CN201892570U - Contact resonance frequency detecting system for atomic force acoustic microscope cantilever beam - Google Patents
Contact resonance frequency detecting system for atomic force acoustic microscope cantilever beam Download PDFInfo
- Publication number
- CN201892570U CN201892570U CN2010206410666U CN201020641066U CN201892570U CN 201892570 U CN201892570 U CN 201892570U CN 2010206410666 U CN2010206410666 U CN 2010206410666U CN 201020641066 U CN201020641066 U CN 201020641066U CN 201892570 U CN201892570 U CN 201892570U
- Authority
- CN
- China
- Prior art keywords
- signal
- control panel
- atomic
- vco
- cantilever beam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Landscapes
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
A contact resonance frequency detecting system for an atomic force acoustic microscope cantilever beam is mainly used for detecting the contact resonance frequency of the atomic force acoustic microscope cantilever beam, further realizes the elastic modulus imaging of an atomic force acoustic microscope and belongs to the field of nondestructive detection. In the contact resonance frequency detecting system, based on a voltage signal corresponding to a resonance curve peak of the atomic force acoustic microscope cantilever, the principle that a voltage-controlled oscillator is controlled to output the sinusoidal voltage signal with the resonance center frequency to excite a piezoelectric transducer is applied. The contact resonance frequency detecting system mainly comprises a phase-lock amplifier connected with a photodiode detector of the atomic force acoustic microscope cantilever beam, the voltage-controlled oscillator (VCO) connected with the piezoelectric transducer of the atomic force acoustic microscope and a DSP (digital signal processor) control panel for processing a frequency signal, wherein the DSP control panel is used for controlling the VCO to output the sinusoidal voltage signal with a resonance center frequency for exciting the piezoelectric transducer to obtain a resonance curve and further obtain the center frequency of the resonance curve, and an automatic frequency detection system is realized.
Description
Technical field
The atomic-force acoustic microscopy cantilever beam contact resonance frequency detection system is mainly used in the contact resonance frequency that detects the atomic force microscope semi-girder, and then realizes the elastic modulus imaging of atomic-force acoustic microscopy, belongs to the Non-Destructive Testing field.
Background technology
Atomic-force acoustic microscopy (AFAM) technology is done ultrasonic vibration by the semi-girder or the test specimen that make atomic force microscope, the high frequent vibration mode of excitation cantilever arm beam.Accurately measure the drift of higher order resonances frequency, can reflect test specimen surface local engineering properties well, as contact stiffness, elastic constant, near surface flaw etc.This technology has very high lateral resolution (can less than 10nm), both has been applicable to that the surface of Electronic Packaging solder joint and near surface flaw detected, but the elastic property of MEASUREMENTS OF THIN material again is the new research focus of Non-Destructive Testing circle in recent years.
AFAM generally builds on the atomic force microscope platform.Difference according to driving source can be divided into two classes, sample-AFAM (S-AFAM, sample excitation) and probe-AFAM (T-AFAM, probe excitation).The working method of S-AFAM is meant that AFM is operated in contact mode, and the sample back side is placed on the atomic force microscope support with the bonding piezoelectric transducer of couplant, and driving source is inserted piezoelectric transducer.The working method of T-AFAM is meant that signal generator drive pressure electric transducer produces a continuous vibration signal, this signal penetrates sample and is accepted by the AFM cantilever, when the probe of AFM cantilever touches sample, thereby this weak vibration is propagated the excitation cantilever arm vibration by probe-sample coupling.Detect the vibration signal of cantilever, this signal input lock-in amplifier, the pumping signal of driving source is also imported lock-in amplifier as the reference signal, and signal enters computing machine after lock-in amplifier is handled, and applied analysis software is analyzed and obtained test specimen surface topography map and phase diagram.
Although the AFAM method can reflect test specimen surface local engineering properties well at present, as contact stiffness, elastic constant, near surface flaw etc.But because traditional atomic-force acoustic microscopy system adopts phase-locked or network analysis location technology, actual imaging speed is too slow.In order to obtain contact resonance frequency fast, so that realize quick elastic modulus imaging, need the resonance frequency detection system of exploitation one cover based on DSP, be used for detecting resonance frequency in real time in imaging process.
Summary of the invention
The purpose of this utility model is, to adopt lock-in amplifier or network analyzer to obtain atomic-force acoustic microscopy cantilever beam contact resonance frequency speed slower in order to solve in traditional atomic-force acoustic microscopy technology, and then cause the slow problem of atomic force microscope imaging, a kind of frequency detecting system that obtains atomic-force acoustic microscopy cantilever beam contact resonance frequency fast is provided.
