CN103471905B - For single-axis bidirectional micro mechanics measurement mechanism and the measuring method of scanning microscopy environment - Google Patents

Abstract

The invention belongs to micro nanometer mechanics and precision optical machinery field, particularly a kind of single-axis bidirectional micro mechanics measurement mechanism and measuring method for scanning microscopy environment. This device is installed the three-dimensional mobile precision surface plate of fine tuning and the sample platform of the three-dimensional coarse adjustment translation stage of symmetrical co-ordinate-type, symmetry on body supports unit, by control system and actuation unit control operation, can complete the detection of micro-nano characteristic dimension material and structural mechanical property, realize unidirectional centering stretching, compression, bending and vibration measurement, and the distortion of micro-nano-scale specimen surface and Microstructure Evolution detection; Device can repeatedly use, and can realize in conjunction with digital picture/speckle correlation technique, image processing techniques or micro-labelling technique original position distortion and the mechanical property detection of the sample under high-space resolution scanning microscopy environment.

Description

Uniaxial bidirectional micromechanical measurement device and measurement method for scanning microenvironment

technical field

The invention belongs to the field of micro-nano mechanics and precision machinery, and in particular relates to a single-axis bidirectional micro-mechanical measuring device and a measuring method for scanning a micro-environment.

Background technique

As an important part of the field of micro-nano science, micro-nano mechanical experiments play an important and irreplaceable role in the detection and verification of the mechanical properties of micro-nano-scale materials, structures and devices. Its initial requirements come from the research requirements on the mechanical properties of small-scale materials, from the prediction and analysis of the performance and reliability of MEMS and other micro-scale devices, and from the fine, multi-scale models that can describe the mechanical behavior of complex structural materials verification. In particular, due to the reduction of the characteristic size of materials and structures, new mechanical, physical, and processing properties can be changed, and the mechanical properties can be directly detected and characterized at the micron to nanometer scale, and then obtained when the material Or the change in the mechanical properties of a structure after its external dimensions and internal microstructural features are drastically reduced. Since the 1980s, mechanics has made important progress in the theory and calculation of the mesoscopic, microscopic, and nanoscale properties and behaviors of materials and structures. Compared with theoretical analysis and numerical calculation, the progress of mechanical experiments at the micro-nano scale is much more difficult, because experiments at this scale require complete and clear detection principles and methods, as well as basic experimental techniques and methods. Detection equipment, which is a very challenging subject at small scales. Therefore, in the field of experimental detection, even today, it is still extremely difficult to detect the characteristic scale of objects below submicron.

Obviously, no matter in terms of size, function, or clamping, loading and manipulation, for such a tiny research object, macroscopic detection equipment cannot meet this new demand. The research object has the characteristics of small scale, complex performance, and strong coupling interaction with the detection system and the environment, which makes micro-nano experimental mechanics face many challenges.

Faced with the needs of basic research and high-tech applications, on the one hand, the manufacturer has studied the general small-scale experimental machine that is relatively lagging in terms of function and performance according to the needs of many users, such as: suitable for optical microscopy systems and SEM environmental chambers British Gatan mechanical module, American Tytron250 micro-dynamic and static testing machine suitable for fibers and small-scale samples, and American MTS NanoBionix testing machine mainly used for biomedical materials, etc. Although these testing machines are closer to the micro-scale in terms of load, displacement range and resolution compared with the previous macro testing machines, they still mainly use the principle of traditional material testing machines. And the displacement is much larger than the required range of micro-nano materials, and the equipment is expensive. On the other hand, in view of the difficulties of commercial experimental machines, researchers at home and abroad have developed some experimental devices for the mechanical properties of micro-nano materials with more advanced functions and performances according to their own needs. The system is not a complete material testing machine, and most of them are temporary construction systems, which can only complete part of the mechanical performance measurement unit). This kind of material mechanical property detection device or system developed by researchers earlier is relatively cheap and suitable for the mechanical property detection of some special materials or structures, but most of the devices can only work under the optical microscope platform and cannot It meets the mechanical performance testing of materials and structures at the micro-nano scale, let alone the requirements for clamping and manipulating microstructures under the conditions of micro-nano scale testing.

