A Research And Design Of Crystal Resonator Resonant Frequency Regulation System Based On Laser Marking

Our country is absolutely a main crystal resonator out-sourcing country around the world,most of the companies are world wide suppliers.Small-scale companies make tens of millions resonators each year,while large-scale ones make hundreds of millions.Right now the problems constraining the manufacture capability include: low capability of self-research and development on high performance measuring devices used through all stages during manufacture,not all devices needed are developable.Meanwhile mechanical manufacture research is not well motivated and far from practice.So whether the enhancement of self research capability or capability of mechanical manufacture do have breakout will definitely lower down the cost.Laser marking technology has been well developed over years and been the main way of marking on object surface made by all kinds of material.Nd:YAG laser generator is a member of the big family that generate infrared light with 1.06um wavelength.It is specilized at marking on metal with high energy density and low heating rate.During the manufacture process the resonator will be plated with argentum.According to the crystal physics the resonant frequency of crystal resonator will change when the argentum cover is partly removed. So it is possible to regulate the resonant frequency of crystal resonator by burning out part of the argentum plate with laser beam.This thesis do some research and design on laser-marking based crystal resonator frequency regulation system which achieves the goal of mechanical manufacture by burning out part of the argentum cover via laser beam.During the design process of the whole electrical system the main research work includes:(1)Do some integration of former discrete devices used in manual manufacture shrinking the volume and making the whole electrical system more integral using the enhanced function 51-core MCU C8051F310 provided by CYGNAL.Two low supply voltage and high accuracy oscillator scenarios based on wide band op-amp AD380 is disscussed for the issue that voltage supply of modules is different affecting the integration.And simulation in Multisim is carried out to verify the performance.(2)Make some change of the standard digital frequency measurement method by first frequency-dividing the test signal then sampling it with high frequency pulses.This way could improve the accuracy of standard method greatly.(3)In order to resolve the location error caused by resonator mechanical location system a laser locating and rectification of marking coordinates of resonators deviated from original coordinates method is disscussed.First laser scan the possible location of the top comer of the resonator to locate it,then calculate the coordinates of the whole resonator according the geometry relationship between them.This method could rectify the horizontal error and inclination independently.MATLAB simulations are carried out to demonstrate the trace of the top comer of resonator during inclination and the 12 points rectification coordinates of a randomly chosen inclination state is calculated and showed too.Simulations based on more complicated conditions in which horizontal errors is taken into accounted are also carried and some elemental solutions are dissussed after that.