An online frequency measurement method for sc-cut quartz wafer grinding

Abstract

The invention discloses an online frequency measurement method for SC-cut quartz wafer grinding, which is characterized in that the online frequency measurement function includes an automatic search function and a tracking frequency measurement function; the automatic search function realizes the search for the current frequency of the SC wafer, and according to Different results of automatic search are processed differently; the tracking frequency measurement function includes dual frequency tracking function, single frequency tracking function, frequency measurement parameter initialization, frequency sweep parameter setting and switching function between the two functions; the invention provides a An online frequency measurement method for SC-cut quartz wafer grinding with high processing efficiency, high data accuracy, 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 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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