Dynamic microwaviness measurements of super smooth disk media used in magnetic hard disk drives
Dynamic microwaviness measurements of super smooth disk media used in magnetic hard disk drives
复制标题
磁性硬盘驱动器中使用的超光滑磁盘介质的动态微波纹度测量
DOI：
10.1016/j.ymssp.2005.11.010
复制
发表时间：
2006
影响因子：
8.4
通讯作者：
A. Polycarpou
中科院分区：
文献类型：
--
作者：
Ki Myung Lee;A. Polycarpou
最近磁存储技术的进步表明，极高密度磁记录的可行性高达每平方英寸1太比特(1Tbit=1012比特)面密度。模拟表明，对于如此高的记录密度，需要大约3纳米(Nm)的物理头-盘间距。当记录滑块在高速旋转的磁盘上以如此低的间隔飞行时，它正在经历来自各种不同来源和宽频率范围的干扰。这些干扰可能会导致记录滑块大幅振动，这种情况称为飞行高度调制(FHM)，可能会导致数据丢失。一个重要的激励源来自旋转圆盘的表面不规则性，称为动态微波。术语动态微波度最近被引入，以区别于静态测量的常规地形特征。本文描述了对硬盘驱动器(HDD)系统中使用的磁盘介质进行可靠的动态微波度测量的过程。此外，这种测量是在不同的超光滑磁盘上进行的，这些磁盘旨在使用非接触式激光测振技术实现极高的记录密度。通过测量静态条件下圆盘的形貌特征以及与系统动力学的相互作用，研究了动态微波产生的根本原因。结果表明，动态微波特性主要是由58.8~250μm的地形特征引起的，其次是系统动力学效应。
Recent technological advances in magnetic storage suggest the feasibility of extremely high-density magnetic recording up to 1 terabit per square inch (1Tbit=1012bits) areal densities. Modelling indicates that approximately 3 nanometers (nm) of physical head-disk spacing is required for such high recording densities. When the recording slider is flying at such ultra low spacing over a high-speed rotating disk, it is experiencing disturbances from various different sources and of a wide frequency range. These disturbances may cause the recording slider to vibrate significantly, a condition that is known as fly height modulation (FHM), which may result in data loss. A significant source of excitation is from the surface irregularities of the rotating disk and is termed dynamic microwaviness. The term dynamic microwaviness has been introduced recently to differentiate from regular topographical features that are measured statically. In this paper, the procedure for making reliable dynamic microwaviness measurements of disk media used in hard disk drive (HDD) systems is described. Furthermore, such measurements are performed on different super smooth magnetic disks that are intended for extremely high recording densities using non-contact laser vibrometry. The root-cause of the dynamic microwaviness is investigated by measuring disk topographical features under static conditions and the interaction with system dynamics. It is found that dynamic microwaviness is primarily due to topographical features of spatial wavelengths ranging from 58.8 to 250μm, and secondarily due to system dynamic effects.