On-line single-frequency tracking frequency measurement method of SC cut quartz wafer on-line grinding frequency measurement system

Abstract

The invention discloses an on-line single-frequency tracking frequency measurement method of an SC cut type quartz wafer on-line grinding frequency measurement system. A frequency sweep range of single-frequency tracking should cover a low-frequency frequency sweep range in which the current frequency is regarded as a high-frequency frequency, and a high-frequency resonance frequency sweep range in which the current frequency is regarded as a low-frequency frequency, and the current frequency serves as the basis of single-frequency tracking and the judgment basis of the other frequency in theSC wafer double-resonant frequency. In the single frequency sweeping and measuring process, it must be guaranteed that the current frequency is measured firstly, if the current frequency is not measured, frequency judgment of the other two frequency sweeping ranges is not conducted, and if the current frequency is measured, judgment of a forward frequency waveform and a backward frequency waveformis conducted. The invention provides the online single-frequency tracking frequency measurement method of the SC cut type quartz wafer online grinding frequency measurement system, and the method hasthe advantages of high processing efficiency, high data precision and accurate dual-mode frequency distinguishment.

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 system. 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

[0007] 1. The resonant frequency obtained by automatic frequency search cannot be confirmed as the resonant frequency of B-mode or C-mode

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

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.

At the same time, the current SC-cut quartz wafer needs to be frequency confirmed after grinding, and the frequency confirmation of B-mode and C-mode can only be performed through a network analyzer or other frequency measurement devices, but cannot be confirmed when it is in the grinding machine

[0008] 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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