As consumer electronics products become thinner and mor […]
As consumer electronics products become thinner and more versatile, the design of printed circuit boards has become more complicated, and the demand for high-density wiring and micro-hole circuit boards with high-density interconnect technology has increased significantly. However, HDI circuit boards are difficult to manufacture and costly, so copper oxide required for electroplating and filling is prepared. In addition to high purity and high activity to ensure copper ion concentration and dissolution rate in the plating solution, how to reduce copper oxide production costs have become one of the important technologies in the printed circuit board industry.
In general, a method for preparing high-activity copper oxide is disclosed in Chinese Patent No. 1335264A, in which a copper sulfate solution is placed in a reactor and air is introduced, and is oxidized at a low temperature of 80 to 85 ° C to form copper sulfate. The crystallization is followed by reaction with an aqueous solution of potassium hydroxide to form copper hydroxide and potassium sulfate, and finally subjected to pressure filtration washing, drying, pulverization, and the like to prepare a highly active copper oxide; in addition, U.S. Patent No. 6,649,131 discloses A method for preparing high-purity copper oxide from a waste acid etching solution, the main step of which is to react a 33 wt% aqueous sodium hydroxide solution with an acidic copper chloride etching waste liquid to form a copper hydroxide slurry at a temperature of 50 to KKTC. The copper hydroxide is dehydrated and converted into copper oxide, and then sintered at a high temperature to obtain high-purity acicular copper oxide; however, the copper hydroxide produced in the above process is a gel, which is washed several times to facilitate subsequent steps. This results in a large amount of wastewater discharge, and it is necessary to pay higher cost to treat the wastewater to reduce the environmental burden.