CN102914698A - Circuit and method for measuring resistance loss of crystal oscillating wafer of crystal control instrument - Google Patents
Circuit and method for measuring resistance loss of crystal oscillating wafer of crystal control instrument Download PDFInfo
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- CN102914698A CN102914698A CN2012104254455A CN201210425445A CN102914698A CN 102914698 A CN102914698 A CN 102914698A CN 2012104254455 A CN2012104254455 A CN 2012104254455A CN 201210425445 A CN201210425445 A CN 201210425445A CN 102914698 A CN102914698 A CN 102914698A
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Abstract
The invention provides a circuit and a method for measuring the resistance loss of a crystal oscillating wafer of a crystal control instrument and relates to the technical field of crystal control instruments. The invention solves the technical problem about measurement on the resistance loss of the crystal oscillating wafer. In the circuit, a microprocessor controls a sinusoidal signal generator to output a sine wave test signal to the crystal oscillating wafer to be measured; the oscillating amplitude of the crystal oscillating wafer to be measured under the sine wave test signals of different frequency is measured by the microprocessor and normalized; and the resistance loss of the crystal oscillating wafer is calculated. The circuit and the method provided by the invention can be used for checking the loop status of a crystal oscillating probe of the crystal control instrument, the mounting quality of the crystal oscillating wafer, the exchange time of the crystal oscillating wafer and the like.
Description
Technical field
The present invention relates to brilliant control instrument technology, particularly relate to a kind of crystal-vibration-chip resistance loss metering circuit of brilliant control instrument and the technology of measuring method thereof.
Background technology
Brilliant control film-thickness monitoring is to utilize the resonance frequency of quartz wafer and the vacuum coating process controller that the relation between the thicknesses of layers is come the controlling diaphragm layer thickness, mainly by the crystal oscillator probe with quartz wafer, and for the crystal oscillator frequency metering circuit of measuring the quartz wafer resonance frequency, the film speed control the electric circuit constitute processed that is used for control plated film speed, in the crystal oscillator frequency metering circuit, be provided with oscillator, the crystal oscillator probe is installed in the vacuum chamber of vacuum coating equipment, and a side surface of the quartz wafer on the crystal oscillator probe is exposed to the top of evaporation source.
Sample strip is being carried out in the vacuum coating process, coating materials can be deposited on quartz wafer and the sample strip, the resonance frequency of quartz wafer can reduce along with the coating materials deposition, the resonance frequency that brilliant control film-thickness monitoring utilizes the crystal oscillator frequency metering circuit to measure quartz wafer changes, transformational relation according to resonance frequency and thicknesses of layers, draw depositional coating thickness, and depositional coating is at difference thickness difference constantly, can obtain the coating materials rate of sedimentation, and then the power by pid algorithm control evaporation source, to obtain the stable rate of sedimentation that is tending towards design speed.Because quartz crystal slice is in a band frequency variation range, be varied to linear relationship with thicknesses of layers, so that brilliant control film-thickness monitoring is with respect to other film thickness monitoring methods (for example optics control method), the be more convenient for rate of sedimentation control of quartz wafer plated film, therefore brilliant control film-thickness monitoring has become one of standard control instrument of vacuum coating equipment gradually.
For crystalline substance control instrument, crystal-vibration-chip frequency and variation thereof are the foundations that thickness calculates, and frequency measurement is the core of all brilliant control instrument.At present the raw data that provides of conventional brilliant control instrument also only limits to oscillation frequency, does not provide for other parameters of crystal-vibration-chip.The crystal-vibration-chip that brilliant control instrument uses is generally the AT cutting mode, and good frequency-temperature characteristic is arranged near normal temperature, and its acoustic oscillations is thickness shearing mode.In the vacuum coating process, in order to guarantee the temperature stabilization of crystal-vibration-chip, the probe position need to lead to chilled water.