Contents of the invention

The purpose of the present invention is to provide a single-axis bidirectional micromechanical measurement device for scanning the microscopic environment based on the high-spatial microscopic imaging environment of the scanning electron microscope (SEM) or the optical microscope (OM), which can be used to study microscopic The mechanical properties of nanoscale feature-scale films, wires, wires and other specimens under uniaxial tension, compression, bending and other conditions.

The technical scheme adopted in the present invention is:

The integral support unit is installed on the base of the SEM sample stage, and a round hole is set in the center of the upper surface, and a stretchable SEM sample stage is installed in the hole, and the three-dimensional coordinate translation stage and the integral support unit are respectively arranged on the symmetrical positions on both sides to connect the substrate;

Each three-dimensional coordinate translation platform and the overall support unit connection substrate are respectively installed with a coordinate three-dimensional coarse adjustment translation platform composed of X-direction translation piezoelectric guide rails, Y-direction translation piezoelectric guide rails, and Z-direction translation piezoelectric guide rails; Z-direction translation piezoelectric guide rails The upper end of the guide rail is fixedly connected to the connecting arm of the coarse adjustment platform, and the connecting arm of the coarse adjustment platform is connected to the fine adjustment piezoelectric ceramic three-dimensional mobile platform through a piezoelectric sleeve; the front end of the fine adjustment piezoelectric ceramic three-dimensional mobile platform passes through the sensor and the fine adjustment translation platform The connecting sleeve is connected with the sensor, and the front end of the sensor is fixedly connected with the sample platform.

The integral support unit is fixedly connected to the base of the SEM sample stage by three internal screws and two positioning pins.

The X-direction translation piezoelectric guide rail, the Y-direction translation piezoelectric guide rail, and the Z-direction translation piezoelectric guide rail are respectively composed of a one-dimensional piezoelectric motor and a guide rail.

The sample platform is a planar symmetrical loading end, a V-shaped loading end or a probe-shaped loading end, and a corresponding compression and fixing structure is configured.

Based on said device, the present invention also provides a kind of measuring method, carries out as follows:

(a) According to the sample feature size, adjust the sample platform in the optical or SEM imaging environment to be centered, straight, and locked after the axis is consistent; adjust the sample platform to achieve a suitable initial loading distance; in the optical microscope or SEM cavity Complete the sample clamping and installation, and ensure that the long axis of the sample coincides with the tensile axis of the SEM sample stage during installation;

(b) Adjust the detection platform position, magnification, imaging and image acquisition system of the scanning microscope system and make it in the detection state, then drive the device to perform a uniaxial bidirectional micro-tension test on the specimen, and scan the image through the SEM at the same time Record the sequential deformation images of the sample detection area;

(c) Perform digital image processing and micro-marker analysis on the obtained sequential deformation images to obtain the deformation evolution of the surface microstructure in the detection area during the uniaxial biaxial stretching process; at the same time, combine the micro force sensor to obtain the corresponding The force-displacement or stress-strain curve of the test sample, as well as other mechanical performance parameters can be obtained, and combined with the knowledge and theory of the microstructure and micromorphology of the tensile material.

In the step (a), when the sample is a large-scale sample and the sample is installed in an optical microscopic environment, use glue to bond the two ends of the sample to a symmetrical sample platform for curing, and then measure the entire The device was put into the SEM environment chamber to complete subsequent operations and measurements.

In the step (a), when the sample is a micro-nano sample, put the sample platform with the centered and straight device into the SEM environment chamber, observe through SEM imaging, and use the auxiliary manipulation equipment to detect the micro-nano The specimen is added to the specimen platform and fixed by electron beam deposition welding (EBID).

