Study On The Surface Glazed Phenomenon Evaluation Method And Improvement Mechanism Of The Fixed Abrasive Lapping And Polishing Pad

Fixed abrasive chemical mechanical polishing technology is widely used in manufacturing sapphire substrates,chips and high-end integrated circuits due to its high efficiency,high abrasive utilization and environmental protection.However,the pad surface appears to be "glazed phenomenon" during the chemical mechanical polishing process using a fixed abrasive pad.This condition seriously affects the material removal ability of the fixed abrasive pad and the surface quality of the workpiece.In this paper,aiming at the problems of unclear glazed phenomenon mechanism and unknown evaluation method of existing fixed abrasive pad,the glazed phenomenon of fixed abrasive pad in service is studied from the angle of tribology.According to the experimental results,the glazed phenomenon of the fixed abrasive pad surface is quantitatively analyzed.The analysis results can provide reference for the using and dressing of fixed abrasive pad and improve its material removal ability and polishing quality during chemical mechanical abrasive polishing.To explore the improvement mechanism and influence rule of ethylenediamine additive on glazed phenomenon of fixed abrasive pad surface.The main research conclusions are as follows:(1)Evaluation Scheme of Glazed Phenomena on Fixed Abrasive Pad SurfaceThe surface roughness and hardness as well as the friction coefficient during the experiment are used to characterize the glazed phenomenon of the fixed abrasive pad surface.experiment.Preliminary comparative experiments showed that it was feasible to characterize the surface glazed phenomenon of the fixed abrasive pad by surface roughness,hardness and friction coefficient during the experiment.The reasons for glazed phenomenon on the surface of the fixed abrasive pad were concluded as follows: First,fixed abrasive pad surface micro-convex peaks and abrasives wear;Second,the pores were blocked by debris accumulation generated during the experiments.Third,after a long period of friction and extrusion,a smooth and hard layer was formed on the fixed abrasive pad surface.As a result,the friction coefficient decreases,the surface roughness decreases and the hardness increases of the fixed abrasive pad during the experiment.(2)Effect of Different Process Parameters on Glazed Phenomenon of Fixed Abrasive Pad SurfaceThe influence law of interface pressure and polishing slurry type on the surface glazed phenomenon of fixed abrasive pad was studied by single factor experiment.The experimental results showed that the surface roughness of fixed abrasive pad decreased and the hardness increased with the increase of interfacial pressure.According to the coefficient of friction,it was found that the time for stable glazed phenomenon of polishing pad decreased with increasing pressure.Under the conditions of oxalic acid and deionized water polishing slurries,the fixed abrasive pad surface was prone to glazed phenomenon.When triethanolamine was used as the polishing slurry,the interfacial pressure had a significant effect on the glazed phenomenon of fixed abrasive pad surface.The increase of pressure will lead to the aggravation of fixed abrasive pad surface wear to suppress the glazed phenomenon,but it will also cause the reduction of workpiece surface quality.(3)Mechanism and Effect of Ethylenediamine on Improving Glazed Phenomenon of Fixed Abrasive PadThe influence of ethylenediamine concentration on the improvement on surface glazed phenomenon of fixed abrasive pad and its mechanism of action under different interfacial pressures were studied by single factor experiments.On the basis of the analytical results,the findings were concluded as follows: Comparing with deionized water polishing slurry,adding ethylenediamine additive could improve the glazed phenomenon and prolong the single polishing life of fixed abrasive pad.The mechanism of ethylenediamine additive to improve the fixed abrasive pad surface glazed phenomenon is that ethylenediamine reacts with copper exposed in fixed abrasive pad,reducing its surface hardness.This reaction facilitates the wear removal of the swelling layer and the exposure of fresh abrasives,so that fixed abrasive pad can maintain the material removal ability for a long time.