In the vacuum coating control procedure, because the crystal-vibration-chip temperature is lower, especially do not have the thermal evaporation film forming procedure of the auxiliary or low rate of ion gun, so the rete roughness of crystal-vibration-chip surface deposition is larger, short texture, stress is large.When the inner acoustics shear oscillation of crystal-vibration-chip ripple propagates into the loose of crystal-vibration-chip surface or the crackle rete is arranged, have larger oscillation energy loss, can cause crystal-vibration-chip Q value to reduce, it is large that electrical equivalent resistance becomes.This loss is larger, and the resonance frequency stability of crystal-vibration-chip is just lower, even no longer vibration; The unstable reaction of the resonance frequency of crystal-vibration-chip is being that speed is unstable to the consequence in the coating materials rate of sedimentation control of vacuum coating, and the crystal-vibration-chip nonoscillatory then can cause the coating materials rate of sedimentation control of vacuum coating was lost efficacy.This because the crystal-vibration-chip own loss becomes bring greatly unstable, so that brilliant control instrument is difficult to proceed authentic and valid speed control.In addition, when this speed wild effect occurs, the thickness record on the brilliant control instrument also will be difficult to accurately.This should be avoided in the application of crystalline substance control instrument as far as possible.
In the vacuum coating film forming procedure, the reason that brilliant control speed shakiness occurs is more, and it only is that one of them is the most fatal also that the crystal-vibration-chip own loss becomes greatly, because in this case, brilliant control instrument thickness record also is inaccurate, and does not have repeatability.The situations such as crystal oscillator probe processing is bad, electrode fouling, installation are bad, cable failure, bad, the new crystal-vibration-chip of crystal-vibration-chip surface are polluted also can not get effecting reaction only having on the crystalline substance control instrument of frequency measurement, also do not measure the effective ways of crystal-vibration-chip loss at present.
Summary of the invention
For the defective that exists in the above-mentioned prior art, technical matters to be solved by this invention provides a kind ofly can measure the crystal-vibration-chip resistance loss, crystal-vibration-chip resistance loss metering circuit and the measuring method thereof of the crystalline substance control instrument that the coating materials rate of sedimentation control wild effect of avoiding causing greatly because of the crystal-vibration-chip loss occurs.
In order to solve the problems of the technologies described above, the crystal-vibration-chip resistance loss metering circuit of a kind of brilliant control instrument provided by the present invention, relate to crystal-vibration-chip to be measured, it is characterized in that: this circuit comprises microprocessor, sinusoidal signal generator, and two voltage follow loops, described two voltage follow loops are respectively the first voltage follow loop, second voltage is followed the loop;
Described microprocessor is provided with a control signal output terminal, a measuring-signal input end, and the microprocessor-based control signal output part is received the control signal input end of sinusoidal signal generator;
The input end in described the first voltage follow loop is received the signal output part of sinusoidal signal generator, and the output terminal in the first voltage follow loop is received the input end that second voltage is followed the loop through a divider resistance;
The output terminal that described second voltage is followed the loop is received the measuring-signal input end of microprocessor successively through a commutating circuit, a filter circuit, a level translation loop, an analog to digital converter;
An electrical connection terminal ground connection of described crystal-vibration-chip to be measured, another electrical connection terminates to the input end that second voltage is followed the loop.
What further, described commutating circuit adopted is the full-wave rectification loop.
What further, described filter circuit adopted is the low-pass filtering loop.
