Contents 1. Introduction
A recent mobile phone is expanded explosive. The introduction of the optical fiber to the home (FTTH) is rapidly advanced at the same time. The importance of the quartz crystal resonator, the SAW device, and the optical device which is electromechanical functional component supports original and these of such a situation is recognized again. The material of these electromechanical functional components consists of various piezoelectric crystals including quartz crystal, and highly accurate cutting angle deviation of seconds or less is demanded of the quartz crystal wafer as for the cutting azimuth angle specification requested to the wafer which especially composes the device at the quartz crystal resonator for D-TCXO used for the most important of the mobile phone. Slicing crystal keeps the parallelism only to exclude the lapping process of the post-processing, demands the slicing thickness in the lot, and the uniform high precision processing is demanded. Ten years or more passed after the kerf loss of the unidirectional Multi-Wire-Saw slice by grinding with the free abrasive grain (material loss which occurred when the slicing was done) was fewer, and the difference of the thickness after the wafer had been sliced reported on the advantage that the warp became below the half by 1/10 or less though the rumbered quartz crystal had been sliced up to now for a long time by the Multi-Braid-Saw. As for the processing object of the Multi-Wire-Saw, the large diameter silicon is chiefly added to various improvements like slicing process and the direction etc. of running the other day. Multi-Wire-Saw has developed as a slicing technology that takes the place of the ID-Saw in the development competition with the ID-Saw which is the cutting method in internal dicer. On the other hand, markets such as mobile phones and digital equipment have expanded. Various piezoelectric crystal materials are used to achieve the device used for these various equipments. The content of the specification of these wafers is made more efficient. Even if it differs from the large diameter silicon when the Multi-Wire-Saw is applied to slicing the piezoelectric crystal and is maximum five inches diameters only have to be able to be slice. However, the highest one is demanded of the processing accuracy. Moreover, because the inspection of the finish wafer thickness accuracy is possible the check on PPM level by the means of frequency, the processing finish wafer accuracy control by the manufacturing process is comparatively easy. It is important that peculiar physical properties to the oxide crystal are known well to apply the multi-wire-saw to various piezoelectric crystals on the other hand. As for the wafer sliced by the Multi-Wire-Saw, it is hoped that there is basically no warp of the wafer that parallelism (TTV: Total Thickness Variation) accuracy influences zero and the end product as much as possible as well as silicon. In a highly accurate machine tool, it is evidence to bring high-value-added for a long term. In this paper, various slicing conditions to achieve a highly accurate processing are examined, and the unidirectional multi-wire-saw is the most suitable for the achievement.