Compared with the prior art, the present invention has the following advantages:

(1) Usually, due to the very limited scanning area of the high-magnification microscope, its small field of view makes the detection area quickly exceed the field of view and cannot achieve continuous detection during the entire loading process. The invention realizes two-way symmetrical loading by designing a three-dimensional coordinate mechanical adjustment structure that ensures that the axes of the two stages are consistent and in the same horizontal plane, and a single-axis two-way drive system for two moving platforms, and is suitable for small fields of view of high spatial resolution microscopic systems The feature ensures that the film scanning area of interest is always in the field of view of the microscopic system during the entire stretching process, so that the continuous detection of the evolution of the microstructure characteristics of the detection sample surface in the micro detection area can be completed.

(2) Through the application of two driving devices, the piezoelectric motor and the piezoelectric ceramic tube, two modes of coarse and fine loading can be realized, which provides the mechanical measurement of the material or structure with the characteristic scale of the detection object ranging from hundreds of microns to tens of nanometers. Guaranteed loading and positioning.

(3) In order to achieve effective and precise mechanical measurement, clamping and manipulation of micro-nano scale samples, two types of stages are designed, one is platform type and the other is probe type, which can be respectively It is suitable for the measurement, clamping, loading and manipulation of micro-nano-scale samples such as thin films, silks, wires, tubes and columns. At the same time, in order to adapt to the installation of small-scale samples and the adjustment of the device, the device system also includes auxiliary micro-sample clamping and manipulation units, centering of the sample stage and adjustment of reference fixtures, etc., to effectively solve the problem. The installation of the micro-sample, the adjustment of the stage in the horizontal plane and the alignment of the axis of the sample and the axis of the stage are solved.

(4) Compared with the existing micro-tensile loading device that integrates chip-type film specimens and clamping structures under the electron beam scanning microscope system, this detection device can be used multiple times, and can be suitable for different properties, The detection of the size of microscale materials and structures greatly expands the range of applications of the device. Combining digital image processing and other related technologies can realize the deformation and evolution detection of micro-scale sample surface microstructure in high spatial resolution microscopic environment, and it can also be adapted to continuous detection of large deformation and complex shape features.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of a coordinate type uniaxial bidirectional stretching device;

Labels in the figure:

1-X direction translation piezoelectric guide rail; 2-Y direction translation piezoelectric guide rail; 3-Z direction translation piezoelectric guide rail; 4-coarse adjustment platform connecting arm; 5-piezoelectric sleeve; Mobile platform; 7-Sensor and fine-tuning translation platform connecting sleeve; 8-Sensor; 9-Sample platform; 10-Sample; Screw; 13-integral support unit; 14-SEM sample stage base; 15-SEM sample stage; 16-location pin.

detailed description

The present invention provides a kind of uniaxial bidirectional micromechanical measurement device and measurement method for scanning microenvironment. The uniaxial bidirectional tension detection under SEM microsystem is taken as an example below, and the principles and details of the present invention are explained in conjunction with the accompanying drawings. The structure and tensile testing method are further explained.

As shown in Figure 1, the overall support unit 13 is a rectangular aluminum alloy plate (175mm×95mm×7mm), the surface is sprayed with silver metal paint, the overall support unit 13 is installed on the base 14 of the SEM sample stage, and there are two passes between the two. 16 positioning pins, 3 M4-20 inner hexagon screws 12 are connected. A circular hole with a diameter of 48 mm is provided at the center of the upper surface of the integral support unit 13, and the SEM sample stage 15 passes through the central circular hole of the integral support unit 13 and can be used as a stage for a stretching device. The symmetrical positions on both sides of the overall support unit 13 are respectively provided with a three-dimensional coordinate translation platform and the connection substrate 11 of the overall support unit; each three-dimensional coordinate translation platform and the connection substrate 11 of the overall support unit are respectively installed by piezoelectric guide rails 1 translated in the X direction and translated in the Y direction. Coordinate three-dimensional coarse adjustment translation stage composed of piezoelectric guide rail 2 and Z direction translation piezoelectric guide rail 3. The upper end of the translational piezoelectric guide rail 3 in the Z direction is fixedly connected to the connecting arm 4 of the coarse adjustment platform, which can realize large-stroke loading; Three-dimensional precision displacement; the front end of the fine-tuning piezoelectric ceramic three-dimensional mobile platform 6 is connected to the sensor 8 through the sensor and the connecting sleeve 7 of the fine-tuning translation stage, and the front end of the sensor 8 is fixedly connected to the sample platform 9 .

