GMR硬盘磁头自由磨粒抛光材料去除机理研究

Mechanism of Material Removal in Free Abrasive Polishing of GMR Hard Disk Sliders

同时获得高去除率和超光滑平整的表面是硬盘磁头自由磨粒抛光的矛盾,研究自由磨粒抛光材料去除规律可以优化抛光工艺。采用修正环型浮动块抛光机抛光GMR硬盘磁头,采用场发射扫描电镜和原子力显微镜观察磁头表面形貌。通过改变抛光盘的表面形貌、抛光液以及抛光压力等抛光条件,获得不同的磁头表面形貌,磁头表面有磨粒产生的划痕和少量微坑,显示材料主要以微切削方式去除。划痕和微坑的深浅、数量随抛光条件的不同而改变。进一步采用纳米压痕仪测量磁头表面材料去除率,并研究抛光盘、抛光压力和抛光液等参数与材料去除率的关系,建立了GMR磁头材料去除率模型,并可预测表面粗糙度,与实验结果基本相吻合。据此可以优化工艺,在获得最佳表面质量的同时,获得高的去除率,兼顾效率与品质的因素。

It is a contradiction to achieve a high material removal rate and a super smooth surface in lapping of magnetic head. Study on material removal is helpful to improve the lapping process. The float-piece polisher armed with conditioning ring was used in GMR hard disk sliders＇ lapping. Electroluminescent SEM and AFM were used to measure the sliders＇ surface. The topography of sliders was different when the work conditions such as topography of pad, slurry and lapping pressure changed. There are Nicks and a few micro-indentations were observed, it indicated that the surface material was removed in micro-cut mainly by abrasive. The number and the depth of the nicks and micro-indentations on the sliders＇surface varied with the lapping condition, and an ideal sliders surface could be achieved in an appropriated lapping condition. Armed with nano-indentation hardness, advanced research was carried out to investigate the effect of pad, slurry and lapping pressure on the material removal rate. A material removal rate model was developed and used to estimate the surface roughness. The model is consistent with experiments. According to the model, the lapping techniques can be optimized to obtain excellent slider surface and high efficiency simultaneously.