Part comprising plating layer and preparation method and application thereof

Abstract

The invention discloses a part comprising a plating layer as well as a preparation method and application thereof, and belongs to the technical field of CVD (Chemical Vapor Deposition) semiconductor manufacturing equipment. According to the method, the copper-based part is subjected to activating treatment, nickel plating treatment and gold plating treatment, and the part comprising the nickel plating layer and the gold plating layer is obtained; wherein the binding force of the substrate and the plating layer is remarkably enhanced, meanwhile, the aim of controlling the uniformity and the thickness of a plating layer system is achieved by controlling all technological parameters in the preparation process, and the problems that in a high-temperature and high-chemical-activity CVD reaction environment, the plating layer of a part obtained in the prior art is prone to falling off, and the plating layer is prone to falling off are solved. The performance of a reaction cavity system and the stability of a semiconductor product are influenced.

Description

Technical Field

[0001] This invention relates to the field of CVD semiconductor manufacturing equipment technology, and in particular to a part including a coating, its preparation method and application. Background Technology

[0002] The reaction chamber system of CVD (Chemical Vapor Deposition) semiconductor manufacturing equipment provides a precise, controllable, and highly clean sealed environment for semiconductor thin film deposition. The copper components within the reaction chamber system must possess excellent chemical stability, low impurity contamination, and superior surface properties to ensure high-quality semiconductor thin film deposition. Gold-plated components on copper substrates exhibit good chemical inertness, conductivity, and corrosion resistance, making them widely used in reaction chamber systems. However, gold-plated components on copper substrates prepared using existing technologies suffer from problems such as difficulty in precisely controlling the plating thickness and uniformity, and poor adhesion between the plating and the substrate. This leads to plating detachment under the high temperature and high chemical reactivity of the CVD reaction environment, thus affecting the performance of the reaction chamber system and the stability of the semiconductor products. Summary of the Invention

[0003] The main objective of this invention is to provide a part including a coating, its preparation method, and its application, aiming to solve the problems in the prior art, such as the difficulty in accurately controlling the coating thickness and uniformity, poor adhesion between the coating and the substrate, and the problem that the coating is prone to peeling off in the high-temperature, high-chemical-activity CVD reaction environment, thus affecting the performance of the reaction chamber system and the stability of semiconductor products.

[0004] To achieve the above objectives, the present invention provides a method for preparing a part including a coating, the method comprising the following steps: Activation treatment is applied to copper-based parts; The activated copper substrate part is then subjected to nickel plating to obtain a copper substrate part including a nickel plating layer. The copper substrate part, which includes a nickel plating layer, is subjected to gold plating to obtain the gold-plated part.

[0005] Optionally, before activating the copper-based part, the preparation method further includes: pretreating the copper-based part sequentially with an organic solvent, a sodium hydroxide solution, and deionized water.

[0006] Optionally, before gold plating the copper substrate part including the nickel plating layer, the preparation method further includes: annealing the copper substrate part including the nickel plating layer at 300℃~400℃ for 1h~2h under an inert atmosphere, and then immersing it in a solution containing 1%~3% sulfuric acid and 0.5%~1.0% hydrogen peroxide for 3min~5min at an immersion temperature of 25℃~35℃.

[0007] Optionally, after obtaining the part including the coating, the preparation method further includes: placing the part including the coating in a drying device and drying it at 100℃~150℃ for 1h~2h, and then immersing it in a passivation solution containing 0.5%~1.0% potassium dichromate and 3%~5% nitric acid for 2min~5min, with the immersion temperature being 25℃~35℃.

[0008] Optionally, the activation treatment of the copper substrate part includes: immersing the copper substrate part in a solution containing palladium salt and activator for 5 min to 10 min at a palladium salt concentration of 0.1 g / L to 0.5 g / L, an activator concentration of 5% to 10%, and a temperature of 30°C to 40°C.

[0009] Optionally, the composition of the plating solution in the nickel plating process includes 25 g / L to 35 g / L nickel sulfate, 20 g / L to 30 g / L sodium hypophosphite, 10 g / L to 20 g / L sodium citrate, 5 g / L to 10 g / L boric acid, a pH value of 4.5 to 5.5, a temperature of 85℃ to 95℃, and a nickel plating time of 60 min to 90 min.

[0010] Optionally, the composition of the plating solution in the gold plating process includes 3 g / L to 5 g / L potassium gold cyanide, 15 g / L to 25 g / L trisodium citrate, 5 g / L to 10 g / L potassium dihydrogen phosphate, pH value of 6.5 to 7.5, temperature of 40℃ to 50℃, pulse current density of 1 A / dm² to 3 A / dm², pulse width of 5 ms to 10 ms, pulse interval of 20 ms to 30 ms, and gold plating time of 30 min to 60 min.

[0011] To achieve the above objectives, the present invention also provides a part including a coating, wherein the part including the coating is prepared by the above-described preparation method.

[0012] Optionally, in the parts including the plating, the thickness of the nickel plating is 5μm~8μm, and the thickness of the gold plating is 0.5μm~2μm.

[0013] To achieve the above objectives, the present invention also provides an application of a part including a coating, wherein the part including a coating prepared by the above preparation method is applied to the reaction chamber system of a CVD semiconductor manufacturing equipment.

[0014] Compared with the prior art, the beneficial effects that the present invention can achieve are as follows: 1. In the technical solution of the present invention, the copper substrate parts are activated before nickel plating. This can improve the cleanliness and activity of the substrate, provide a good adhesion base for the plating layer, and thus enhance the bonding force between the substrate and the plating layer. This solves the problem in the prior art that the plating layer is easy to fall off in the high temperature and high chemical activity CVD reaction environment, which affects the performance of the reaction chamber system and the stability of semiconductor products.

[0015] 2. In the parts including the coating obtained by the present invention, the nickel coating serves as a transition layer. Before gold plating, it undergoes heat treatment and micro-etching treatment, which can further improve the bonding force between the substrate, the nickel coating and the gold coating interface, and at the same time improve the corrosion resistance and mechanical properties of the coating system.

[0016] 3. The technical solution of this invention controls the uniformity and thickness of the plating system by controlling various process parameters during the preparation process. Through post-treatment and passivation, a uniform passivation film with controllable thickness is formed on the surface of the gold plating. This not only significantly improves the discoloration and corrosion resistance of the parts, but also enhances their stability and extends their service life. It can meet the stringent requirements of the reaction chamber system of CVD (chemical vapor deposition) semiconductor manufacturing equipment for parts including plating, and improve the quality and stability of semiconductor thin film deposition. At the same time, it solves the problems of difficulty in accurately controlling the plating thickness and uniformity and poor adhesion between the plating and the substrate in the prior art. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a process for manufacturing a part including a coating. Figure 2 This is a schematic diagram of the part including the coating prepared in Example 1. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] To address the problems in existing technologies for fabricating gold-plated parts with copper substrates, such as difficulty in precisely controlling plating thickness and uniformity, and poor adhesion between the plating and the substrate, leading to plating detachment in high-temperature, highly chemically active CVD reaction environments and consequently affecting the performance of the reaction chamber system and the stability of semiconductor products, this invention provides a method for fabricating parts including plating, such as... Figure 1As shown, the preparation method includes the following steps: S10. Pre-process the copper-based parts.