The translational piezoelectric guide rail 1 in the X direction, the translational piezoelectric guide rail 2 in the Y direction, and the translational piezoelectric guide rail 3 in the Z direction are respectively composed of a one-dimensional piezoelectric motor and a guide rail. Each piezoelectric motor is connected to the drive system through the power supply and signal line. Under the action of the drive system, the platform driven by the guide rail moves coordinately along the X, Y, and Z directions (single step or continuous). The strokes in the Z direction and the Z direction are 12mm respectively, and the displacement resolution is 200nm.

The fine-tuning piezoelectric ceramic three-dimensional mobile platform 6 is connected to the drive system through power supply and signal line respectively, and can move finely in X, Y and Z directions respectively under the drive of the drive system, with a stroke of 6 μm and a displacement resolution of 1 nm.

In order to realize the connection of different types of sensors, the sensor 8 and the sample platform 9 are connected by threads and fixed pins. There are two types of sample platform 9, one is a plane symmetrical loading end or a V-shaped loading end, which is used for the measurement of tension and compression of film and silk samples, and the other is a probe-type loading end. , It should be tungsten wire or glass probe type, used for bending and vibration measurement of thin films or wires, micro-nano wires, columns, etc. The sample platform 9 can be configured with a corresponding pressing and fixing structure. The sample 10 and the sample platform 9 can be connected by any method such as gluing, electron beam irradiation welding and V-shaped bayonet according to the size and material of the sample. When the sensor 8 is not needed for displacement loading, the connecting sleeve 7 and the sample platform 9 between the sensor and the fine-tuning translation stage can be directly connected with the positioning pin through the sleeve.

Two M4 screw holes are also provided on the integral support unit 13 for connecting other manipulation or auxiliary equipment.

In the whole processing process of the device, high machining precision requirements are adopted, the left and right three-dimensional mobile platforms with symmetrical structure, and the left and right sample platforms are taken from the same block material for one-time overall processing and then divided to form, so as to ensure that the device The machining accuracy and the symmetry of the structure.

The working principle of this device is as follows: First, put the adjusted device on the sample platform of the SEM cavity (supporting electron microscope: FEI Quanta450FEG), and fix the whole device through positioning pin 16 and three M4-20 hexagon socket screws 12 The support unit 13 is connected to the base 14 of the SEM sample platform. In order to ensure the stable operation of the device, the connecting screws must be tightened. Then connect the power supply and signal lines of the device to the control unit and the drive system through the matching flange and the control unit outside the cavity. Regarding the structure and requirements of the flange used for communication and control of the SEM cavity, it can be manufactured or purchased according to the requirements of the electron microscope used. After all the electrical signals are connected, the door of the electron microscope can be closed, and the platform and device can be operated after vacuuming. Before mechanical testing, the device is first adjusted to the center of the field of view through the SEM three-dimensional platform, and the sample platform 9 and the sample 10 are observed by selecting an appropriate magnification. Regarding the adjustment of the sample platform and the installation of the sample in the detection device, there are two situations. For the sample with a characteristic scale of tens of microns or more, it can be carried out outside the SEM cavity with the aid of an optical microscope and a clamping device for the sample platform 9. Adjust, and then install the test piece by glue or V-shaped card slot; for the sample that cannot be distinguished by the optical microscope, first adjust the centering and straightness of the sample platforms 9 on both sides under the optical microscope through the sample adjustment jig, Then it is installed in the SEM cavity as described above. After vacuuming, adjust the straightness and centering of the sample platform 9 by SEM imaging again, and adjust it through the coarse and fine moving platforms of the device. The symmetrical sample platform 9 is adjusted to an appropriate distance, and then the micro-nano wire, micro-nano tube or column to be detected is installed on the sample platform 9 through auxiliary manipulation equipment, such as a micro-nano manipulator, and fixed by electron beam welding to complete Mounting of micro/nano specimens.