To achieve these goals, the utility model has adopted following scheme: adopt the DSP signal processor, realize a kind of fast automatic system that atomic-force acoustic microscopy cantilever beam contact resonance frequency is detected, mainly comprise DSP control panel, the lock-in amplifier that is connected with the photodiode detector of atomic-force acoustic microscopy cantilever beam, the voltage controlled oscillator VCO that is connected with the piezoelectric sensor of atomic-force acoustic microscopy.Lock-in amplifier extracts the atomic-force acoustic microscopy cantilever beam vibration signal from the signal of photodiode detector output, be input to and carry out signal Processing in the DSP control panel; The DSP control panel is handled the signal of lock-in amplifier input, draws out the frequency spectrum of input signal, obtains the centre frequency of semi-girder; VCO as with the signal excitation source of the piezoelectric sensor of sample coupling, according to the control signal of DSP control panel input, the sinusoidal wave frequency sweep that produces 3kHz～3MHz is to piezoelectric sensor; And the DSP control panel is exported a feedback signal also to VCO according to the centre frequency that obtains, and the centre frequency that this signal adjustment VCO regulates vibration is positioned at the resonance center to keep the semi-girder response curve.
Described DSP control panel comprises dsp chip, A/D analog to digital converter and D/A digital to analog converter, the multi-channel data impact damper, complex programmable logic device (CPLD), synchronous DRAM SDRAM, flash memory FLASH, external clock and serial line interface, the DSP control panel receives the signal of lock-in amplifier input, at first enter and carry out signal Processing in the dsp chip through the A/D analog to digital converter, the frequency of operation of dsp chip is provided by external clock, the work schedule of CPLD control system, carry out the outer data storage of sheet by FLASH and SDRAM, dsp chip is by serial line interface and external device communication, data after the signal Processing are through the D/A digital to analog converter, be transformed into simulating signal, be input among the VCO.And one tunnel duty cycle adjustment circuit is set is connected to VCO, thereby regulate the dutycycle of VCO output signal.
Can set up host computer, this host computer is communicated by letter with dsp chip by serial line interface, is provided with alternating interface between man and computer in the host computer, can show tuning curve according to the information that the DSP control panel transmits, and can set and regulate parameter to the DSP control panel.
In addition,, also be sent to the auxiliary imaging input port of atomic force microscope from the feedback information of the adjustment VCO centre frequency of DSP control panel output, be depicted as one with the proportional image of resonance frequency.
The utility model is based on the voltage signal of atomic force microscope cantilever resonance peak correspondence, adopt the sine voltage signal excitation piezoelectric sensor of advanced DSP signal processor control voltage controlled oscillator export resonance centre frequency, obtain tuning curve, and then obtain the centre frequency of tuning curve, realized a kind of fast automatic frequency detecting system.
Description of drawings
The work synoptic diagram of Fig. 1 voltage controlled oscillator;
The structured flowchart of Fig. 2 atomic-force acoustic microscopy cantilever beam contact resonance frequency detection system one preferred embodiment;
DSP control panel structural representation during Fig. 3 is embodiment illustrated in fig. 2
The DSP control panel is to the process flow diagram of atomic-force acoustic microscopy cantilever beam vibration frequency signal Processing in Fig. 4 the utility model.
Embodiment
Signal excitation source as piezoelectric sensor in the utility model is a voltage controlled oscillator (VCO), to voltage signal of VCO input, the sine wave of VCO output certain frequency, the amplitude of increase input voltage signal, the sinusoidal wave frequency of corresponding VCO output also increases.The peripheral condition that needs during VCO work as shown in Figure 1.At first the DSP control panel is exported a frequency sweep signal (be voltage magnitude change signal) to VCO, VCO is produced sweep sine, encourages piezoelectric sensor.Then the DSP control panel by A/D sampling, signal Processing after, the voltage signal of feedback semi-girder resonance centre frequency correspondence is to VCO, VCO produces the sinusoidal signal excitation piezoelectric sensor under the resonance frequency.Other has one tunnel duty cycle adjustment circuit, the dutycycle of scalable VCO output signal.
2-4 is further described the utility model by specific embodiment below in conjunction with accompanying drawing, and following examples are descriptive, is not determinate, can not limit protection domain of the present utility model with this.The general structure block diagram of present embodiment as shown in Figure 2, the concrete course of work is as follows:
1) send swept-frequency signal in the DSP control panel (DSP signal Processing A), control VCO (piezoelectric oscillator B) produces the adjustable frequency sweep sine wave of an amplitude and is delivered to piezoelectric sensor C, and piezoelectric sensor C goes up and places sample D.
