kW, a Ti target power of 12kW, and the reaction gas N2 is used for stable deposition at 80 sccm for 50min.

[0099] (6) A TiN color layer 4 is deposited on the above transition layer 3. The Ti target is connected to a medium-frequency magnetron sputtering power supply with a target power of 12kW. The working gas Ar is introduced with a flow rate of 800sccm, the reaction gas N2 has a flow rate of 50sccm, the bias voltage is 300V, the duty cycle is 70%, and the deposition is stable for 15min. Finally, the N2 flow rate jumps from 50sccm to 80sccm instantaneously, the bias voltage is 220V, the duty cycle is 80%, and the deposition is stable for 20min.

[0100] (7) Nitrogen oxidation plasma treatment: the high valve of the equipment is fully open, the bias voltage and gas are closed, and the furnace cavity is evacuated for 5 minutes; the working gas Ar is introduced with a flow rate of 600 sccm, N2 of 600 sccm and O2 of 200 sccm, the bias voltage is set to 650V and the duty cycle is 60%, one high valve is closed, the nitrogen oxidation plasma treatment is stabilized for 15 seconds, then the bias voltage is increased to 840V and the duty cycle is 75%, the nitrogen oxidation plasma treatment is stabilized for 10 minutes, and a gold film is obtained.

[0101] In this embodiment, the typical color values ​​of the gold film are: L: 71.68, a: 6.72, b: 43.24.

[0102] Comparative Example 1

[0103] The method for preparing the gold film is the same as in Example 1, except that in step (6), the flow rate of the N2 reaction gas adopts the traditional step-by-step gas addition mode, and the flow rate of the N2 reaction gas increases from 80 sccm to 100 sccm within 20 min.

[0104] In this embodiment, the typical color values of the gold film are L: 75.11, a: 6.19, and b: 36.07.

[0105] Comparative Example 2

[0106] The preparation method of the gold film is carried out according to the methods of steps (1) to (6) in Example 1.

[0107] In this comparative example, the typical color values of the gold film are L: 73.21, a: 5.12, and b: 35.01.

[0108] Comparative Example 3

[0109] The preparation method of the gold film, except that step (6) adopts the traditional step-length gas addition mode and there is no nitrogen oxide plasma treatment in step (7), and other conditions are the same as in Example 1.

[0110] This comparative example is the traditional reactive magnetron sputtering film-forming method for the TiN film layer, and its color values are L: 75.84, a: 4.12, and b: 36.51 (peak value).

[0111] Experimental Example

[0112] The gold films obtained in the above examples and comparative examples are subjected to color and performance tests. The specific tests include:

[0113] I. Color value test: After the film coating is completed, the samples are tested for L, a, and b values according to the CIE-94 standard, and the test uses D65 as the standard illuminant.

[0114] II. Cross-cut test: After the film coating is completed, use a cutting tool to draw 1mm×1mm small grids on the surface of the sample. Then, stick a fixed-type adhesive tape at the grid, and pull off the adhesive tape at a vertical angle to the sample surface, and repeat the process of sticking and pulling the adhesive tape 3 times. The adhesion is qualified if it reaches or exceeds 4B.

[0115] III. Boiling water cross-cut test: Place the samples after film coating in a constant-temperature pure water at 80°C ± 2°C for 30 minutes, and then conduct a cross-cut test. It is qualified if there is no abnormality in appearance, no obvious change (such as rust, film layer peeling, etc.), and the adhesion reaches or exceeds 4B.

[0116] IV. Vibration wear resistance: Place the samples after film coating together with ceramsite, plastic pellets, etc. in a vibration wear-resistant machine for vibration testing for 2H. It is qualified if there is no coating peeling and there are slight scratches.

[0117] V. 24H tumbling test: Place the samples after film coating together with ceramsite in a tumbling test machine for testing for 24H. It is qualified if there is no coating peeling and there are slight scratches.

[0118] 6. DMGO TEST: After the sample is coated, wipe its surface with a solution of dimethylglyoxime (DMGO). The sample is considered qualified if it does not change color to pink after the test.

[0119] 7. 72H Salt Spray Test: Place the coated sample in a salt spray test chamber with a salt concentration of 5% and a test temperature of 35℃±1℃ for 72 hours. The sample is considered qualified if there is no corrosion, spots, discoloration, discoloration, cracks, or swelling on the surface after the test.

[0120] 8. 72H Chlorine Water Immersion Test: After coating, the sample is immersed in a mixed solution of salt water and bleach for 72 hours. The sample is considered qualified if there is no corrosion, spots, discoloration, cracks, or swelling on the surface after the test.

[0121] 9. 72H High Temperature and Humidity Test: Place the coated sample in a constant temperature and humidity chamber at 85℃ and 95% for 72H. The sample is considered qualified if there is no corrosion, spots, discoloration, cracks, or swelling on the surface after the test.

[0122] The test results are shown in Table 1.

[0123] Table 1 Test Results

[0124]

[0125] As shown in Table 1, the present invention uses a combination of instantaneous gas blasting treatment and nitrogen oxidation plasma treatment to obtain a higher color b value, which can reach 41.71 to 49 (D65 light source). The film surface has a uniform color and good anti-corrosion performance.