After the installation and adjustment of the system are completed, the driving device, sensor, and SEM image acquisition system can be started to detect the mechanical properties of micro-nano samples under microscopic conditions.

Uniaxial bidirectional micro-tensile measurement method for micro-nano-scale samples under scanning microscopic environment:

When the micro-nano-scale sample measurement device under the scanning microscope environment is applied to complete the uniaxial bidirectional micro-tensile measurement, it is first placed on the loading platform of the microscopic system (optical or SEM), and the microscopic system is used to measure Detect the surface structure and deformation images of the sample for observation and collection records. The specific measurement method is carried out as follows:

1) As mentioned above, according to the characteristic size of the sample, adjust the sample platform in the optical or SEM imaging environment to be centered, straight, and locked after the axis is consistent; adjust the sample platform to achieve a suitable initial loading distance; clamp and install Specimen, mount the specimen in an optical microscope or SEM cavity. When installing, ensure that the long axis of the sample coincides with the tensile axis of the stage. When installing a sample in a large-scale sample or in an optical microscopic environment, glue can be used to bond both ends of the sample to the symmetrical sample platform of the device for curing, and then put the device into the SEM environment chamber to complete subsequent operations and measurements ; In the case of micro-nano samples, put the device that has adjusted the centering and flat sample platform into the SEM environment chamber, observe by using SEM imaging, and use the auxiliary manipulation equipment to install the micro-nano sample to be detected on the sample platform and fixed by electron beam welding.

2) Adjust the detection platform position, magnification, imaging and image acquisition system of the scanning microscope system and make it in the detection state, and then drive the device to perform a uniaxial bidirectional micro-tension experiment on the micro-nano specimen, and scan it through the SEM at the same time Image recording sequence deformation images of the test area of the sample;

3) Perform digital image processing and micro-marker analysis on the obtained sequential deformation images to obtain the deformation evolution of the surface microstructure in the detection area during the uniaxial bidirectional stretching process; at the same time, combine the micro force sensor to obtain the corresponding The load information can be used to obtain the force-displacement or stress-strain curve of the test sample, as well as other mechanical performance parameters, such as Young's modulus, yield stress, and fracture limit, combined with the microstructure and microshape of the stretched film material. Analyze the knowledge and theory of appearance to find out the empirical results or laws of microstructure evolution and mechanical properties.

4) The image of the scanning microscope system corresponds to the surface and subsurface secondary electron emission intensity, which reveals the microstructure, micromorphology and other information of the tested sample, and displays it in the form of a grayscale image; when the sample surface is deformed or When the movement is small, these images expressed in grayscale can fully characterize the movement and deformation of the surface microstructure features of the material micro-region, so the problem of characteristic deformation and evolution of the sample surface microstructure is converted to the obtained grayscale image. Corresponding image processing issues, which can be obtained by digital image correlation (DIC) or micromarker tracking techniques.

Other measurement methods, such as compression, bending, vibration, etc., are similar to the above-mentioned measurement methods, only differing in the type of sample platform and driving mode.