2) this signal penetrates sample and is accepted by the semi-girder among the atomic force microscope E.When the probe on the semi-girder touches sample D, thereby this weak vibration is propagated the excitation cantilever arm vibration by probe-sample coupling.Photodiode detector detects the Oscillation Amplitude of semi-girder, and this signal is delivered to lock-in amplifier F.
3) lock-in amplifier F extracts the atomic-force acoustic microscopy cantilever beam vibration signal from the signal of photodiode detector output, converts thereof into direct current signal, is input to and carries out signal Processing in the DSP control panel.The DSP control panel reads this signal, stores.After each scanning is finished, make up a complete tuning curve, find the peak value in the tuning curve.And this information delivered to VCO with the form of voltage signal by a feedback control loop, adjust the centre frequency that VCO regulates vibration and be positioned at the resonance center to keep the cantilever response curve.
4) be used to regulate the feedback voltage signal of the centre frequency of VCO, also be sent to the imaging port G of atomic force microscope, be depicted as one with the proportional image of resonance frequency.
5) also be provided with main frame H, main frame H communicates by letter with the DSP control panel, and host computer H can show tuning curve according to the information that the DSP control panel transmits, and is provided with alternating interface between man and computer, can set and regulate parameter to the DSP control panel.
Kernal hardware of the present utility model is the DSP control panel, comprises devices such as dsp chip, A/D, D/A, multi-channel data impact damper, CPLD, SDRAM, FLASH, external clock and serial line interface, and DSP control panel structure as shown in Figure 3.At first the signal of lock-in amplifier input enters through the A/D analog to digital conversion and carries out signal Processing in the dsp chip, and the frequency of operation of dsp chip is provided by external clock, the work schedule of CPLD control system.Carry out the outer data storage of sheet by FLASH and SDRAM.Dsp chip is communicated by letter with host computer by serial line interface, and the data after the signal Processing are transformed into simulating signal through the D/A digital-to-analog conversion, are input among the VCO.
Core technology of the present utility model mainly is, the DSP control panel reads the atomic force microscope cantilever tuning curve signal that extracts through lock-in amplifier, find its peak value, and the corresponding with it voltage signal of feedback, the sine voltage signal excitation piezoelectric sensor of control VOD export resonance centre frequency has been realized a kind of fast automatic frequency detecting scheme.The signal processing flow figure of DSP control panel, as shown in Figure 4.
Claims (5)
1. atomic-force acoustic microscopy cantilever beam contact resonance frequency detection system, mainly comprise DSP control panel, the lock-in amplifier that is connected with the photodiode detector of atomic-force acoustic microscopy cantilever beam, the voltage controlled oscillator VCO that is connected with the piezoelectric sensor of atomic-force acoustic microscopy, it is characterized in that: lock-in amplifier extracts the atomic-force acoustic microscopy cantilever beam vibration signal from the signal of photodiode detector output, be input to and carry out signal Processing in the DSP control panel; The DSP control panel is handled the signal of lock-in amplifier input, draws out the frequency spectrum of input signal, obtains the centre frequency of semi-girder; VCO as with the signal excitation source of the piezoelectric sensor of sample coupling, according to the control signal of DSP control panel input, the sinusoidal wave frequency sweep that produces 3kHz～3MHz is to piezoelectric sensor; And the DSP control panel is exported a feedback signal also to VCO according to the centre frequency that obtains, and the centre frequency that this signal adjustment VCO regulates vibration is positioned at the resonance center to keep the semi-girder response curve.
2. atomic-force acoustic microscopy cantilever beam contact resonance frequency detection system as claimed in claim 1, it is characterized in that: described DSP control panel comprises dsp chip, A/D analog to digital converter and D/A digital to analog converter, the multi-channel data impact damper, complex programmable logic device (CPLD), synchronous DRAM SDRAM, flash memory FLASH, external clock and serial line interface, the DSP control panel receives the signal of lock-in amplifier input, at first enter and carry out signal Processing in the dsp chip through the A/D analog to digital converter, the frequency of operation of dsp chip is provided by external clock, the work schedule of CPLD control system, carry out the outer data storage of sheet by FLASH and SDRAM, dsp chip is by serial line interface and external device communication, data after the signal Processing are through the D/A digital to analog converter, be transformed into simulating signal, be input among the VCO.