[0126] Comparative Example 1 uses the traditional step-by-step gas injection mode, Comparative Example 2 does not undergo nitrogen oxidation plasma treatment, and Comparative Example 3 uses the traditional step-by-step gas injection mode and does not undergo nitrogen oxidation plasma treatment. The color b values ​​of the gold films obtained by Comparative Examples 1 to 3 are all low, and the target color value cannot be obtained.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a gold thin film, characterized in that, Includes the following steps: A functional layer is deposited on the surface of a substrate, and a color layer is deposited on the surface of the functional layer away from the substrate. During the deposition of the color layer, the reactive gas is subjected to instantaneous gas hopping treatment to obtain a substrate. The substrate is then subjected to nitrogen oxidation plasma treatment. A first stable deposition is performed before the instantaneous gas-dip treatment, and a second stable deposition is performed after the instantaneous gas-dip treatment; The instantaneous gas-skipping treatment specifically includes: increasing the flow rate of the reactant gas to 1.1 to 1.4 times the flow rate of the reactant gas in the first stable deposition within 1 second; The nitrogen oxidation plasma treatment specifically includes: placing the substrate in the treatment chamber of the plasma treatment equipment, evacuating the chamber, introducing working gas, controlling the bias voltage to 600~750V, treating for 15~25s, then increasing the bias voltage to 750~900V, and treating for 10~20min.

2. The method for preparing the gold thin film according to claim 1, characterized in that, The first stable deposition was performed using a medium-frequency magnetron sputtering power supply with a Ti target power of 3-12 kW, a working gas including argon with a flow rate of 200-800 sccm, a reaction gas including nitrogen with a flow rate of 20-100 sccm, a bias voltage of 50-400 V, and a duty cycle of 20%-80%. The first stable deposition time was 20-30 min.

3. The method for preparing the gold thin film according to claim 1, characterized in that, The second stable deposition uses the reaction gas flow rate after the instantaneous gas jump treatment. The bias pressure of the second stable deposition is greater than that of the first stable deposition. The time for the second stable deposition is 10~30 min.

4. The method for preparing the gold thin film according to claim 1, characterized in that, The working gases used in the nitrogen oxidation plasma treatment include argon, nitrogen, and oxygen; the flow rate of argon is 400~600 sccm, the flow rate of nitrogen is 400~600 sccm, and the flow rate of oxygen is 100~200 sccm. The duty cycle of the nitrogen oxidation plasma treatment is 75% to 80%.

5. The method for preparing a gold thin film according to claim 1, characterized in that, The functional layer includes a base layer, the material of which includes at least one of Cr and Ti.

6. The method for preparing the gold thin film according to claim 5, characterized in that, The thickness of the base layer is 0.1~1μm.

7. The method for preparing the gold thin film according to claim 5, characterized in that, The deposition conditions for the underlayer include: using a medium-frequency magnetron sputtering power supply with a Cr target power of 3~12kW; using argon as the working gas with a flow rate of 200~800sccm; a bias voltage of 50~400V and a duty cycle of 20%~80%.

8. The method for preparing a gold thin film according to claim 5, characterized in that, When the material of the underlayer is Cr, the functional layer further includes a transition layer; the transition layer is deposited on the surface of the underlayer away from the substrate.

9. The method for preparing a gold thin film according to claim 8, characterized in that, The transition layer includes at least one of TiCrN, CrSiN, and TiSiN.

10. The method for preparing a gold thin film according to claim 8, characterized in that, The thickness of the transition layer is 0.2~1μm.

11. The method for preparing a gold thin film according to claim 8, characterized in that, The deposition conditions for the transition layer include: using a medium-frequency magnetron sputtering power supply; a bias voltage of 50~400V and a duty cycle of 20%~80%; a Cr target power of 3~12kW and a Ti target power of 3~12kW; argon as the working gas with a flow rate of 200~800sccm; and nitrogen as the reactant gas with a flow rate of 50~150sccm.

12. The method for preparing a gold thin film according to claim 1, characterized in that, The material of the color layer includes TiN.

13. The method for preparing a gold thin film according to claim 1, characterized in that, The thickness of the color layer is 0.5~1μm.

14. The method for preparing a gold thin film according to claim 1, characterized in that, The substrate is pre-treated by washing, heat treatment and arc target bombardment.

15. The method for preparing a gold thin film according to claim 14, characterized in that, The heat treatment temperature is 100~130°C, and during the heat treatment process, the vacuum pressure of the environment in which the substrate is located does not exceed 8.0×10⁻⁶. -3 Pa.

16. The method for preparing a gold thin film according to claim 14, characterized in that, The conditions for the arc target bombardment treatment include: the working gas is argon, the argon flow rate is 200~800 sccm; the bias voltage is 200~600V, the duty cycle is 20%~80%, the arc current is 40~100A; and the treatment time is 1~10min.

17. The gold film prepared by the method of any one of claims 1 to 16.

18. The gold film according to claim 17, characterized in that, The color values ​​of the gold film are: L=71~73, a=4~8, b=40~49.

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