Claims (7)

1. for the single-axis bidirectional micro mechanics measurement mechanism of scanning microscopy environment, it is characterized in that:

It is upper that integrated support unit (13) is arranged on SEM sample stage pedestal (14), in integrated support unit (13)Upper surface center circular hole is set, stretchable SEM sample stage (15) is installed in hole, SEM sample stage(15) bilateral symmetry position arranges respectively three-dimensional coordinate translation stage and integrated support unit connection substrate (11);

Each three-dimensional coordinate translation stage and integrated support unit connection substrate (11) are installed respectively by directions X translationThe coordinate of piezoelectricity guide rail (1), Y-direction translation piezoelectricity guide rail (2), Z direction translation piezoelectricity guide rail (3) compositionThe three-dimensional coarse adjustment translation stage of formula; The upper end of Z direction translation piezoelectricity guide rail (3) and coarse adjustment platform linking arm (4) are solidConnect, coarse adjustment platform linking arm (4) is by piezoelectricity sleeve pipe (5) and the three-dimensional mobile platform of fine tuning piezoelectric ceramics (6)Connect; The front end of the three-dimensional mobile platform of fine tuning piezoelectric ceramics (6) is by sensor and fine tuning translation stage adapter sleevePipe (7) is connected with sensor (8), and the front end of sensor (8) and sample platform (9) are affixed.

2. the single-axis bidirectional micro mechanics measurement mechanism for scanning microscopy environment according to claim 1,It is characterized in that: in passing through 3 between described integrated support unit (13) and SEM sample stage pedestal (14)Screw, two alignment pins (16) are fixedly connected with.

3. the single-axis bidirectional micro mechanics measurement mechanism for scanning microscopy environment according to claim 1,It is characterized in that: described directions X translation piezoelectricity guide rail (1), Y-direction translation piezoelectricity guide rail (2), Z directionTranslation piezoelectricity guide rail (3) is made up of an one dimension piezoelectric motor and a guide rail respectively.

4. the single-axis bidirectional micro mechanics measurement mechanism for scanning microscopy environment according to claim 1,It is characterized in that: described sample platform (9) is the symmetrical loading end of plane, V-type loading end or sonde-typeLoading end, and corresponding configuration is fixed structure.

Based on described in claim 1 device a measuring method, it is characterized in that, the method by asLower step is carried out:

(a) according to sample characteristics size Selection optics or SEM imaging circumstances adjust sample platform (9) centering,Straight, locking after axis is consistent; Adjust sample platform (9) and reach suitable initial loading spacing; At opticsIn microscope or SEM cavity, complete sample holder and installation, when installation, ensure long axis and the SEM sample of samplePlatform (15) stretching dead in line;

(b) adjust the detection platform position, multiplication factor, imaging and the image capturing system that scan microscopic systemAnd make it be in detected state, then drive unit carries out the micro-stretching experiment of single-axis bidirectional to test specimen, and simultaneously logicalCross the sequence deformation pattern that SEM scan image records sample surveyed area;

(c) the sequence deformation pattern of gained is carried out respectively to Digital Image Processing, micro-labeled analysis, obtain examinationSurveyed area surface micro-structure deformation evolution situation in single-axis bidirectional drawing process when sample stretches; Meanwhile knotClose Micro-force sensor and obtain corresponding load information, can obtain power-displacement or the stress-strain song of test samplesLine, and mechanical property parameter, comprising: Young's modulus, yield stress, break limit, and draw in conjunction with relevantStretch the microstructure of material, the knowledge and theory of micromorphology aspect is analyzed.

6. measuring method according to claim 5, is characterized in that, in described step (a), and sampleWhile sample being installed for large scale sample and under optical microphotograph environment, use glue that sample two ends are bonded in symmetricalSample platform (9) is upper solidifies, and then by whole measurement mechanism put into SEM environmental chamber complete subsequent operation andMeasure.

7. measuring method according to claim 5, is characterized in that, in described step (a), and sampleDuring for micro-nano sample, sample platform (9) adjusted centering and straight device are put into SEM environmental chamber,By SEM imaging, and utilize the micro-nano sample that assisted control equipment will detect to be attached to sample platform(9) upper, and be welded and fixed by electron beam deposition.