On-line grinding frequency measurement method of sc-cut quartz wafer

Abstract

The invention discloses an online grinding frequency measurement system, which includes a frequency measurement test function and an online frequency measurement function; the frequency measurement test function includes a single frequency sweep double resonance frequency waveform matching function, a single frequency sweep resonance frequency data processing function, a unit Time data processing function; online frequency measurement function includes automatic search function and tracking frequency measurement function; the present invention provides an online grinding frequency measurement system with high processing efficiency, high processing precision, and accurate distinction of dual-mode frequencies.

Description

technical field [0001] The invention relates to the field of quartz wafers, more specifically, it relates to an SC-cut quartz wafer on-line grinding frequency measurement method. Background technique [0002] The core components of crystal oscillators (active crystal oscillator, oscillator) and crystal resonators (passive crystal oscillator, crystal) are quartz wafers. The design of quartz wafers largely determines the performance of oscillators and resonators. The material of the quartz wafer is a quartz rod (quartz). Due to the anisotropy of the crystal, the quartz wafer cut from different directions of the quartz rod has completely different effects. The cutting method of the quartz rod determines the elasticity of the quartz wafer. Constant, dielectric constant, expansion coefficient, temperature characteristics, etc., such as frequency temperature coefficient, frequency thickness coefficient, stress compensation coefficient, etc. The difference in these characteristics ...

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Problems solved by technology

[0018] 1. The resonant frequency obtained through the automatic frequency search cannot be confirmed as the resonant frequency of B mode or C mode, but what we need is the C mode frequency. If the measurement and control instrument performs tracking frequency measurement and control according to B mode, then grinding can be obtained The final frequency is wrong and the B-mode frequency has been overclocked, which will cause the entire plate to be scrapped

[0019] 2. Even if the current measurement and control instrument detects the correct C-mode frequency and stably tracks and shuts down, but we cannot get the B-mode frequency, the user still cannot confirm whether the final frequency obtained by grinding is correct. It is necessary to take the quartz wafer out of the grinder Confirmation can only be confirmed after measurement on standard instruments such as network analyzers, resulting in extremely low efficiency

[0020] 3. During the automatic frequency search process of the currently used frequency measuring instrument, since only one frequency value is searched, it is impossible to confirm whether it is a B-mode frequency or a C-mode frequency.

[0021] At the same time, the current SC-cut quartz wafer needs to confirm the frequency after grinding. The frequency confirmation of the B-mode and C-mode can only be performed through a network analyzer or other frequency measurement devices, and the frequency cannot be confirmed when it is in the grinding machine, resulting in The efficiency is extremely low, and it is easy to break the wafer and cause losses when taking materials back and forth

[0022] Based on the above reasons, the current grinding process of SC-cut quartz wafers is basically based on the number of turns to judge the thickness and stop the control, and then use the network analyzer or other frequency measurement devices to confirm the frequency. This method will cause the stop frequency to be extremely high Stable, low repeatability, and there is a possibility of frequency judgment error

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