[0020] Optionally, S10 above is an optional step.

[0021] Optionally, the above pretreatment method can be as follows: ultrasonically clean the copper substrate parts using an organic solvent for 15 to 30 minutes; then perform alkaline cleaning, specifically by immersing the copper substrate parts in a 5% to 10% sodium hydroxide (NaOH) solution at a temperature of 50°C to 60°C for 10 to 15 minutes, then removing them, cleaning them with deionized water, and drying them at 60°C to 80°C for 20 to 30 minutes.

[0022] Optionally, the organic solvent mentioned above can be acetone or ethanol.

[0023] It should be noted that during ultrasonic cleaning of copper-based parts using organic solvents, the strong impact force generated by the ultrasound can penetrate deep into complex structures such as crevices and blind holes, thoroughly removing attached oil and dust, thus solving the problem of dead spots encountered by manual or spray cleaning. Furthermore, during immersion in 5%~10% NaOH solution, the NaOH reacts with the oxide film on the copper surface to generate soluble sodium salts, thereby dissolving the oxide layer. Additionally, the alkaline solution can further saponify residual grease, thus removing impurities contained in the substrate. Immersion at 50℃~60℃ for 10~15 minutes can make the oxide layer dissolve more efficiently, while also enhancing solution fluidity and improving cleaning uniformity. Over-reaction should be avoided by controlling the time and temperature; if the temperature is too high or the time is too long, the strong alkali may cause slight corrosion to the copper substrate itself, damaging the surface smoothness. Therefore, precise parameter control is necessary.

[0024] S20. Activate the copper substrate part obtained in S10.

[0025] S30. The copper substrate part after activation treatment in S20 is subjected to nickel plating to obtain a copper substrate part including a nickel plating layer.

[0026] Optionally, the above-mentioned nickel plating method is electroless nickel plating.

[0027] S40. The nickel plating of the copper-based part including the nickel plating in S30 is subjected to heat treatment and micro-etching treatment in sequence.

[0028] S50. The copper substrate part with nickel plating after S40 treatment is gold plated to obtain a part with plating.

[0029] S60. The part including the coating obtained in S50 is subjected to drying and passivation treatment in sequence to obtain the part including the coating that meets the requirements.

[0030] Optionally, steps S40 and S60 above are optional.

[0031] It should be noted that in the technical solution of this invention, the copper substrate cannot be replaced with other metal substrates in the preparation method of the part including the plating layer. If the copper substrate is replaced with other metal substrates, it will directly lead to the failure of the original preparation process, or the performance of the final part will not meet the standards. Specifically, firstly, the activation treatment will fail because the original activation process is designed for the surface oxidation characteristics of copper. Other metals have different oxide layer structures and cannot be effectively activated by the system. This will cause the subsequent nickel plating layer to fail to adhere tightly, easily resulting in peeling and flaking. For example, if an iron substrate is used, the iron and nickel plating layer may form brittle intermetallic compounds during annealing or use, further damaging the bonding stability. For another example, if an aluminum substrate is used, its dense oxide film will directly block the metallurgical bonding between the plating layer and the substrate. Secondly, the pretreatment process will be mismatched. The original pretreatment is for oil stains and surface oxides on copper. However, for other metal substrates, sodium hydroxide may directly corrode their surface to form hydroxides, which will damage the substrate. For stainless steel substrates, the surface passivation film cannot be removed by the pretreatment, affecting subsequent steps. Secondly, it can lead to uncontrolled nickel or gold plating processes because the original nickel and gold plating solutions are designed based on the electrochemical activity of copper. Replacing them with other metals can result in excessively fast deposition rates or no deposition at all, making it impossible to control the thickness and uniformity of the plating layer. Thirdly, it can lead to substandard conductivity and a significant decrease in corrosion resistance in the final parts. In one possible implementation, before gold plating the copper substrate parts including the nickel plating layer, the nickel plating layer of the copper substrate parts including the nickel plating layer is subjected to heat treatment and micro-etching treatment sequentially, based on the following method: Under an inert atmosphere, copper-based parts including nickel plating are annealed at 300℃~400℃ for 1h~2h, and then immersed in a solution containing 1%~3% sulfuric acid and 0.5%~1.0% hydrogen peroxide (H2O2) for 3min~5min at an immersion temperature of 25℃~35℃.

[0032] It should be noted that before the gold plating process, the nickel plating layer is first heat-treated. This not only eliminates the internal stress of the nickel plating layer and increases its density, preventing problems such as cracking and peeling during use, but also promotes grain rearrangement, reduces porosity, and enhances corrosion resistance. Furthermore, it weakens the nickel-copper interface lattice, allowing for a tighter bond through atomic diffusion, reducing interface defects, and improving the interfacial adhesion between the nickel plating layer and the copper substrate. Simultaneously, it prevents surface fluctuations caused by stress release during subsequent processing, providing a uniform substrate for micro-corrosion treatment and stabilizing the chemical state of the nickel plating layer. Annealing at 300℃~400℃ for 1~2 hours allows for sufficient grain rearrangement within the plating layer, releasing the internal stress generated by rapid crystallization during deposition. Simultaneously, trace interdiffusion of copper and nickel atoms occurs at the interface, forming a transition layer and strengthening the interfacial bonding. Secondly, a micro-etching treatment is performed. H₂O₂, as a strong oxidant under acidic conditions, removes trace oxide and loose layers from the nickel plating surface through oxidation, selectively etching weak areas of the nickel surface to form a uniform micro-rough structure. This increases the contact area with the subsequent gold plating layer, enhancing the adhesion of the gold layer. Simultaneously, it keeps the nickel plating surface in a highly active state, avoiding uneven gold deposition caused by surface passivation during gold plating. 1%–3% sulfuric acid and 0.5%–1.0% hydrogen peroxide ensure slow and controllable etching at low concentrations. Through the synergy of temperature (25℃–35℃) and time (3 min–5 min), surface roughness ranging from nanometer to micrometer scale can be formed, rather than obvious etching, ensuring exposure of the active surface without damaging the overall plating structure.

[0033] Furthermore, the aforementioned heat treatment provides a low-stress, high-density, and high-adhesion base state for the nickel plating layer, while the micro-corrosion treatment can further purify the surface, introduce micro-roughness, and activate the interface on this basis. The combination of the two can ultimately improve the stability of the nickel plating layer and make it compatible with the subsequent gold plating process, fundamentally avoiding defects such as poor adhesion, peeling, and pinholes in the gold plating layer, ensuring the overall performance of the final plating layer (nickel + gold), and meeting the stringent requirements of the reaction chamber system of semiconductor manufacturing equipment.

