(1) for the pursuit of high quality products. In order to make the magnetic storage density is higher or the lens performance is better, the surface roughness must be lower. In order to make the electronic components of the normal function, requires not surface after processing residual metamorphic layer. According to the American Association of Microelectronics (SIA) requirement of the technology, the next generation of computer hard disk head requirements of surface roughness Ra is less than or equal to 0.2nm, H disk requirements of the surface scratch depth of less than LNM, surface roughness Ra is less than or equal to 0.1nmp. The processing precision of the 1983 TANIGUCHI of each period are summarized and the development trend was predicted on the basis of BYRNE, described the development of processing precision after 1940s.
(2) the product miniaturization pursuit. With the increase the machining accuracy is to reduce the size of engineering parts. From 1989 to 2001, decreased from 6.2kg to 1.8kg. Requirements for electronic circuit of high integrated silicon wafer to reduce surface roughness and improve the circuit for the exposure of movement precision manufacturing equipment, precision semiconductor lens. Small parts of the mean ratio of surface area and volume increasing, the surface quality of the workpiece and its integrity is more and more important.
(3) the product of the pursuit of high reliability. On the side of the load bearing while doing the relative movement of the parts, reduce the abrasion resistance of the surface roughness of the parts can be improved, improve the stability, prolong the service life. The use of high speed and high precision bearings Si3N4. The surface roughness of the ceramic ball is required to reach nanometer number. The chemical properties of metamorphic layer active, susceptible to corrosion, so to improve the corrosion resistance of the parts from the perspective of metamorphic layer processing requirements generated as small as possible.
(4) for the pursuit of high performance products. To improve the precision of motion of mechanisms, helps to reduce the mechanical properties of the fluctuation, reduce vibration and noise. The engine requires high mechanical sealing, good surface roughness can reduce leakage and reduce losses. After World War II, the aerospace industry part of work in the high temperature environment, which is made of titanium alloy, ceramics and other difficult materials for ultra precision machining and proposed the new task.