CN202748307U - System for measuring thin film Young modulus - Google Patents
System for measuring thin film Young modulus Download PDFInfo
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- CN202748307U CN202748307U CN 201220358188 CN201220358188U CN202748307U CN 202748307 U CN202748307 U CN 202748307U CN 201220358188 CN201220358188 CN 201220358188 CN 201220358188 U CN201220358188 U CN 201220358188U CN 202748307 U CN202748307 U CN 202748307U
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Abstract
The utility model discloses a system for measuring a thin film Young modulus. The system comprises a pulsed laser. The pulsed laser transmits pulse laser and after the pulsed laser is straightened and expanded for beams through a first expanding beam mirror. The pulse laser is divided into 7/10 pulse laser and 3/10 pulse laser through a 3/7 spectroscope. The 7/10 pulse laser is focused on a surface of a to-be-detected sample through a cylindrical surface focusing lens and is stimulated to generate acoustic surface wave signals. The acoustic surface wave signals are converted to electrical signals through a first detection channel and /or a second detection channel, and are transmitted to a computer to be processed after the acoustic surface wave signals are displayed through an oscilloscope. The system has the advantages of being not only large in signal amplitude, strong in applicability in a strong disturbance detecting environment, and the like of the piezoelectric laser acoustic surface wave detection technology, but also succeeds advantages of speediness, accuracy, noncontact measurement, high signal to noise ratio (SNR) and the like of the differential confocal laser acoustic surface wave detection technology, and is stronger in applicability and wider in range of application. At the same time, on the basis of an advantage of high measuring bandwidth of the differential confocal laser acoustic surface wave detection technology, measuring distinguishability is greatly improved.
Description
Technical field
The utility model relates to the Young modulus field that utilizes Laser Ultrasonic Technique to measure film, relates in particular to a kind of system for the measurement of film Young modulus.
Background technology
In recent years, Laser Ultrasonic Technique is obtaining extensive concern aspect the measuring mechanical characteristics such as film Young modulus, and in laser ultrasonic system, the surface acoustic wave Detection Techniques emerge in an endless stream.In the present technology, based on the PVDF(Kynoar) the piezoelectricity laser sonic surface wave detection technique of film is the technology that widely adopts, PVDF piezoelectric membrane acoustic impedance matching properties is good, responsive bandwidth is large, power electricity converting sensitivity advantages of higher, so that have Measurement bandwidth (up to 120MHz) far above general Systems for optical inspection based on the piezoelectricity laser sonic surface wave detection system of PVDF film, and has excellent Measurement sensibility (the uncertainty of measurement error is ± 1%).
Based on the responsive difference confocal laser surface acoustic wave detection technique that detects of light deflection be during the optical non-contact surface acoustic wave detects faster, accurately and the higher measuring technique of degree of accuracy, the light deflection sensitivity detects the system that guaranteed and has high sensitivity and the quick ability of response in this technology; Measurement bandwidth is extended to 300MHz, has improved the resolution characteristic of system to the high-frequency sound surface wave signal; Adopt the sample of signal of differential type, eliminated the common mode interference such as the fluctuation of detector luminous power, surrounding air convection current and electronic noise, improved the signal to noise ratio (S/N ratio) of system; And this technology is not damaged, non-contact measurement, is specially adapted to the ultra-clean test environment that integrated circuit etc. requires.
Above-described two kinds of surface acoustic wave detection techniques, although aspect the measurement of film Young modulus, have excellence in the characteristic of other detection techniques, in some particular sample, respectively there is weak point special screne test aspect.For example: based on the piezoelectric effect device (publication number: CN102252967A of PVDF piezoelectric membrane LSAW location, open day: the four-quadrant surface acoustic wave of announcing on November 23rd, 2011) detected, although it has improved measuring accuracy to a certain extent, but it remains contact measurement, can not be used for measure the sample that material is soft, porosity is high, and be difficult to the super-clean environment that is applicable to require in the integrated circuit; LSAW positioning measurment system (publication number: CN102221397A based on the Sagnac interferometer, open day: that announces on October 19th, 2011) located first the method that detects afterwards, although can accurately locate in time the position of surface acoustic wave, thereby carry out more high-precision measurement, but it is based on the non-contact measurement of optics all the time, can not be used for measure the sample that reflection coefficient is low, transparency is high, and easily be subject to the impact that noise in the environment etc. disturbs.