[0034] In one possible implementation, the above preparation method further includes, after the gold plating process, sequentially performing a drying process and a passivation process, implemented based on the following method: After the above gold plating process, the parts with the plating layer are placed in a drying equipment and dried at 100℃~150℃ for 1h~2h. Then, they are immersed in a passivation solution containing 0.5%~1.0% potassium dichromate and 3%~5% nitric acid for 2min~5min at a immersion temperature of 25℃~35℃.

[0035] It should be noted that after the above gold plating process, a drying process is performed first. This not only removes moisture and residual plating solution adhering to the surface of the gold-plated parts, preventing the formation of crystalline impurities after moisture evaporation, but also, under heating conditions, gold and nickel atoms undergo slight diffusion at the interface. This further enhances the adhesion between the two plating layers, reduces interface gaps, and ensures the stability and uniformity of the subsequent passivation reaction. Furthermore, at 100℃~150℃, moisture can be evaporated quickly without causing oxidation of the gold plating or deterioration of the nickel plating performance due to high temperatures. Drying for 1h~2h ensures that moisture within the complex structure of the plating is fully evaporated, avoiding localized residue. Secondly, passivation treatment not only forms a dense passivation film on the gold plating surface, significantly enhancing the parts' resistance to atmospheric corrosion and minor chemical corrosion, but also prevents discoloration and corrosion of the gold plating after long-term use. Simultaneously, it fills the nanoscale pores that may be generated during the gold plating process, preventing external moisture and contaminants from penetrating to the nickel plating or copper substrate, thus avoiding underlying corrosion and keeping the gold surface in a chemically inert state. This reduces oxidation and discoloration during subsequent use and maintains stable appearance and performance. Furthermore, the nitric acid in the passivation solution is a strong oxidizing agent, which can produce a slight oxidation effect on the gold plating surface and dissolve any trace impurities that may be present, purifying the surface and promoting the passivation reaction. Potassium dichromate, a strong oxidizing passivating agent, works synergistically with nitric acid to oxidize dichromate ions (Cr2O7). 2- A reduction reaction occurs on the surface of the gold plating, producing Cr. 3+ The oxides or hydroxy oxides, together with the trace oxide layer on the gold plating surface, form an extremely thin and dense mixed passivation film. This film is chemically inert and can effectively block the erosion of oxygen, water vapor, and corrosive ions, thereby further improving the corrosion resistance of the parts. Furthermore, under the conditions of 0.5%~1.0% potassium dichromate and 3%~5% nitric acid, the passivation reaction can be ensured to be mild, forming only a nanoscale passivation film. Immersion at a temperature of 25℃~35℃ for 2min~5min not only allows for controllable reaction rate but also forms a complete passivation film. At the same time, it avoids excessive corrosion or excessively thick passivation film caused by excessive time, which could lead to problems such as the gold plating being etched thinner or the passivation film being too thick, affecting the performance of the parts.

[0036] Furthermore, the drying process provides a clean, anhydrous, and interface-stable substrate for passivation, ensuring that the passivation reaction occurs uniformly. Meanwhile, the passivation process forms a protective barrier on the surface of the gold plating. The two work together to improve the corrosion resistance of the plating, thereby adapting to the high-temperature and corrosive environment of the semiconductor reaction chamber system. This also ensures that the surface of the resulting parts, including the plating, is stable, free from impurities or oxidation risks, thus meeting the requirements of semiconductor parts for low contamination and high reliability. Moreover, the conductivity and adhesion properties of the gold plating on the parts are not affected.

[0037] In one possible implementation, the above activation process is achieved based on the following method: The copper-based part is immersed in a solution containing palladium salt and an activator for 5 to 10 minutes at a concentration of 0.1 g / L to 0.5 g / L of palladium salt, a concentration of 5% to 10% of the activator, and a temperature of 30°C to 40°C to achieve activation treatment.

[0038] Optionally, the palladium salt can be palladium chloride, and the activator can be hydrochloric acid.

[0039] In one possible implementation, the composition of the plating solution in the above-mentioned nickel plating process includes 25 g / L to 35 g / L nickel sulfate, 20 g / L to 30 g / L sodium hypophosphite, 10 g / L to 20 g / L sodium citrate, 5 g / L to 10 g / L boric acid, a pH value of 4.5 to 5.5, a temperature of 85°C to 95°C, and a nickel plating time of 60 min to 90 min.

[0040] In one possible implementation, the plating solution in the above-mentioned gold plating process comprises 3 g / L to 5 g / L potassium gold cyanide, 15 g / L to 25 g / L trisodium citrate, 5 g / L to 10 g / L potassium dihydrogen phosphate, a pH value of 6.5 to 7.5, a temperature of 40°C to 50°C, and a pulse current density of 1 A / dm³. 2 ~3A / dm 2 The pulse width is 5ms~10ms, the pulse interval is 20ms~30ms, and the gold plating time is 30min~60min.

[0041] Alternatively, when performing the gold plating process described above, a pulse electroplating process can be used.

[0042] It should be noted that the activation process described above can form uniform palladium catalytic nuclei on the copper substrate surface, providing nucleation sites for subsequent electroless nickel plating. This ensures that nickel ions can be uniformly deposited on the copper surface during electroless nickel plating, avoiding problems such as incomplete plating or uneven coating; it also prevents the copper substrate from being oxidized again before nickel plating. Furthermore, under the action of the activator, palladium ions (Pd... 2+ The palladium salt can be reduced to metallic palladium by copper, forming a layer of nanoscale and uniformly distributed palladium particles on the copper substrate surface. These palladium particles are the catalytic active centers for electroless nickel plating, catalyzing the decomposition of sodium hypophosphite and other substances to produce hydrogen atoms, which in turn reduce nickel ions and deposit them. Furthermore, by matching the palladium salt concentration to 0.1 g / L ~ 0.5 g / L, the activator concentration to 5% ~ 10%, and the temperature to 30℃ ~ 40℃, excessive agglomeration of palladium particles can be avoided, ensuring uniform dispersion of nucleation sites. At the same time, the acidic activator promotes the dissolution of palladium ions and slightly etches the copper substrate surface, increasing the adhesion sites of palladium particles, ensuring the formation of a complete catalytic layer within 5 ~ 10 minutes.

