Polishing solution for electrochemical mechanical polishing of hard disk NiP

Abstract

The invention discloses polishing solution for electrochemical mechanical polishing of hard disk NiP. The polishing solution comprises the following components in percentage by mass: 1 to 10 percent of acid, 0.5 to 1 percent of potassium salt, 0.1 to 2 percent of complexing agent, 0.01 to 0.1 percent of surfactant, 1 to 5 percent of pH regulator KOH and the balance of water. The acid is one of citric acid or lactic acid or a mixture of the citric acid and the lactic acid; the potassium salt is potassium chloride or potassium nitrate; the complexing agent is ethylenediamine or aqueous ammonia or ethylene diamine tetraacetic acid (EDTA); and the surfactant is one of ammonium lauryl sulfate, ammonium dodecyl benzene sulfonate, TX-10, NP-5 and NP-9. The pH value of the polishing solution is regulated to be 5.0 to 6.0 by using the pH regulator KOH. The polishing solution does not contain abrasive particles, and can be used for polishing under low pressure (0.3 to 0.5psi); a polished NiP substrate has a few surface defects; and the polishing solution may replace the current chemical mechanical polishing technology for polishing the NiP substrate.

Description

Technical field: [0001] The invention relates to an electrochemical mechanical polishing solution in the manufacture of computer hard disks, in particular to a polishing solution for electrochemical mechanical polishing of hard disk NiP. Background technique: [0002] At present, the flying height of the computer head has been reduced to below 10nm, and there is a tendency to further reduce it. The magnetic head and the hard disk run so close (nanoscale gap) that the disk surface is required to be ultra-smooth (sub-nanometer roughness) and free from microscopic defects such as scratches and pits. If the surface of the hard disk has large waviness or there are micro-protrusions and micro-pits, it will damage the magnetic head or the magnetic medium on the surface of the disk during high-speed operation, or cause information readout failure. Therefore, before the magnetic medium of the disk is formed, the disk substrate must be polished to reduce the roughness of the substrat...

AI Technical Summary

Problems solved by technology

[0003] The use of electrochemical mechanical polishing to polish stainless steel and molds has been reported in domestic literature, but none of the polishing fluids in the literature can be used for electrochemical mechanical polishing of NiP in hard disk manufacturing, because the polishing of NiP has higher flatness requirements , and the polishing mechanism is different, requiring different polishing fluids