The utility model content
The utility model provides a kind of system of measuring for the film Young modulus, and the utility model has been realized under different scenes the measurement of different samples has been realized cross validation, has avoided the impact of noise, sees for details hereinafter and describes:
A kind of system for the measurement of film Young modulus, comprise: pulsed laser, described pulsed laser emission pulse laser is behind the first beam expanding lens collimator and extender, be divided into 7/10 pulse laser and 3/10 pulse laser by the 3:7 spectroscope, described 7/10 pulse laser excites to produce the surface acoustic wave signal through the surface of cylindrical focusing lens focus at sample;
Described surface acoustic wave signal is converted to electric signal through the first sense channel and/or the second sense channel, and processes by being transferred to computing machine behind the oscilloscope display.
Described the first sense channel comprises: piezoelectric probe,
After PVDF piezoelectric film sensor under the described piezoelectric probe detects described surface acoustic wave signal, described surface acoustic wave signal is converted to described electric signal; Described 3/10 pulse laser triggers photodiode as trigger pip, exports described electric signal to amplifier by wire, and the signal after the filtered amplification arrives described oscillograph, and described oscillograph obtains described electric signal.
Described the second sense channel comprises: the He-Ne laser instrument of 632.8nm,
The He-Ne laser instrument of described 632.8nm sends detection light, behind the second beam expanding lens collimator and extender, produced transmitted light by the polarization of 1:1 polarization spectroscope, described transmitted light focuses on the surface of sample behind the first plane mirror, λ/4 wave plates and the first condenser lens, obtain behind the described surface acoustic wave signal through producing reflected light behind described the first condenser lens, described λ/4 wave plates, described the first plane mirror and the described 1:1 polarization spectroscope, described reflected light transfers to the 1:1 spectroscope and is divided into first via reflected light and the second road reflected light; Described first via reflected light enters a detection mouth of difference photodetector behind the second plane mirror, the first diaphragm, the second condenser lens and the first optical filter; Described the second road reflected light enters another detection mouth of described difference photodetector behind the 3rd plane mirror, the second diaphragm, the 3rd condenser lens and the second optical filter; Described difference photodetector is exported described electric signal and is transferred to described oscillograph, and described oscillograph obtains described electric signal.
Described the first optical filter and described the second optical filter are specially: wavelength is the spike interference filter of 632.8nm.
The beneficial effect of the technical scheme that the utility model provides is: this system not only have piezoelectricity laser sonic surface wave detection technique signal amplitude large, in the large test environment of disturbance the advantages such as applicability is strong, also inherited difference confocal laser surface acoustic wave detection technique fast, accurately, the advantages such as non-cpntact measurement and signal to noise ratio (S/N ratio) height, applicability is stronger, and the scope of application is wider.Simultaneously, based on the advantage of difference confocal laser surface acoustic wave detection technique high measurement bandwidth, integrated system has the Measurement bandwidth higher than conventional measurement techniques, has greatly improved Measurement Resolution, has following advantage:
1. inherited the advantage of the confocal two kinds of LSAW detection techniques of piezoelectricity and difference, two sense channels respectively have weak point when using separately, can mutually remedy deficiency separately after integrated, performance advantage separately, make measurement effect reach optimum, table 1 has been listed the relative merits of two detection techniques.
2. two sense channels are arranged, and the user is the detection mode of the applicable specific sample of flexible choice and scene as the case may be, has listed sample and the test scene of two each self application of passage in the table 2.
3. the sample and the test scene that are suitable for simultaneously for two sense channels can be realized the real-time, interactive checking, guarantee measurement result accurately and reliably; The surface acoustic wave signal can directly obtain the measurement result of film Young modulus after treatment, need not to compare with traditional nano-hardness tester measurement result again, has simplified film Young modulus measuring process.
4. repeatable detection, under the condition that condition does not change, the identical sample of duplicate measurements can obtain identical Wave data.
Description of drawings
The structural representation of a kind of system of measuring for the film Young modulus that Fig. 1 provides for the utility model.