[0043] It should be noted that the above nickel plating treatment can form a uniform and dense nickel plating layer on the copper substrate surface, and the nickel plating layer has strong adhesion to the copper substrate, exhibiting good wear resistance and heat resistance. Nickel sulfate provides nickel ions (Ni... 2+ Sodium hypophosphite acts as both a reducing agent and introduces trace amounts of phosphorus into the coating, thereby improving its hardness and corrosion resistance; sodium citrate acts as a complexing agent, which can react with Ni. 2+ Formation of stable complexes, controlling Ni 2+ The release rate of boric acid can prevent excessively rapid deposition, which could lead to a loose coating. Boric acid, as a buffer, can maintain a stable pH value, ensuring a uniform reaction rate. A temperature of 85℃~95℃ ensures a stable nickel plating deposition rate while promoting grain densification. An acidic environment with a pH of 4.5~5.5 can inhibit the formation of Ni(OH)2 precipitate and promote the reaction of H2PO2. - The reduction reaction proceeds; after 60 to 90 minutes, a nickel plating layer of moderate thickness can be obtained.

[0044] It should be noted that the above gold plating process can form a uniform, bright, and high-purity gold plating layer with excellent conductivity and chemical inertness, meeting the low contact resistance requirements of semiconductor components and withstanding the high temperature and corrosive gas environment of the CVD reaction chamber. Simultaneously, the gold plating layer has strong adhesion to the nickel substrate, without pinholes, peeling, or other defects, thus avoiding substrate corrosion or contaminant release problems caused by plating failure. During the electroplating process, potassium gold cyanide can provide Au. + High stability to ensure Au + Uniform deposition; trisodium citrate, as a complexing agent, can adjust the dispersion ability of the plating solution and improve the uniformity of the coating; potassium dihydrogen phosphate, as a buffer, can maintain a neutral environment with a pH of 6.5~7.5, avoiding cyanide decomposition or gold ion hydrolysis. At a pulse current density of 1 A / dm³... 2 ~3A / dm 2 With a pulse width of 5ms to 10ms and a pulse interval of 20ms to 30ms, concentration polarization can be reduced, resulting in a more uniform and dense coating. Furthermore, a short pulse width can reduce the formation of coarse grains, while a long interval can reduce the internal stress of the coating, preventing cracking. In addition, the control of time and temperature can promote ion diffusion and regulate the coating thickness.

[0045] Furthermore, because of the significant potential difference between copper and gold, directly plating gold on a copper substrate may trigger displacement reactions such as copper dissolution or gold deposition, resulting in a porous plating layer. Moreover, under high-temperature conditions, copper easily diffuses into the gold layer, damaging its properties. In the technical solution of this invention, the nickel plating layer serves as a transition layer, acting as a barrier and providing a stable substrate for the gold plating layer.

[0046] Furthermore, during the aforementioned nickel plating process, if the concentration of nickel sulfate is <25 g / L, it will lead to Ni... 2+ Insufficient supply leads to slow deposition rates and the coating is prone to pinholes and uneven thickness; if the concentration is >35g / L, then Ni 2+ It easily forms precipitates with other ions, leading to decreased plating solution stability and coarse, loose grains in the coating; while a concentration range of 25 g / L to 35 g / L can ensure Ni 2+ A continuous and stable supply, a moderate deposition rate, and uniform coating composition.

[0047] Sodium hypophosphite, as a reducing agent, will result in insufficient reducing power, slow deposition rate, low phosphorus content in the coating, and decreased corrosion resistance and hardness if the concentration is <20 g / L. If the concentration is >30 g / L, it will decompose excessively and generate a large number of bubbles. These bubbles will adhere to the surface of the parts and cause pinholes in the coating. At the same time, the introduction of excessive phosphorus will increase the brittleness of the coating. The concentration range of 20 g / L to 30 g / L can ensure that the rate of reduction reaction is matched with the deposition of nickel ions, resulting in a moderate phosphorus content in the coating and reducing the probability of coating defects.

[0048] Sodium citrate acts as a complexing agent, reacting with Ni 2+ Combined to form stable complexes, controlling free Ni 2+ The concentration should be carefully controlled to prevent excessive reduction that could lead to a porous coating; if the concentration is <10 g / L, insufficient complexation will result in insufficient free Ni. 2+ Excessive concentration or excessively rapid deposition rate can lead to dendrite formation and high porosity in the coating. Concentrations exceeding 20 g / L can result in over-complexation, leading to the release of free Ni. 2+ The drawback is that the deposition rate drops sharply, and the viscosity of the plating solution increases, affecting ion diffusion and reducing coating uniformity; while a concentration range of 10 g / L to 20 g / L allows for precise control of free Ni. 2+ The concentration makes the deposition reaction mild and orderly, and the coating grains are refined and the density is improved.

[0049] Boric acid, when used as a buffer, will have insufficient buffering capacity if its concentration is <5 g / L, leading to OH- ions generated during the reaction. - If the concentration is greater than 10 g / L, boric acid crystals will precipitate out, contaminating the plating solution and scratching the coating. However, a concentration range of 5 g / L to 10 g / L, at a reaction temperature of 85℃ to 95℃, can stably maintain a stable pH value, ensuring the consistency of reaction rate and coating quality.

[0050] Furthermore, in the nickel plating solution, the ratio of nickel sulfate to sodium hypophosphite is approximately 1.2:1, which ensures the Ni... 2+The balance between reduction and reducing agent consumption avoids deposition interruptions caused by an excess of nickel ions and a shortage of reducing agent, or excessive gas production caused by an excess of reducing agent and a shortage of nickel. The ratio of sodium citrate to nickel sulfate is close to 0.5:1, ensuring that the amount of complexing agent is appropriately matched to the Ni content. 2+ Concentration can prevent free Ni 2+ An excess of Ni can ensure that the reduction reaction has enough Ni. 2+ Supply enables slow and steady nickel plating deposition.

[0051] Furthermore, in the above-mentioned gold plating process, potassium gold cyanide in the plating solution acts as Au. + A stable source of Au; if the concentration is <3 g / L, it will lead to Au. + Insufficient supply and pulse deposition can easily lead to uneven coating thickness and slow deposition rate due to concentration polarization; if the concentration is >5 g / L, Au will appear. + Excessive concentration leads to excessively rapid reduction, resulting in nodules and roughness in the coating, increasing costs; while a concentration range of 3g / L to 5g / L, matched and synergistic with the pulse current parameters, ensures the Au... + Sufficient diffusion and replenishment during the pulse intervals result in a coating with uniform thickness and high purity.

[0052] Trisodium citrate, as an auxiliary complexing agent and conductive salt, can enhance the dispersibility and conductivity of the plating solution. If the concentration is <15 g / L, insufficient dispersibility will result in incomplete plating or an excessively thin coating. Poor conductivity will lead to uneven pulse current distribution and a rough coating. If the concentration is >25 g / L, the viscosity of the plating solution will increase, and Au... + Increased diffusion resistance leads to a decrease in deposition rate, and excessive citrate ions may adsorb onto the gold layer surface, affecting conductivity. However, a concentration range of 15 g / L to 25 g / L can optimize the dispersion ability and conductivity of the plating solution, ensuring that gold ions are uniformly reduced on the surface of the part during pulse electroplating, resulting in a bright, uniform, and smooth plating layer.

