Method of Selecting the Operation Parameters of Electric Spindle with Aerostatic Supports for Separation of Semiconductor Plates to Crystals. Parts 2–3

Abstract

The article presents the results of studies of the shaft oscillation processes of a precision horizontal highspeed electric spindle with aerostatic radial and axial supports, used at Planar OJSC in equipment for separation of semiconductor plates into crystals. The studies were carried out using the developed mathematical models that take into account the design features of these electric spindles, including the cantilever mounting of the cutting tool, the imbalance of the diamond disc with the mandrel and the mass ratio of the main components of the electric spindle, as well as the results of their full-scale tests. Based on the analysis of the data obtained, regularities are shown that connect the amplitude values of the oscillations of the electric spindle shaft with the imbalance of the diamond disc with the mandrel and the rotational speed of the electric spindle, which made it possible to propose engineering dependences for choosing the permissible values of the imbalance and rational, from the standpoint of resonance conditions and permissible shaft oscillations, rotational speed of the electric spindle. Recommendations have been developed for the creation of a system for monitoring and active control of the parameters and functioning of the electric spindle in the process of separating semiconductor plates into crystals, which make it possible to use the resonant mode of radial oscillations to improve cutting conditions, excluding direct contact of the working surfaces of aerostatic supports, their seizure and loss of performance of the electric spindle. The article presents a method of selecting the operation parameters of a high-speed precision horizontal electric spindle with aerostatic radial and axial supports and a cantilever mounting of a diamond cutting disc. It is based on the analysis of the simulation results of shaft forced oscillations and data on the shaft oscillations during the operation of the electric spindle with different rotation frequencies and imbalances. The results obtained can be used to monitor shaft oscillations during the operation of the electric spindle, while the high operation efficiency of which is achieved by adaptive control of rotation frequencies taking into account the amplitudes of these oscillations.

Keywords

• aerostatic supports
• microelectronics
• forced vibrations
• cutting
• electric spindle
• adaptive control
• vibration
• monitoring