In the accompanying drawing, the list of parts of each label representative is as follows:
1: pulsed laser; 2: the first beam expanding lenss;
The 3:3:7 spectroscope; 4: the cylindrical focusing lens;
5: sample; 6: objective table;
The 7:He-Ne laser instrument; 8: the second beam expanding lenss;
The 9:1:1 polarization spectroscope; 10: the first plane mirrors;
11: λ/4 wave plates; 12: the first condenser lenses;
The 13:1:1 spectroscope; 14: the second plane mirrors;
15: the first diaphragms; 16: the three plane mirrors;
17: the second diaphragms; 18: the second condenser lenses;
19: the three condenser lenses; 20: the first optical filters;
21: the second optical filters; 22: the difference photodetector;
23: piezoelectric probe; The 24:PVDF piezoelectric film sensor;
25: amplifier; 26: photodiode;
27: oscillograph; 28: computing machine.
Embodiment
For making the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with accompanying drawing the utility model embodiment is described in further detail.
In order to realize under different scenes the measurement to different samples, realize cross validation, avoid the impact of noise, the utility model embodiment provides a kind of system of measuring for the film Young modulus, referring to Fig. 1, sees for details hereinafter and describes:
A kind of system for the measurement of film Young modulus, comprise: pulsed laser 1, pulsed laser 1 emission pulse laser is behind the first beam expanding lens 2 collimator and extenders, be divided into two parts by 3:7 spectroscope 3,7/10 pulse laser and 3/10 pulse laser, 7/10 pulse laser focuses on the surface of sample 5 through cylindrical focusing lens 4, excite to produce the surface acoustic wave signal; The surface acoustic wave signal is converted to electric signal through the first sense channel and/or the second sense channel, and processes by being transferred to computing machine 28 after oscillograph 27 demonstrations.
During specific implementation, realized that by the first sense channel PVDF piezoelectric membrane surface acoustic wave detects; Realized that by the second sense channel the confocal surface acoustic wave of difference detects.
Wherein, during specific implementation, tested article 5 are placed on the objective table 6.
Wherein, 28 pairs of electric signal of computing machine carry out computing, realize the measurement to the film Young modulus, and concrete calculation procedure is conventionally known to one of skill in the art, and the utility model embodiment does not do at this and gives unnecessary details.
Wherein, the first sense channel comprises: piezoelectric probe 23, after the PVDF piezoelectric film sensor 24 under the piezoelectric probe 23 detects the surface acoustic wave signal, the surface acoustic wave signal is converted to electric signal, and then be exaggerated device 25 filter and amplifications; 3/10 pulse laser triggers photodiode 26 as trigger pip, exports electric signal to amplifier 25 by wire, and the signal after the filtered amplification arrives oscillograph 27, and oscillograph 27 obtains electric signal.
Wherein, the second sense channel comprises: the He-Ne laser instrument 7 of 632.8nm, 632.8nm He-Ne laser instrument 7 send detection light, behind the second beam expanding lens 8 collimator and extenders, produced transmitted light by 9 polarization of 1:1 polarization spectroscope, transmitted light is through the first plane mirror 10, focus on the surface of sample 5 behind λ/4 wave plates 11 and the first condenser lens 12, obtain behind the surface acoustic wave signal through the first condenser lens 12, λ/4 wave plates 13, the first plane mirror 10 and 1:1 polarization spectroscope 9 rear generation reflected light, reflected light transfers to 1:1 spectroscope 13 and is divided into first via reflected light and the second road reflected light; First via reflected light enters a detection mouth of difference photodetector 22 behind the second plane mirror 14, the first diaphragm 15, the second condenser lens 18 and the first optical filter 20; The the second road reflected light enters another detection mouth of difference photodetector 22 behind the 3rd plane mirror 16, the second diaphragm 17, the 3rd condenser lens 19 and the second optical filter 21; Difference photodetector 22 output electrical signals also transfer to oscillograph 27, and oscillograph 27 obtains electric signal.
Wherein, can regulate diameter and the incident intensity of incident beam by the first diaphragm 15 and the second diaphragm 17.
Further, in order to eliminate the impact of parasitic light, the first optical filter 20 and the second optical filter 21 are preferably: wavelength is the spike interference filter of 632.8nm.
Wherein, when realizing that by the second sense channel the confocal surface acoustic wave of difference detects, at first to regulate the position of the second plane mirror 14 and the 3rd plane mirror 16, guarantee that first via reflected light has identical optical path difference with the second road reflected light, then by regulating the position of 1:1 spectroscope 13, the two-beam that enters difference photodetector 22 is equated by force, amplify difference channel because difference photodetector 22 inside are broadbands, so at this moment output signal is zero.When the focusing He-Ne spot area on the sample 5 has the surface acoustic wave process, folded light beam produces the trace skew because reflection angle changes, cause the catoptrical intensity that two bundles incide difference photodetector 22 to change, corresponding output also changes, thereby can detect the ultrasonic surface wave on the sample 5.