[0053] Potassium dihydrogen phosphate, as a buffer, has insufficient buffering capacity if the concentration is <5 g / L, leading to easy pH fluctuations during electroplating; if the concentration is >10 g / L, it will introduce excess potassium. + It may form crystals with other ions, contaminating the plating solution and causing particle defects in the coating; while a concentration range of 5 g / L to 10 g / L can stabilize the pH in the neutral range, ensuring the stability of the gold cyanide complex ions, while avoiding interference from impurity ions and ensuring the purity of the gold layer.

[0054] Furthermore, in the gold plating solution, the ratio of potassium gold cyanide to trisodium citrate is approximately 1:5, which allows Au... +Under pulsed current, it migrates uniformly to the nickel substrate surface, avoiding coating defects caused by excessively high local concentrations. Potassium dihydrogen phosphate, through synergistic action with the overall system, maintains a neutral pH environment, ensuring that potassium gold cyanide does not decompose and gold ions do not hydrolyze. Simultaneously, it provides suitable ionic strength for trisodium citrate, ensuring its dispersion and conductivity. Meanwhile, 3 g / L ~ 5 g / L of Au... + Concentration and 1A / dm 2 ~3A / dm 2 The pulse current density is coordinated to achieve Au within a pulse width of 5ms to 10ms. + Rapid reduction, while the 20ms~30ms pulse interval replenishes Au through the dispersing effect of trisodium citrate. + This avoids concentration polarization and ultimately forms a uniform and dense gold layer.

[0055] To achieve the above objectives, the present invention also provides a part including a coating, wherein the part including the coating is prepared by the above-described preparation method.

[0056] In one possible implementation, in the above-mentioned parts including the plating, the thickness of the nickel plating is 5μm to 8μm, and the thickness of the gold plating is 0.5μm to 2μm.

[0057] It should be noted that the parts prepared by the above method, including the coating, possess excellent corrosion resistance, high conductivity, and stability; the coating interfaces exhibit good mechanical properties and adhesion. In the technical solution of this invention, during the nickel plating process, by setting the concentration of each component in the plating solution and the process parameters of the coating deposition process, the reduction rate of nickel ions can be ensured to be stable and controllable. Simultaneously, sodium citrate in the plating solution can avoid fluctuations in the reduction rate and ensure the consistency of the coating thickness within the same time period. Secondly, during the gold plating process, the magnitude of the pulse current density determines the amount of gold ions reduced per unit area, and temperature promotes ion diffusion. Through the synergistic use of current density, plating time, and temperature parameters, the thickness and uniformity of the gold plating layer are jointly ensured. Furthermore, in the preparation process of parts including the coating, by synergistically controlling the parameters of the entire process—pretreatment of the copper substrate, activation treatment, nickel plating, micro-corrosion, and gold plating—the thickness of both the nickel and gold plating layers can be precisely controlled, and the uniformity of each stage can be adjusted to ensure stable coating quality. Ultimately, the corrosion resistance, conductivity, and adhesion of the parts all meet the stringent requirements of semiconductor devices.

[0058] To achieve the above objectives, the present invention also provides an application of a part including a coating, wherein the part including a coating prepared by the above method is applied to the reaction chamber system of a CVD semiconductor manufacturing equipment.

[0059] CVD reaction chamber systems are exposed to corrosive gases such as hydrogen chloride, ammonia, and fluorides during operation, accompanied by high temperatures. The parts prepared using this invention feature a coating that forms a dual anti-corrosion barrier. Specifically, the dense Ni / P alloy layer in the nickel plating completely isolates the copper substrate from corrosive gases, preventing copper oxidation or the formation of soluble salts that could lead to part failure, thus ensuring tolerance to the corrosive environment of the reaction chamber. The gold plating prevents the nickel layer from oxidizing during long-term use. Simultaneously, the passivation treatment forms a Cr2O3-Au2O3 mixed film that seals the micropores of the gold layer, further reducing corrosive media penetration and extending the part's lifespan. The parts prepared using this invention have a coating purity greater than 99.9%, release no volatiles at high temperatures, and have a smooth surface that does not adhere to CVD reaction byproducts, maintaining a high level of cleanliness in the reaction chamber and preventing contamination of the semiconductor thin film. In CVD processes, the reaction chamber temperature needs to be frequently switched. Temperature cycling can easily lead to cracking and coating peeling of parts due to differences in thermal expansion coefficients. However, the coating of the parts prepared by this invention can adapt to the temperature fluctuations of the reaction chamber and ensure structural stability. Furthermore, the electroless nickel plating and pulsed gold plating processes can improve the surface smoothness of the parts, allowing them to adhere tightly to other parts and ensuring the sealing of the reaction chamber. In summary, this invention, through the control of process steps and parameters, produces parts with a long service life, improves the quality of semiconductor thin films, and stabilizes the process parameters of the reaction chamber system.

[0060] Example 1 A method for preparing a part including a coating includes the following steps: S10. Pre-treat the copper-based parts by immersing them in acetone solution and ultrasonically cleaning them for 15 minutes to remove oil and impurities from their surface; then immerse them in 10% NaOH solution at 50°C for 15 minutes, then remove them, rinse them with deionized water, and place them in an oven to dry at 60°C for 20 minutes. S20. Activate the copper substrate parts obtained in S10 by immersing them in a solution containing 0.1 g / L palladium chloride and 10% hydrochloric acid at 30°C for 10 min. S30. The copper substrate parts activated by S20 are subjected to nickel plating. The activated copper substrate parts are placed in a plating solution containing 25 g / L nickel sulfate, 20 g / L sodium hypophosphite, 10 g / L sodium citrate and 5 g / L boric acid. The pH value is adjusted to 4.5, the temperature is maintained at 85℃, and the nickel plating is completed after 90 min. The thickness of the nickel plating layer is about 6 μm. During the S30 nickel plating process, under the action of a palladium catalyst, sodium hypophosphite decomposes to generate active hydrogen, reducing nickel ions to metallic nickel, which is then deposited on the surface of the copper substrate to form a nickel plating layer. In the acidic plating solution, Ni... 2+ It coexists in both free and complexed (bound to sodium citrate) states, continuously migrating to the substrate surface via diffusion, providing the material basis for the reduction reaction. When the nickel sulfate concentration is 25 g / L, the supply of nickel ions and the reduction rate are matched. If the concentration is lower than 25 g / L, it will lead to... 2+ Insufficient supply of sodium hypophosphite has led to problems such as interrupted nickel plating deposition and sparse plating. Sodium hypophosphite, as a reducing agent, can decompose under palladium catalysis and at 85°C: H₂PO₂. - + H2O → H + + HPO3 2- + 2 [H] (active hydrogen), the active hydrogen further reduces Ni 2+ Ni 2+ + 2[H] → Ni↓ + 2H + Simultaneously, some hypophosphate ions are oxidized to phosphate ions, introducing trace amounts of phosphorus into the coating (forming a Ni / P alloy), which can improve the corrosion resistance and hardness of the coating. Sodium citrate, as a complexing agent, can not only control the Ni content... 2+ The reduction rate is controlled, preventing excessively rapid reactions that could lead to coarse grains and increased porosity in the coating. Furthermore, it can adsorb onto the coating surface, inhibiting dendrite growth and resulting in a more uniform and dense coating, significantly improving the uniform plating performance, especially for complex-shaped parts. Secondly, during nickel plating, if the pH value is <4.5, excessive acidity will inhibit the decomposition of sodium hypophosphite, leading to reduced active hydrogen generation and a decreased deposition rate. Simultaneously, high pH... + It will etch the copper substrate, leading to a decrease in the adhesion between the plating and the substrate; if the pH is greater than 5.5, the increased alkalinity will cause Ni to... 2+ With OH - The formation of Ni(OH)₂ precipitate causes the plating bath to become turbid, resulting in particle defects in the coating. Simultaneously, the excessively rapid decomposition of sodium hypophosphite generates numerous bubbles, increasing the porosity of the coating. Furthermore, temperatures below 85℃ lead to slow ion diffusion, resulting in fine but poorly dense grains in the coating; temperatures above 95℃ result in excessively rapid reaction rates, making the coating prone to scorching, while also reducing the stability and lifespan of the plating bath and increasing energy consumption. If the nickel plating time is less than 90 minutes, a 6μm thick nickel coating cannot be formed under the set conditions, failing to meet the requirements of the CVD corrosion environment.

