Nickel plating method after metallization of alumina ceramics includes acid leaching, pickling, nickel plating and post-treatment, characterized in that the acid leaching is to immerse the metallized alumina ceramics into hydrofluoride with a mass concentration of not less than 15% 5-10 seconds in the acid solution, wipe out the alumina ceramic with a cotton cloth dipped in hydrofluoric acid solution, and then rinse with water for not less than 10 seconds to obtain the first-treated alumina ceramic; A hydrochloric acid solution with a concentration of not less than 20% is subjected to an acid wash of the first-treated alumina ceramics for 0.5 to 1 minute, and then washed with water for not less than 10 seconds to obtain the second-processed alumina ceramics; the nickel plating Nickel is used as the anode, and the second-processed alumina ceramic is used as the cathode. Nickel is plated for 20-25 minutes at a current density of 0.5-1. OA/dm2 and an electrolyte temperature of 18-40°C. The electrolyte is a mixed aqueous solution of nickel chloride and HCl, the concentration of nickel chloride in the electrolyte is 180-220g/L, and the concentration of HCl is 160_200g/L; the post-treatment is to perform nickel-plated alumina ceramics sequentially It can be washed with water, dehydrated with acetone, dehydrated and dried. The concentration of nickel chloride in the electrolyte is preferably 200 g/L, and the concentration of HCl is preferably 180 g/L. Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The nickel plating method of the present invention specifies the operation process and parameters of each step in detail, which can provide accurate guidance to the majority of operators and process designers to ensure operation The process can achieve the desired effect and can be reproduced steadily. 2. In the traditional process design, less consideration is given to the cleaning before nickel plating. Ultrasonic cleaning and degreasing are usually used, which cannot remove the small particles and impurities that are not firmly adhered during the metallization process, resulting in poor quality of nickel plating. Stable. The treatment provided by the present invention before metallizing the alumina ceramic after nickel plating can significantly improve the quality of nickel plating. 3. The current density, electrolyte temperature and holding time of nickel plating described in the present invention are obtained through many tests and practices. This parameter is generally not available as a technical secret. This parameter is published in the present invention. Using this nickel plating condition, a nickel layer of 8-12 microns tightly bonded to the metallization layer can be obtained. This thickness of the nickel layer is more suitable for brazing.
The method of nickel plating after metallization of alumina ceramics is as follows: 1. Preparation: Add 15% hydrofluoric acid solution, 20% hydrochloric acid solution and acetone to separate containers, the amount of addition should be at least The metallized alumina ceramics were completely submerged respectively. 2. Pickle to fix the metallized alumina ceramics with nickel wire, nickel clips or other hangers, you need to bring a finger sleeve during installation, and then immerse the metallized alumina ceramics in the hydrofluoric acid solution of step 1 5-10 seconds, because acid leaching can not fully guarantee the cleanliness of the metallized layer, so after taking out, wipe the alumina ceramic with cotton cloth dipped in hydrofluoric acid solution, and then rinse with running tap water for 15 seconds to get the first treatment Alumina ceramics; 3. Pickling The hydrochloric acid solution of step 1 is used for the first treatment of the alumina ceramics for 0.5 to 1 minute pickling, and then rinsed with flowing water for 15 seconds to obtain the second treatment of oxidation Aluminum ceramics; 4. Nickel plating uses nickel as the anode and the second-treated alumina ceramics as the cathode, under the conditions of current density 0. 5-1. OA/dm2, electrolyte temperature 18-40 °C nickel plating 20-25 minutes, where the electrolyte is a mixed aqueous solution of nickel chloride and HCl, the concentration of nickel chloride in the mixed aqueous solution is 200g/L, and the concentration of HCl is 180g/L; 5. Post-treatment will be nickel-plated alumina Remove the ceramic from the nickel plating tank and wash it with running tap water for 60 seconds; then use acetone to deoil and dehydrate the nickel-plated alumina ceramic for no less than 3 seconds; then blow dry the nickel plating with compressed air The moisture on the surface of the alumina ceramics is finally placed in a drying oven and dried at 80-100°C for 20min. After wearing nylon gloves or finger cots, take them out and put them in the packaging or wrap them with lint-free paper. It is reserved when the process is sealed with metal. The inventor used the method of the present invention to perform batch traveling wave tube ceramic metal sealing, and achieved good results. (1) In batch metal ceramic sealing, the welding failure rate (ie, welding leakage) was 2%, and the existing The failure rate in technology is 5% to 10%. (2) In the finished multi-injection traveling wave tube sealed in bulk cermet, the storage life of the tube can be guaranteed to be 5-7 years, while the storage life of the same type of tube abroad is 3-5 years.
A nickel plating method for alumina ceramic after metallization, including acid leaching, pickling, nickel plating and post-treatment, characterized in that the acid leaching is to immerse the metallized alumina ceramic into a mass concentration of not less than 15% 5-10 seconds in hydrofluoric acid solution, wipe out the aluminum oxide ceramic with a cotton cloth dipped in hydrofluoric acid solution, and then rinse with water for not less than 10 seconds to obtain the first treated aluminum oxide ceramic; the acid cleaning is The first-treated alumina ceramics were pickled for 0.5 to 1 minute with a hydrochloric acid solution with a mass concentration of not less than 20%, and then washed with water for not less than 10 seconds to obtain the second-processed alumina ceramics; Nickel plating is based on nickel as the anode, with alumina ceramics treated for the second time as the cathode, under the conditions of current density 0. 5-1. OA/dm2, electrolyte temperature 18-40°C, nickel plating for 20-25 minutes , Where the electrolyte is a mixed aqueous solution of nickel chloride and HCl, the concentration of nickel chloride in the electrolyte is 180-220g/L, and the concentration of HCl is 160_200g/L; the post-treatment is to use nickel-plated alumina ceramics It can be sequentially washed with water, acetone deoiled, dehydrated and dried. First, pickling to remove the fine particles and other impurities that are not firmly adhered on the ceramic surface during the metallization process, and then pickling to remove the damaged layer on the surface of the metallization layer after acid leaching, exposing the fresh metallization surface Then, after nickel plating and post-treatment, nickel-plated alumina ceramic is obtained, which is reserved for the next process when sealing with metal. The method of the invention can remove the fine particles and impurities that are not firmly adhered during the metallization process, and significantly improve the quality of nickel plating; the current density, electrolyte temperature and holding time of the nickel plating of the invention are multiple times Obtained during the test and practice, a nickel layer of 8-12 microns tightly bonded to the metallization layer can be obtained. This thickness of the nickel layer is more suitable for brazing and welding.