A removing process for multilayer nano thin-film structures on the hard disk surface

Abstract

In this investigation, the nanoscale removal of the multilayer metal film structure from the surface of glass hard disk platters is carried out by an electrochemical reaction. The electrolytic process used is assisted by the application of ultrasonic vibration at very high frequency which effectively enhances the speed and efficiency of metal layer removal. The results also show that higher concentrations of electrolyte and higher temperature also increase the rate of metal layer removal. A high electrolyte flow rate accompanied by high energy ultrasonics results in a high etching rate. The closer the anode is to the surface of the workpiece (platter) and the smaller the gap between the two electrodes, the higher is the etching rate. Further enhancement of etching rate can be achieved by using a smaller anode and cathode as well as by using electrodes with smaller edge radii. A high rotational speed of the anode and cathode module also enhances metal removal because it speeds up the flow of electrolyte across the surface of the workpiece to remove dregs and heat. A high current flow increases the rate of etching and allows a higher workpiece feed rate with a resultant increase in speed and overall efficiency. An optimal combination of processing parameters (electrical conditions, electrolyte flow and control, dregs removal, etc.) allows clean and complete removal of the multilayered nano metal film microstructure from the glass hard disk platters. The basic technology for the micro-electrochemical removal of the nano metal film from glass hard disk surfaces has been established. In addition, the results set a benchmark for the extension of basic laboratory equipment, as well as the implementation and commercial application of the method by industry.