[0061] As can be seen from the above analysis, in the nickel plating process of the present invention, there is a synergy between the types of components, the concentration of components and the nickel plating parameters, and the technologies are a unified whole that cannot be separated. If any of the conditions are changed or replaced, it will be difficult to achieve the purpose and technical effect of the present invention.

[0062] S40. The nickel plating of the copper substrate part including the nickel plating in S30 is subjected to heat treatment and micro-etching treatment in sequence. The copper substrate part including the nickel plating is placed in a nitrogen atmosphere furnace and annealed at 300°C for 2 hours for heat treatment; then it is immersed in a solution containing 1% sulfuric acid and 0.5% hydrogen peroxide (H2O2) for 5 minutes and kept at 25°C for micro-etching.

[0063] S50. Gold plating is performed on the copper substrate part with nickel plating obtained after S40 treatment. Using the copper substrate part with nickel plating obtained in S40 as the cathode and a high-purity gold plating plate as the anode, pulse electroplating is employed. The plating solution contains 3 g / L potassium gold cyanide, 15 g / L trisodium citrate, and 5 g / L potassium dihydrogen phosphate. The pH is adjusted to 6.5, and the plating solution temperature is maintained at 40°C. The pulse current density is set to 1 A / dm³. 2 With a pulse width of 5ms and a pulse interval of 20ms, a gold plating layer with a thickness of approximately 1μm was obtained after 60 minutes. During the gold plating process, gold ions exist in a stable complex state Au(CN)2. - Gold ions migrate towards the negatively charged working electrode (cathode) surface under the influence of an electric field. Upon reaching the surface, they gain electrons and are reduced, depositing as atoms on the nickel plating surface, gradually forming a gold plating layer. During this stage, the auxiliary complexation effect of trisodium citrate ensures uniform distribution of gold ions, preventing excessively high local concentrations that could lead to a rough plating layer. During the pulse interval, the power supply is paused, stopping the reduction reaction of gold ions. At this time, undeposited gold ions in the plating solution diffuse to the cathode surface, preparing for uniform deposition of the gold plating layer in the next conduction period. Simultaneously, the interval reduces internal stress in the plating layer. Continuous power supply and rapid ion reduction can easily lead to coarse grains and increased internal stress, while the interval allows the deposited gold atoms time to rearrange, resulting in a denser gold plating layer. Furthermore, a plating solution pH of 6.5 and an electroplating temperature of 40°C provide suitable conditions for the electrode reaction. If the pH is less than 6.5, CN... - It easily generates highly toxic HCN gas and affects anodic dissolution; if the temperature is <40℃, it will reduce the electrode reaction efficiency and lead to a decrease in the deposition rate.

[0064] S60. The parts including the coating obtained in S50 are dried and passivated. The parts are placed in an oven and dried at 100°C for 2 hours. Then they are immersed in a passivation solution containing 0.5% potassium dichromate and 3% nitric acid for 5 minutes, and the temperature of the passivation solution is maintained at 35°C.

[0065] Through steps S10 to S60, parts including the coating that meet the requirements are obtained.

[0066] A schematic diagram of the resulting part including the plating is shown below. Figure 2 As shown. Figure 2 As can be seen, the surface of the part prepared in Example 1 is smooth and flat, and the gold plating layer is tightly adhered.

[0067] The resulting parts, including the coating, are applied to the reaction chamber system of a CVD semiconductor manufacturing equipment.

[0068] The uniformity of the coating on the parts including the coating obtained in Example 1 was measured. It was found that the difference between the maximum and minimum thickness of the coating was ≤ 5% of the average thickness, indicating excellent uniformity. No local exposure of copper or nickel was found.

[0069] Example 2 A method for preparing a part including a coating includes the following steps: S10. Pre-treat the copper-based parts by immersing them in acetone solution and ultrasonically cleaning them for 30 minutes to remove oil and impurities from their surface; then immerse them in 15% NaOH solution at 60°C for 10 minutes, then remove them, rinse them with deionized water, and place them in an oven to dry at 90°C for 30 minutes. S20. Activate the copper substrate parts obtained in S10 by immersing them in a solution containing 0.5 g / L palladium chloride and 5% hydrochloric acid at 40°C for 5 min. S30. The copper substrate parts activated by S20 are subjected to nickel plating. The activated copper substrate parts are placed in a plating solution containing 35 g / L nickel sulfate, 30 g / L sodium hypophosphite, 20 g / L sodium citrate and 10 g / L boric acid. The pH value is adjusted to 5.5, the temperature is maintained at 95℃, and the nickel plating is completed after 60 min. The thickness of the nickel plating layer is about 7 μm. In S30, at 95°C, if the concentration of nickel sulfate is <35 g / L, a 7 μm thick nickel plating layer cannot be formed within 60 minutes; if the concentration is >35 g / L, then Ni... 2+ Easy to react with OH - The formation of Ni(OH)2 precipitate contaminates the plating bath and leads to particulate impurities in the coating. However, the synergistic effect of 30 g / L sodium hypophosphite and a temperature of 95°C provides sufficient H2PO2. -To ensure the continuous and efficient progress of the reduction reaction, if the concentration is <30g / L, insufficient active hydrogen generation will occur at 95℃, significantly reducing the deposition rate and leading to insufficient coating thickness, decreased phosphorus content, and reduced corrosion resistance. If the concentration is >30g / L, excessive decomposition will generate a large number of H2 bubbles, which will adhere to the surface of the parts, forming pinholes. Furthermore, the increased phosphorus content in the coating will increase brittleness and cause cracks. Secondly, sodium citrate, in synergy with 35g / L nickel sulfate and a pH of 5.5, precisely controls the free Ni... 2+ Concentration allows for controllable reaction rates and refined coating grains; if the concentration of sodium citrate is <20 g / L, its complexing ability will be insufficient, leading to the release of free Ni. 2+ Significantly increased concentration leads to dendrite formation in the coating, and excessively thick deposition is prone to occur at blind holes in complex parts due to the tip effect; if the concentration is >20 g / L, it will cause excessive complexation, resulting in free Ni 2+ Insufficient concentrations lead to reduced deposition efficiency, increased plating solution viscosity, hindered ion diffusion, and decreased coating density. Furthermore, 10 g / L boric acid, combined with pH=5.5 and a temperature of 95°C, provides strong buffering capacity, keeping pH fluctuations within ±0.1. If the boric acid concentration is <10 g / L, insufficient buffering capacity occurs, inhibiting sodium hypophosphite decomposition, resulting in large fluctuations in deposition rate and uneven coating thickness. If the concentration is >10 g / L, exceeding the solubility at 95°C, boric acid crystallizes and precipitates, scratching the coating surface and clogging the circulating filtration system, affecting plating solution stability. Therefore, in the technical solution of this invention, under the set conditions of the nickel plating process, the types and concentrations of components, as well as the nickel plating parameters, cannot be replaced or omitted. All technical features are integrated and synergistic, working together to achieve the purpose of this invention.