The relative merits of table 1 liang detection technique
Sample and the test scene of table 2 liang each self application of sense channel
Its workflow is when realizing that by the first sense channel PVDF piezoelectric membrane surface acoustic wave detects:
Pulsed laser 1 emission pulse laser is behind the first beam expanding lens 2 collimator and extenders, be divided into two parts by 3:7 spectroscope 3,7/10 pulse laser and 3/10 pulse laser, 7/10 pulse laser focus on the surface of sample 5 through cylindrical focusing lens 4, excite to produce the surface acoustic wave signal; After PVDF piezoelectric membrane detector 24 below the piezoelectric probe 23 detects the surface acoustic wave signal, 3/10 pulse laser triggers photodiode 26 as trigger pip, pass through energy conversion, by wire electric signal is outputed to amplifier 25, signal after the filtered amplification arrives oscillograph 27, enters at last computing machine 28 and carries out Electric signal processing.
Its workflow is when realizing that by the second sense channel the confocal surface acoustic wave of difference detects:
Pulsed laser 1 emission pulse laser is behind the first beam expanding lens 2 collimator and extenders, be divided into two parts by 3:7 spectroscope 3,7/10 pulse laser and 3/10 pulse laser, 7/10 pulse laser focus on the surface of sample 5 through cylindrical focusing lens 4, excite to produce the surface acoustic wave signal; Wavelength is the detection light that the He-Ne laser instrument 7 of 632.8nm sends, through being polarized by 1:1 polarization spectroscope 910 behind the first beam expanding lens 8 beam-expanding collimations, make wherein transmitted light behind the first plane mirror 10, λ/4 wave plates 11 and the first condenser lens 12, focus on the surface of sample 5, return by former road after obtaining surface acoustic wave.Because survey the polarisation of light direction and change 90 ° through λ/4 wave plates for twice, when again arriving 1:1 polarization spectroscope 9, transmissive can only not be reflected.This reflected light arrives 1:1 spectroscope 13 and is divided into two-way light, and wherein first via reflected light enters of difference photodetector 22 after through the second plane mirror 14, the first diaphragm 15, the second condenser lens 18 and the first optical filter 20 and surveys mouthful.The the second road reflected light enter difference photodetector 22 after through the 3rd plane mirror 16, the second diaphragms 17, the three condenser lenses 19, the second optical filters 21 another survey mouthful.At last, the output electrical signals of difference photodetector 22 is shown by oscillograph 27, and sends into computing machine 28 and process.
Its workflow is when realizing that by the first sense channel and the second sense channel PVDF piezoelectric membrane surface acoustic wave and the confocal surface acoustic wave of difference detect:
The first sense channel and the second sense channel will be worked simultaneously, when regulating, because the second sense channel is more complicated, at first will regulates the second sense channel according to actual conditions, and then regulate the first sense channel.The electric signal that the first sense channel and the second sense channel detect can be simultaneously shows and stores at oscillograph 27, can intuitively compare the first sense channel and the second sense channel test case to same sample 5 under identical environment.
Wavelength is the detection light that the He-Ne laser instrument 7 of 632.8nm sends, through being polarized by 1:1 polarization spectroscope 9 behind the first beam expanding lens 8 beam-expanding collimations, make wherein transmitted light behind the first plane mirror 10, λ/4 wave plates 11 and the first condenser lens 12, focus on the surface of sample 5, return by former road after obtaining surface acoustic wave.Because survey the polarisation of light direction and change 90 ° through λ/4 wave plates for twice, when again arriving 1:1 polarization spectroscope 9, transmissive can only not be reflected.This reflected light arrives 1:1 spectroscope 13 and is divided into two-way light, and wherein first via reflected light enters of difference photodetector 22 after through the second plane mirror 14, the first diaphragm 15, the second condenser lens 18 and the first optical filter 20 and surveys mouthful.The the second road reflected light enter difference photodetector 22 after through the 3rd plane mirror 18, the second diaphragms 17, the three condenser lenses 19, the second optical filters 21 another survey mouthful.At last, the output electrical signals of difference photodetector 22 is shown by oscillograph 27, and sends into computing machine 28 and process.
