硬盘知识-硬盘简介-hddharddiskdriveintroduction

HARD DISK DRIVE INTRODUCTION

硬盘大致分为，磁盘Media，读写头Read Write Head，马达Spindle Motor & V oice Coil Motor，底座Base，电路板PCBA等几大项，组合而成。

The Hard Disk Drive is made up of Media, Read Write Head, Spindle Motor, Voice Coil Motor, Base and PCBA.

Media的基板是金属或玻璃材质制成，为达到高密度高稳定的质量，基板要求表面光滑平整，不可有任何暇疵，然后再将磁粉Coating 溅渡到基板表面上，最后再涂上保护润滑层。此处有2项高科技，一为，如何制造出不含杂质极细微的磁粉二为，如何将磁粉均匀的Coating上去。

The Substrate of Media is made of metal or glass. To achieve the quality of high density and stability, the surface has to be very smooth without any defects. The magnetic coating is then layered on the substrate and after that the lubricant is covered on top. Two high-technologies procedure take place here: 1. To produce tiny particles of coating without impurities. 2. To coat the magnetic coating evenly.

以3.5＂Media计算，其内径为25mm，需扣掉最外及最内圈不保存Data的部分，

实际只剩20mm，如换算成60GB Media以Bit为单位(1个Bit记录0或1，8Bit

只可记录一个A，B，C…事实上不是以Bit为单位，在此为求简单易懂，固以

Bit形容)

Using a 3.5" Media to calculate, the inner diameter is 25mm. The actual

diameter becomes 20mm with the deduction of outer and inner circle that does not store data. If a 60GB Media is being converted into Bit as unit (A 0 or 1 accounts for 1 Bit, 1 character, such as A, B, C¡Ketc., accounts for 8 Bit. Bit is not the actual unit, but for the ease of comprehension, Bit is used.)

Media每面粗计密度为32,901,120,000 Bit，可见其密度相当高，所以Media不可有任

何污染，全程制造均需在Class 100高洁净度的Clean Room内，这也是硬盘机要求需在

Clean Room才能拆解的原因。

The density of each side of the Media is roughly 32,901,120,000 Bit, which is a very high density. So the Media can not be polluted anyhow. The whole manufacturing process of the Hard Disk must be in

a Class 100 highly purified Clean Room. This is also why the Hard Disk needs to be opened only in the Clean Room.

Media出厂时，是完全空白无任何讯号存在，需交由各硬盘厂组装时自行编码。

When the Media leaves the factory, it is blank and without any signals. It is encoded when the manufacturers of the Hard Disk is putting the Hard Disks together.

Head 是由上，下多片Read Write Head固定在同一组Arm上，来回移动时是整组Arm一

起移动，一般读写原理是，例如当10MB Data进来时，第1个Head先写4096 Byte(视

规格各异)，第2 Head写4096 Byte，依此类推，呈垂直读写，所以1 File是被分很多段

存在各磁面上，读取时也是同理，如此多磁头同时读写可达到高速要求，但现在又有更

先进的科技出现。

The Head is made up of Up Heads and Down Heads. Multiple read write heads are

fixed on the same set of Actuator Arm, so the whole set of the Arms move at the

same time. The writing principle of a Hard Disk is based on Vertical Recording, for example, when a data of 10MB is being stored, the first head writes 4096 Byte (Differs in specification), second head writes 4096 Byte and so on. A file is being broken up into many sections and stored into each Media. Reading a file in the Hard Disk also uses the same principle, which makes the heads to read together to achieve high speed. But there is more advanced technology nowadays.

Arm 因需高速来回移动，不可抖动，并精准移至原地址，各Head垂直度不可有分毫误差(限于头发的0.001 宽度)所以Head，Media均不可松动或偏角，否则会无法定轨。当前科技尚无法将误差的Head或Media调整回原址，因需以3D立体来看X，Y点及各Head的垂直点外，还需顾及外径与内径的公差，这也是硬盘怕碰撞的原因，更不可能去更换Head。

Because the Arm needs to move back and forth in high speed without jittering and move back to the original position precisely, the Head must be perpendicular without any deviation (limited to 0.001% of the diameter of a hair). The Head and the Media can not be loose or have skew angle, or else track following will be impossible. The technologies nowadays are not able to make the Head or the Media that has deviated back at their original position. Besides using a 3D graph to look at the X, Y coordinates and the perpendicular point of the Head, the difference of the outer and the inner diameter also have to be taken in consideration. This is why Hard Disks are fragile to collision and makes it impossible to change the Head.

Spindle Motor上装有1-多片Media，以7,200或10,000 RPM 定速旋转，为保持其

Balance不可抖动，所以其Bearing(分滚珠，液态)质量要求严谨，需能忍受24 H x 365

Days持续运转，而不磨损，不生成高温躁音。