硬盘巨磁电阻磁头的超精密抛光工艺

硬盘巨磁电阻磁头的抛光可分为自由磨粒抛光和纳米研磨,在自由磨粒抛光中,精确控制载荷和金刚石磨粒的粒径,可以避免脆性去除实现延性去除。通过控制抛光过程中的抛光盘表面粗糙度、金刚石粒径大小及粒径分布和载荷等进行滚动磨粒和滑动磨粒比例的调控,获得较好的磁头表面质量和较高的材料去除率。在自由磨粒抛光阶段,先采用铅磨盘抛光,然后用锡磨盘抛光,以纳米研磨作为最后一道抛光工序对磁头表面进行研磨,获得了亚纳米级粗糙度的磁头表面。用两种工艺制作的纳米研磨盘进行加工,分别获得了0.37nm和0.8nm的磁头表面粗糙度,去除率分别为5.3 nm/min和3.9nm/min。

Ultra Precision Machining Technique of GMR Rigid Disk Head Sliders

Giant magnetic resistance(GMR)magnetic head polishing process can be classified as lapping and nano-grinding.The material can be removed in ductile way by controlling load and size of diamond in lapping.Different material removal mechanism can be produced by rolling grains and sliding grains.The ratio of rolling and sliding grains was adjusted in an appropriate way by controlling the pad roughness,diamond size,diamond size distribution and load to achieve an excellent magnetic head surface and high removal rate.In abrasive free lapping process,a lead plate was used at first,and then,a tin plate was used as a lapping plate.Sub nanometer roughness of sliders' surface was achieved by using nano-grinding as the final machining process.The fabrication of nano-grinding pad is the main factor that influences the surface quality. Two tin plates were used as nano-grinding plate and diamond abrasive was embedded in them in different ways.In this way,the roughness Rq of the sliders' surface is measured at an arrange of 0.37nm to 0.8nm,while the removal rate is measured at an arrange of 5.3nm/min to 3.9nm/min.