The measuring method of the crystal-vibration-chip resistance loss metering circuit of brilliant control instrument provided by the present invention is characterized in that:
The crystal-vibration-chip to be measured of crystalline substance being controlled instrument separates with the circuit of crystalline substance control instrument, and the nominal resonant frequency value with crystal-vibration-chip to be measured is set as the sweep frequency higher limit again, the sweep frequency higher limit is deducted 1 megahertz after resulting value be set as the sweep frequency lower limit;
Utilize microprocessor to export control signal to sinusoidal signal generator, make sinusoidal signal generator to crystal-vibration-chip sine wave output test signal to be measured, measure the oscillation amplitude of crystal-vibration-chip to be measured under the sinusoidal wave test signal of different frequency by microprocessor, and this is carried out normalized;
The concrete steps of normalized are as follows:
1) measures the oscillation amplitude of crystal-vibration-chip to be measured when the frequency of sinusoidal wave test signal is the sweep frequency higher limit, as the full range value of upper limiting frequency benchmark, measure the oscillation amplitude of crystal-vibration-chip to be measured when the frequency of sinusoidal wave test signal is the sweep frequency lower limit, as the full range value of lower frequency limit benchmark;
2) calculate coefficient slope and the intercept of linear relationship between frequency and the full amplitude, specific formula for calculation is:
D1=?k×f1+b
D2=?k×f2+b
Draw:
k?=?（D2-D1）/（f2-f1）
b?=?（f2×D1-f1×D2）/（f2-f1）
Wherein, D1 is the full range value of upper limiting frequency benchmark, and D2 is the full range value of lower frequency limit benchmark, and f1 is the sweep frequency higher limit, and f2 is the sweep frequency lower limit, and k is the coefficient slope, and b is intercept;
3) set the test frequency value, utilize the microprocessor control sinusoidal signal generator output frequency value sinusoidal wave test signal consistent with the test frequency value;
4) utilize microprocessor to measure crystal-vibration-chip to be measured oscillation amplitude when the test frequency value, and according to surveying the oscillation amplitude value, calculating the resistance loss of crystal-vibration-chip to be measured when the test frequency value be:
Z?=?DS/D×100%
D=?k×f+b
Wherein, Z is resistance loss, and DS is actual measurement oscillation amplitude value, and f is the test frequency value.
Crystal-vibration-chip resistance loss metering circuit and the measuring method thereof of brilliant control instrument provided by the invention, by crystal-vibration-chip being applied the sinusoidal wave test signal of different frequency, measure the oscillation amplitude of crystal-vibration-chip under the sinusoidal wave test signal of different frequency, and this is carried out normalized, thereby measure the crystal-vibration-chip resistance loss, the coating materials rate of sedimentation control wild effect of avoiding causing greatly because of the crystal-vibration-chip loss occurs, can be used for checking the crystal oscillator probe circuit state of brilliant control instrument, and the installation quality of crystal-vibration-chip, replacing opportunity of crystal-vibration-chip etc.
Description of drawings
Fig. 1 is the theory diagram of crystal-vibration-chip resistance loss metering circuit of the crystalline substance control instrument of the embodiment of the invention;
Fig. 2 is the circuit diagram of crystal-vibration-chip resistance loss metering circuit of the crystalline substance control instrument of the embodiment of the invention;
Fig. 3 is the crystal-vibration-chip resistance loss metering circuit of the crystalline substance control instrument of the embodiment of the invention, is the quantitative calculating chart of reactance of the crystal-vibration-chip of 5.9995MHz to nominal resonant frequency.
Embodiment
Below in conjunction with description of drawings embodiments of the invention are described in further detail, but the present embodiment is not limited to the present invention, every employing analog structure of the present invention and similar variation thereof all should be listed protection scope of the present invention in.
As shown in Figure 1, the crystal-vibration-chip resistance loss metering circuit of a kind of brilliant control instrument that the embodiment of the invention provides, relate to crystal-vibration-chip X1 to be measured, it is characterized in that: this circuit comprises microprocessor U3, sinusoidal signal generator S1, and two voltage follow loops, described two voltage follow loops are respectively the first voltage follow loop U11, second voltage is followed loop U12;
Described microprocessor U3 is provided with a control signal output terminal, a measuring-signal input end, and the control signal output terminal of microprocessor U3 is received the control signal input end of sinusoidal signal generator S1;
The input end of described the first voltage follow loop U11 is received the signal output part of sinusoidal signal generator S1, and the output terminal of the first voltage follow loop U11 is received the input end that second voltage is followed loop U12 through a divider resistance R6;
The output terminal that described second voltage is followed loop U12 is received the measuring-signal input end of microprocessor U3 successively through a commutating circuit U13, a filter circuit U14, a level translation loop U15, an analog to digital converter U2;
The electrical connection terminal ground connection of described crystal-vibration-chip X1 to be measured, another electrical connection terminates to the input end that second voltage is followed loop U12.