3. atomic-force acoustic microscopy cantilever beam contact resonance frequency detection system as claimed in claim 2, it is characterized in that: set up host computer, this host computer is communicated by letter with dsp chip by serial line interface, be provided with alternating interface between man and computer in the described host computer, can show tuning curve according to the information that the DSP control panel transmits, and can set and regulate parameter to the DSP control panel.
4. atomic-force acoustic microscopy cantilever beam contact resonance frequency detection system as claimed in claim 1 is characterized in that: is provided with one tunnel duty cycle adjustment circuit and is connected to VCO, thus the dutycycle of adjusting VCO output signal.
5. as each described atomic-force acoustic microscopy cantilever beam contact resonance frequency detection system among the claim 1-4, it is characterized in that: from the feedback information of the adjustment VCO centre frequency of DSP control panel output, also be sent to the auxiliary imaging input port of atomic force microscope, be depicted as one and the proportional image of resonance frequency.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206410666U CN201892570U (en) | 2010-11-26 | 2010-11-26 | Contact resonance frequency detecting system for atomic force acoustic microscope cantilever beam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206410666U CN201892570U (en) | 2010-11-26 | 2010-11-26 | Contact resonance frequency detecting system for atomic force acoustic microscope cantilever beam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201892570U true CN201892570U (en) | 2011-07-06 |
Family
ID=44222044
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010206410666U Expired - Lifetime CN201892570U (en) | 2010-11-26 | 2010-11-26 | Contact resonance frequency detecting system for atomic force acoustic microscope cantilever beam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201892570U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107192857A (en) * | 2016-03-14 | 2017-09-22 | 中国科学院沈阳自动化研究所 | A kind of nano film thickness detection means and its method based on ultrasonic AFM |
-
2010
- 2010-11-26 CN CN2010206410666U patent/CN201892570U/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107192857A (en) * | 2016-03-14 | 2017-09-22 | 中国科学院沈阳自动化研究所 | A kind of nano film thickness detection means and its method based on ultrasonic AFM |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101839924B (en) | Atomic-force acoustic microscopy cantilever beam contact resonance frequency tracking system | |
| CN101493397B (en) | Electrostatic force microscope and measurement method thereof | |
| US7584653B2 (en) | System for wide frequency dynamic nanomechanical analysis | |
| Belyaev et al. | Crack detection and analyses using resonance ultrasonic vibrations in full-size crystalline silicon wafers | |
| CN102221401A (en) | Vibration test stand and testing method for vibration sensor | |
| US8869311B2 (en) | Displacement detection mechanism and scanning probe microscope using the same | |
| CN101329247B (en) | Combined microscope for scanning atomic force and tunnel current under atmosphere | |
| JPH01106902A (en) | Method and device for testing rotary vane of turbine | |
| CN101469978B (en) | Adjustable automatic wave amplitude gain compensation method and circuit for ultrasonic thickness gauge | |
| CN107228990A (en) | The method of testing and test device of piezoelectric piezoelectric modulus | |
| CN101776436A (en) | Quartz tuning fork-based nano measuring head and sample surface micro-topography measuring method | |
| CN104155477A (en) | Method of tracking atomic force acoustical microscopy probe contact resonant frequency | |
| Zhang et al. | A new method to enhance the tip vibration amplitude output of the high frequency piezoelectric ultrasonic transducer used in the thermosonic bonding | |
| CN102692523A (en) | Method of measuring vibration characteristics of cantilever | |
| CN202101831U (en) | Vibration testing bench | |
| CN201892570U (en) | Contact resonance frequency detecting system for atomic force acoustic microscope cantilever beam | |
| CN113533519B (en) | Method and device for non-contact nondestructive evaluation of anisotropy of material | |
| CN201780308U (en) | Contact resonance frequency tracking system for cantilever beam of atomic force acoustic microscope (AFAM) | |
| KR102577416B1 (en) | Atomic force microscopy and how to perform atomic force microscopy using an atomic force microscope | |
| CN204008099U (en) | Damping clad plate damping capacity proving installation | |
| CN112964242A (en) | System and method for testing mechanical coupling error of quartz tuning fork gyroscope gauge head | |
| Fu et al. | A macroscopic non-destructive testing system based on the cantilever-sample contact resonance | |
| WO2020191704A1 (en) | Composite material dynamic fatigue testing device and method based on reverse resonance | |
| Maali et al. | Precise damping and stiffness extraction in acoustic driven cantilever in liquid | |
| CN115791596A (en) | 3D laser vibration measurement-based interface damage comprehensive test system and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20110706 |