In sum, the utility model embodiment provides a kind of system for the measurement of film Young modulus, this this system not only have piezoelectricity laser sonic surface wave detection technique signal amplitude large, in the large test environment of disturbance the advantages such as applicability is strong, also inherited difference confocal laser surface acoustic wave detection technique fast, accurately, the advantages such as non-cpntact measurement and signal to noise ratio (S/N ratio) height, applicability is stronger, and the scope of application is wider.Simultaneously, based on the advantage of difference confocal laser surface acoustic wave detection technique high measurement bandwidth, integrated system has the Measurement bandwidth higher than conventional measurement techniques, has greatly improved Measurement Resolution.
It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, above-mentioned the utility model embodiment sequence number does not represent the quality of embodiment just to description.
The above only is preferred embodiment of the present utility model, and is in order to limit the utility model, not all within spirit of the present utility model and principle, any modification of doing, is equal to replacement, improvement etc., all should be included within the protection domain of the present utility model.
Claims (4)
1. one kind is used for the system that the film Young modulus is measured, comprise: pulsed laser (1), described pulsed laser (1) emission pulse laser is behind the first beam expanding lens (2) collimator and extender, be divided into 7/10 pulse laser and 3/10 pulse laser by 3:7 spectroscope (3), described 7/10 pulse laser focuses on the surface of sample (5) through cylindrical focusing lens (4), excite to produce the surface acoustic wave signal; It is characterized in that,
Described surface acoustic wave signal is converted to electric signal through the first sense channel and/or the second sense channel, and processes by being transferred to computing machine (28) after oscillograph (27) demonstration.
2. a kind of system for the measurement of film Young modulus according to claim 1 is characterized in that, described the first sense channel comprises: piezoelectric probe (23),
After PVDF piezoelectric film sensor (24) under the described piezoelectric probe (23) detects described surface acoustic wave signal, described surface acoustic wave signal is converted to described electric signal; Described 3/10 pulse laser triggers photodiode (26) as trigger pip, exports described electric signal to amplifier (25) by wire, and the signal after the filtered amplification arrives described oscillograph (27), and described oscillograph (27) obtains described electric signal.
3. a kind of system for the measurement of film Young modulus according to claim 1 is characterized in that, described the second sense channel comprises: the He-Ne laser instrument (7) of 632.8nm,
The He-Ne laser instrument (7) of described 632.8nm sends detection light, after crossing the second beam expanding lens (8) collimator and extender, produced transmitted light by 1:1 polarization spectroscope (9) polarization, described transmitted light is through the first plane mirror (10), focus on the surface of sample (5) behind λ/4 wave plates (11) and the first condenser lens (12), obtain behind the described surface acoustic wave signal through described the first condenser lens (12), described λ/4 wave plates (11), produce reflected light behind described the first plane mirror (10) and the described 1:1 polarization spectroscope (9), described reflected light transfers to 1:1 spectroscope (13) and is divided into first via reflected light and the second road reflected light; Described first via reflected light enters a detection mouth of difference photodetector (22) behind the second plane mirror (14), the first diaphragm (15), the second condenser lens (18) and the first optical filter (20); Described the second road reflected light enters another detection mouth of described difference photodetector (22) behind the 3rd plane mirror (16), the second diaphragm (17), the 3rd condenser lens (19) and the second optical filter (21); Described difference photodetector (22) the described electric signal of output also transfers to described oscillograph (27), and described oscillograph (27) obtains described electric signal.
4. a kind of system for the measurement of film Young modulus according to claim 3 is characterized in that, described the first optical filter (20) and described the second optical filter (21) are specially: wavelength is the spike interference filter of 632.8nm.
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| CN 201220358188 CN202748307U (en) | 2012-07-19 | 2012-07-19 | System for measuring thin film Young modulus |
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| CN 201220358188 CN202748307U (en) | 2012-07-19 | 2012-07-19 | System for measuring thin film Young modulus |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102768184A (en) * | 2012-07-19 | 2012-11-07 | 天津大学 | System for Young modulus measurement of film |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102768184A (en) * | 2012-07-19 | 2012-11-07 | 天津大学 | System for Young modulus measurement of film |
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