[0070] S40. The nickel plating of the copper substrate part including the nickel plating in S30 is subjected to heat treatment and micro-etching treatment in sequence. The copper substrate part including the nickel plating is placed in a nitrogen atmosphere furnace and annealed at 400°C for 1 hour for heat treatment; then it is immersed in a solution containing 3% sulfuric acid and 1.0% hydrogen peroxide (H2O2) for 3 minutes and kept at 35°C for micro-etching.

[0071] S50. Gold plating is performed on the copper substrate part with nickel plating obtained after S40 treatment. Using the copper substrate part with nickel plating obtained in S40 as the cathode and a high-purity gold plating plate as the anode, pulse electroplating is employed. The plating solution contains 5 g / L potassium gold cyanide, 25 g / L trisodium citrate, and 10 g / L potassium dihydrogen phosphate. The pH is adjusted to 7.5, and the plating solution temperature is maintained at 50°C. The pulse current density is set to 3 A / dm³. 2 With a pulse width of 10ms and a pulse interval of 20ms, a gold plating layer with a thickness of approximately 2μm was obtained after 30 minutes. During the gold plating process, a pH of 6.5 and an electroplating temperature of 40°C provide suitable conditions for the electrode reaction. If the pH is less than 6.5, then CN... - It easily generates highly toxic HCN gas and affects anodic dissolution; if the temperature is <40℃, it will reduce the electrode reaction efficiency and lead to a decrease in the deposition rate.

[0072] S60. The parts including the coating obtained in S50 are dried and passivated. The parts are placed in an oven and dried at 150°C for 1 hour. Then they are immersed in a passivation solution containing 1.0% potassium dichromate and 5% nitric acid for 2 minutes, and the temperature of the passivation solution is maintained at 25°C.

[0073] Through steps S10 to S60, parts including the coating that meet the requirements are obtained.

[0074] The resulting parts, including the coating, are applied to the reaction chamber system of a CVD semiconductor manufacturing equipment.

[0075] Example 3 A method for preparing a part including a coating includes the following steps: S10. Pre-treat the copper-based parts by immersing them in acetone solution and ultrasonically cleaning them for 30 minutes to remove oil and impurities from their surface; then immerse them in 15% NaOH solution at 60°C for 10 minutes, then remove them, rinse them with deionized water, and place them in an oven to dry at 90°C for 30 minutes. S20. Activate the copper substrate parts obtained in S10 by immersing them in a solution containing 0.3 g / L palladium chloride and 7% hydrochloric acid at 35°C for 8 min. S30. The copper substrate parts activated by S20 are subjected to nickel plating. The activated copper substrate parts are placed in a plating solution containing 30 g / L nickel sulfate, 25 g / L sodium hypophosphite, 15 g / L sodium citrate and 7 g / L boric acid. The pH value is adjusted to 5.0, the temperature is maintained at 90℃, and the nickel plating process is completed after 80 min. The thickness of the nickel plating layer is about 6 μm. S40. The nickel plating of the copper substrate part including the nickel plating in S30 is subjected to heat treatment and micro-etching treatment in sequence. The copper substrate part including the nickel plating is placed in a nitrogen atmosphere furnace and annealed at 350°C for 1.5h for heat treatment; then it is immersed in a solution containing 2% sulfuric acid and 0.8% H2O2 for 4min and kept at 30°C for micro-etching. S50. Gold plating is performed on the copper substrate part with nickel plating obtained after S40 treatment. Using the copper substrate part with nickel plating obtained in S40 as the cathode and a high-purity gold plating plate as the anode, pulse electroplating is employed. The plating solution contains 4 g / L potassium gold cyanide, 20 g / L trisodium citrate, and 7 g / L potassium dihydrogen phosphate. The pH is adjusted to 7.0, and the plating solution temperature is maintained at 45°C. The pulse current density is set to 2 A / dm³. 2 With a pulse width of 7ms and a pulse interval of 15ms, a gold plating layer with a thickness of approximately 1.5μm was obtained after 50 minutes.

[0076] S60. The parts including the coating obtained in S50 are subjected to drying and passivation treatment in sequence. The parts are placed in an oven and dried at 120°C for 1.5 hours. Then, they are immersed in a passivation solution containing 0.8% potassium dichromate and 4% nitric acid for 3 minutes, and the temperature of the passivation solution is maintained at 30°C.

[0077] Through steps S10 to S60, parts including the coating that meet the requirements are obtained.

[0078] The resulting parts, including the coating, are applied to the reaction chamber system of a CVD semiconductor manufacturing equipment.

[0079] The mechanical properties (coating adhesion and coating hardness), chemical properties (acid corrosion resistance and oxidation resistance), functional properties (conductivity and sealing surface smoothness), and cleanliness (surface particle count and metal impurity content) of the parts including the coatings obtained in Examples 1 to 3 were measured respectively, and the results are shown in Table 1.