In the embodiment of the invention, described voltage follow loop, commutating circuit, filter circuit, level translation loop are prior art;
Fig. 2 is that the measurement resonance frequency is the physical circuit of the crystal-vibration-chip resistance loss of 5.9995MHz, in this circuit:
The voltage follow loop is made of single operational amplifier, and wherein the first voltage follow loop is made of single operational amplifier U1C, and second voltage is followed the loop and is made of single operational amplifier U1D;
What commutating circuit adopted is by two operational amplifier U1A, U1B, two diode D1, D2, and six full-wave rectification loops that resistance R 1, R2, R31, R32, R4 consist of, wherein the resistance of R1, R2, R31, R32, R4 is 500 Ω, the resistance of R5 is 1k Ω;
The level conversion loop is made of a gain resistor R5;
Filter circuit is the RC low-pass filtering loop that is made of a resistance R 7, a capacitor C 1;
The input end of analog to digital converter U2 is provided with two protection diode D3, D4, and the full scale of analog to digital converter U2 is 3.3V;
The normal phase input end of operational amplifier U1C connects the signal output part of sinusoidal signal generator S1, and the output terminal of operational amplifier U1C is received the normal phase input end of operational amplifier U1D through divider resistance R6;
The electrical connection terminal ground connection of crystal-vibration-chip X1 to be measured, another electrical connection terminates to the normal phase input end of operational amplifier U1D;
Vo among Fig. 2, Vi, Vx are the voltage of three voltage data points in the circuit, and the voltage of these three voltage data points has following relation:
Vo?=?-Vi×R5/R4?-?Vx×R5/R3；
Vi〉0 o'clock, the D1 cut-off, the D2 conducting, this moment Vx=-(R2/R1) Vi=-Vi, then Vo=Vi * R5/R4;
Vi＜0 o'clock, the D1 conducting, the D2 cut-off, this moment Vx=0, then Vo=-Vi * R5/R4;
The Vo value is the output gain in level conversion loop;
The purpose in level conversion loop is so that the input terminal voltage maximal value of analog to digital converter U2 is no more than power supply voltage, for taking full advantage of the resolving power of analog to digital converter U2, it is many that the input terminal voltage maximal value of analog to digital converter U2 should be adjusted at half of supply voltage.
Among other embodiment of the present invention, described voltage follow loop, commutating circuit, filter circuit, level translation loop also can adopt other the existing loop that can realize identical function to substitute.
The measuring method of the crystal-vibration-chip resistance loss metering circuit of the crystalline substance control instrument that the embodiment of the invention provides is characterized in that:
The crystal-vibration-chip to be measured of crystalline substance being controlled instrument separates with the circuit of crystalline substance control instrument, nominal resonant frequency value with crystal-vibration-chip to be measured is set as the sweep frequency higher limit again, resulting value was set as the sweep frequency lower limit after the sweep frequency higher limit deducted 1 megahertz, nominal resonant frequency value such as crystal-vibration-chip to be measured is 6 megahertzes, then the sweep frequency higher limit is 6 megahertzes, and the sweep frequency lower limit is 5 megahertzes;
Utilize microprocessor to export control signal to sinusoidal signal generator, make sinusoidal signal generator sine wave output test signal, the sinusoidal wave test signal of sinusoidal signal generator output is loaded on the crystal-vibration-chip to be measured behind the first voltage follow loop and divider resistance, the resonance signal of crystal-vibration-chip to be measured is then followed the loop through second voltage, commutating circuit, filter circuit, behind the level translation loop, be converted to the digital signal input microprocessor by analog to digital converter, utilize microprocessor to measure the oscillation amplitude of crystal-vibration-chip to be measured under the sinusoidal wave test signal of different frequency, and this is carried out normalized;
The concrete steps of normalized are as follows:
1) measures the oscillation amplitude of crystal-vibration-chip to be measured when the frequency of sinusoidal wave test signal is the sweep frequency higher limit, as the full range value of upper limiting frequency benchmark, measure the oscillation amplitude of crystal-vibration-chip to be measured when the frequency of sinusoidal wave test signal is the sweep frequency lower limit, as the full range value of lower frequency limit benchmark;