[0080] Table 1

[0081] As shown in Table 1, the coating adhesion of the parts prepared in Examples 1-3, including the coated parts, can all reach a coating hardness of 5B or higher, and the coating hardness is high. Furthermore, no corrosion defects were observed after passing through salt spray and acid corrosion tests. This is because the dense barrier effect of the nickel coating and the chemical inertness of the gold coating, combined with the Cr2O formed by the passivation treatment, contribute to the overall effect. 3- Au2O3 protective film can effectively resist Cl - H + It effectively prevents the penetration of corrosive media; simultaneously, it does not react with oxygen at high temperatures because the gold plating does not react with oxygen, and the nickel plating, after annealing, has a denser structure, which can prevent the formation of an oxide film at high temperatures. Even without the protection of the gold plating, the nickel plating can maintain its stability at high temperatures, further ensuring overall oxidation resistance. In addition, it meets the performance requirements of the reaction chamber of CVD semiconductor manufacturing equipment in terms of conductivity, sealing, and infrared cleanliness.

[0082] Comparative Example 1 is set in Example 3. In the technical solution of Comparative Example 1, the pH value in S30 was 7.5 and the reaction temperature was 70°C; in S50, the pH value was 4.5 and the temperature was 55°C. The remaining steps and process parameters were the same as in Example 3. Parts with a coating were obtained. Their mechanical properties (coating adhesion and coating hardness), chemical properties (acid corrosion resistance and oxidation resistance), functional properties (conductivity and sealing surface smoothness), and cleanliness (surface particle count and metal impurity content) were measured, and the results are as follows: The coating adhesion decreased to level 3B, with issues including localized edge flaking and peeling within the grid area; simultaneously, the coating hardness decreased to below 200 HV; after neutral salt spray testing, the gold plating showed localized blackening, and the nickel plating exhibited white corrosion spots; acidic gas corrosion resulted in corrosion of the nickel plating, exposing copper in some areas; high-temperature oxidation caused localized oxidation of the nickel plating, leading to decreased adhesion; furthermore, the resistivity and contact resistance of the gold layer increased significantly, and the flatness of the sealing surface decreased significantly; the surface particle count increased to 25 particles / cm². 2 The above shows a significant increase in the total impurity content (≤8) and single impurity content (≤2).

[0083] The reason for this phenomenon is that during the preparation of parts including the coating in this invention, if the pH is alkaline, for example, 7.5, during electroless nickel plating, the OH groups in the plating solution... - A significant increase in concentration will react with Ni. 2+ The formation of Ni(OH)₂ precipitate, when mixed into the coating, creates a loose and porous structure, disrupting the continuity of the nickel plating. Simultaneously, high pH inhibits the decomposition of sodium hypophosphite, leading to insufficient reduction of nickel ions and weak interfacial bonding between the coating and the copper substrate. This results in a significant decrease in adhesion and increased porosity. Secondly, electroless nickel plating is temperature-dependent; if the temperature is lower than the set value, such as 70°C, it directly reduces the nickel plating thickness, failing to meet requirements and consequently decreasing both wear resistance and corrosion resistance. Furthermore, in the pulse electroplating gold coating step, if the plating solution is acidic, it will cause gold ions (Au) to... + The complex decomposes to produce highly toxic HCN gas, while releasing free Au. + Free Au + It readily forms precipitates with impurity ions in the plating bath. These precipitates, once mixed into the gold plating layer, introduce impurity defects, disrupting the continuous conductive structure of the gold plating layer and leading to a significant decrease in resistivity, contact resistance, and other properties. Furthermore, when the temperature is modified to exceed the set temperature, it can cause Au... + If the reduction rate is too fast, dendrite growth will occur, resulting in the formation of protruding fine dendrites on the surface of the gold plating. This will significantly reduce the performance of properties such as roughness and sealing surface flatness, making it impossible to meet the requirements. Moreover, high temperature will accelerate the dissolution of impurities in the plating solution, thus reducing the cleanliness of the plating.

[0084] As can be seen from the above analysis, in the technical solution of the present invention, the plating solution conditions for nickel plating or gold plating cannot be changed, and there is synergy between the various technical features. If any of the conditions is modified, the final part will not meet the requirements.

[0085] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing a part including a plating layer, characterized in that, The preparation method includes the following steps: Activation treatment is applied to copper-based parts; The activated copper substrate part is then subjected to nickel plating to obtain a copper substrate part including a nickel plating layer. The copper substrate part including the nickel plating layer is subjected to gold plating to obtain the part including the plating layer.

2. The preparation method according to claim 1, characterized in that, Prior to the activation treatment of the copper-based part, the preparation method further includes: The copper-based parts were pretreated sequentially with organic solvent, sodium hydroxide solution, and deionized water.

3. The preparation method according to claim 1, characterized in that, Before performing gold plating on the copper substrate part including the nickel plating layer, the preparation method further includes: Under an inert atmosphere, the copper substrate part including the nickel plating is annealed at 300℃~400℃ for 1h~2h, and then immersed in a solution containing 1%~3% sulfuric acid and 0.5%~1.0% hydrogen peroxide for 3min~5min at an immersion temperature of 25℃~35℃.

4. The preparation method according to claim 1, characterized in that, After obtaining the part including the coating, the preparation method further includes: The parts including the coating are placed in a drying device and dried at 100℃~150℃ for 1h~2h. Then, they are immersed in a passivation solution containing 0.5%~1.0% potassium dichromate and 3%~5% nitric acid for 2min~5min at a immersion temperature of 25℃~35℃.

5. The preparation method according to claim 1, characterized in that, The activation treatment of the copper-based parts includes: The copper-based part is immersed in a solution containing palladium salt and activator for 5 min to 10 min at a palladium salt concentration of 0.1 g / L to 0.5 g / L, an activator concentration of 5% to 10%, and a temperature of 30°C to 40°C.

6. The preparation method according to claim 1, characterized in that, The nickel plating solution used in the process comprises nickel sulfate 25 g / L ~ 35 g / L, sodium hypophosphite 20 g / L ~ 30 g / L, sodium citrate 10 g / L ~ 20 g / L, boric acid 5 g / L ~ 10 g / L, pH value 4.5 ~ 5.5, temperature 85℃ ~ 95℃, and nickel plating time 60 min ~ 90 min.

7. The preparation method according to claim 1, characterized in that, The plating solution used in the gold plating process comprises 3 g / L to 5 g / L potassium gold cyanide, 15 g / L to 25 g / L trisodium citrate, and 5 g / L to 10 g / L potassium dihydrogen phosphate. The pH value is 6.5 to 7.5, the temperature is 40°C to 50°C, and the pulse current density is 1 A / dm³. 2 ~3A / dm 2 The pulse width is 5ms~10ms, the pulse interval is 20ms~30ms, and the gold plating time is 30min~60min.

8. A part comprising a plating layer, characterized in that, The part including the coating is prepared by the preparation method according to any one of claims 1 to 7.

9. The part including the plating layer according to claim 8, characterized in that, In the parts that include plating, the thickness of the nickel plating is 5μm~8μm, and the thickness of the gold plating is 0.5μm~2μm.

10. An application of a part including a plating, characterized in that, The coated part of claim 8 or 9 is applied to the reaction chamber system of a CVD semiconductor manufacturing apparatus.

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