2) calculate coefficient slope and the intercept of linear relationship between frequency and the full amplitude, specific formula for calculation is:
D1=?k×f1+b
D2=?k×f2+b
Draw:
k?=?（D2-D1）/（f2-f1）
b?=?（f2×D1-f1×D2）/（f2-f1）
Wherein, D1 is the full range value of upper limiting frequency benchmark, and D2 is the full range value of lower frequency limit benchmark, and f1 is the sweep frequency higher limit, and f2 is the sweep frequency lower limit, and k is the coefficient slope, and b is intercept;
3) set the test frequency value, utilize the microprocessor control sinusoidal signal generator output frequency value sinusoidal wave test signal consistent with the test frequency value;
4) utilize microprocessor to measure crystal-vibration-chip to be measured oscillation amplitude when the test frequency value, and according to surveying the oscillation amplitude value, calculating the resistance loss of crystal-vibration-chip to be measured when the test frequency value be:
Z?=?DS/D×100%
D=?k×f+b
Wherein, Z is resistance loss, and DS is actual measurement oscillation amplitude value, and f is the test frequency value, and when test frequency f equaled the resonance frequency of crystal-vibration-chip, then the Z value was exactly the true resistance loss of crystal-vibration-chip.
Fig. 3 is to be the quantitative calculating chart of reactance of the crystal-vibration-chip of 5.9995MHz to a nominal resonant frequency, and the transverse axis among this figure is the frequency number line, and the longitudinal axis is the reactance value axle of crystal-vibration-chip.
As can be seen from Figure 3, at the series resonance frequency place, reactance is 0, it is pure resistive that the impedance of crystal-vibration-chip is, and when slightly departing from nominal resonant frequency, no matter be low frequency or HFS, the crystal-vibration-chip impedance all presents larger capacitive reactance (namely less than 0) very soon, so at these non-nominal resonant frequency point places, because the crystal-vibration-chip impedance is much larger than the resistance value of metering circuit upper end, the voltage drop that is added on the whole metering circuit drops on the crystal-vibration-chip substantially, uses so the voltage amplitude that these Frequency points record also can be used as the full amplitude 100% of normalized benchmark, and can not bring very large deviation.
In the embodiment of the invention, make linear relationship with the full amplitude of sweep frequency higher limit and these two scanning end dot frequencies of sweep frequency lower limit, between the full amplitude operation values in other frequency place and the measured value, maximum deviation is less than 2%.Because resistance loss is a qualitative instrument, do not set up a complete corresponding quantitative relationship between the oscillatory stability of resistance loss and crystal-vibration-chip, have a small amount of deviation and allow.In addition, the resistance loss of this use number percent formal representation, but distribution and the drift characteristic of partial offset circuit elements device parameters, and obtain good self-consistentency.Therefore the components and parts choice of metering circuit is also very large, can be easy to obtain.
Before crystalline substance control instrument dispatches from the factory, in the debugging, should draw coefficient slope k and intercept b, and it is kept at the parameter storage area of brilliant control instrument, during for normal operation.
The R value of crystal-vibration-chip is less, and then the dividing potential drop in crystal-vibration-chip loop is also just less during resonance, and namely the resistance loss value is less, and along with the change of crystal-vibration-chip R value is large, it is large that the resistance loss value also can become.When crystalline substance control instrument is worked, (or install bad, loss this moment is very large), inefficacy or loop open circuit if crystal-vibration-chip approach to lose efficacy, the resistance loss value of crystal-vibration-chip is near 100%; If the short circuit of crystal-vibration-chip loop, then the resistance loss value of crystal-vibration-chip is near 0%.
When if crystal-vibration-chip is installed and the loose contact between the electrode, the resistance value that then is equivalent to connect in the resistance loss measuring circuit (can be measured frequency in quite a few situation, be the problem of not seeing on the frequency), yes becomes large in this reaction on the resistance loss value, whether such crystal-vibration-chip also easy phenomenon of generation rate shakiness in actual film forming procedure installs one of good parameter so the resistance loss value also can be regarded crystal-vibration-chip as.
Claims (4)
1. the crystal-vibration-chip resistance loss metering circuit of a brilliant control instrument, relate to crystal-vibration-chip to be measured, it is characterized in that: this circuit comprises microprocessor, sinusoidal signal generator, and two voltage follow loops, described two voltage follow loops are respectively the first voltage follow loop, second voltage is followed the loop;
Described microprocessor is provided with a control signal output terminal, a measuring-signal input end, and the microprocessor-based control signal output part is received the control signal input end of sinusoidal signal generator;
The input end in described the first voltage follow loop is received the signal output part of sinusoidal signal generator, and the output terminal in the first voltage follow loop is received the input end that second voltage is followed the loop through a divider resistance;
The output terminal that described second voltage is followed the loop is received the measuring-signal input end of microprocessor successively through a commutating circuit, a filter circuit, a level translation loop, an analog to digital converter;
An electrical connection terminal ground connection of described crystal-vibration-chip to be measured, another electrical connection terminates to the input end that second voltage is followed the loop.
2. crystalline substance according to claim 1 is controlled the crystal-vibration-chip resistance loss metering circuit of instrument, it is characterized in that: what described commutating circuit adopted is the full-wave rectification loop.
3. crystalline substance according to claim 1 and 2 is controlled the crystal-vibration-chip resistance loss metering circuit of instrument, it is characterized in that: what described filter circuit adopted is the low-pass filtering loop.
4. crystalline substance according to claim 1 is controlled the measuring method of the crystal-vibration-chip resistance loss metering circuit of instrument, it is characterized in that:
The crystal-vibration-chip to be measured of crystalline substance being controlled instrument separates with the circuit of crystalline substance control instrument, and the nominal resonant frequency value with crystal-vibration-chip to be measured is set as the sweep frequency higher limit again, the sweep frequency higher limit is deducted 1 megahertz after resulting value be set as the sweep frequency lower limit;
Utilize microprocessor to export control signal to sinusoidal signal generator, make sinusoidal signal generator to crystal-vibration-chip sine wave output test signal to be measured, measure the oscillation amplitude of crystal-vibration-chip to be measured under the sinusoidal wave test signal of different frequency by microprocessor, and this is carried out normalized;
The concrete steps of normalized are as follows:
1) measures the oscillation amplitude of crystal-vibration-chip to be measured when the frequency of sinusoidal wave test signal is the sweep frequency higher limit, as the full range value of upper limiting frequency benchmark, measure the oscillation amplitude of crystal-vibration-chip to be measured when the frequency of sinusoidal wave test signal is the sweep frequency lower limit, as the full range value of lower frequency limit benchmark;
2) calculate coefficient slope and the intercept of linear relationship between frequency and the full amplitude, specific formula for calculation is:
D1=?k×f1+b
D2=?k×f2+b
Draw:
k?=?（D2-D1）/（f2-f1）
b?=?（f2×D1-f1×D2）/（f2-f1）
Wherein, D1 is the full range value of upper limiting frequency benchmark, and D2 is the full range value of lower frequency limit benchmark, and f1 is the sweep frequency higher limit, and f2 is the sweep frequency lower limit, and k is the coefficient slope, and b is intercept;
3) set the test frequency value, utilize the microprocessor control sinusoidal signal generator output frequency value sinusoidal wave test signal consistent with the test frequency value;
4) utilize microprocessor to measure crystal-vibration-chip to be measured oscillation amplitude when the test frequency value, and according to surveying the oscillation amplitude value, calculating the resistance loss of crystal-vibration-chip to be measured when the test frequency value be:
Z?=?DS/D×100%
D=?k×f+b
Wherein, Z is resistance loss, and DS is actual measurement oscillation amplitude value, and f is the test frequency value.
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| CN111290660A (en) * | 2020-01-21 | 2020-06-16 | 上海悦易网络信息技术有限公司 | Method and equipment for converting screen coordinates into touch pen coordinates |
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