CN103558419B - A kind of scanning near-field optical monitor station - Google Patents

Abstract

The invention provides a scanning near-field optical detection platform, comprising: a body (22); the body includes mutually perpendicular XOY planes, YOZ planes, and ZOX planes; the XOY planes, YOZ planes, and ZOX planes enclose a storage space ; a rectangular worktable (18) for placing workpieces (17) in the storage space; the rectangular worktable includes a bottom surface and four sides vertically adjacent to each other; the four corners of the bottom surface of the rectangular workbench are provided with Four hydraulic drive units (21) fixed to the XOY surface of the body; two hydraulic drive units (11) fixed to the YOZ surface and the ZOX surface of the body are respectively provided on the two adjacent sides of the rectangular workbench ; The YOZ surface of the body is provided with a nozzle unit located above the workpiece for positioning the workpiece in the Z-axis direction. The elongation of the pillar in the invention is adjustable and measurable, so the displacement precision of the workbench is relatively high and the control is relatively simple; the effective travel of the workbench is relatively large.

Description

A scanning near-field optical detection platform

technical field

The invention relates to the field of optical mechanics, in particular to a scanning near-field optical detection device.

Background technique

With the increasing integration of modern optical systems, the scale of optical design structures is constantly decreasing. For sub-wavelength optical structures, the range of light fields that need to be detected is usually on the order of microns, and optical microscopes are no longer competent due to the limitation of the diffraction limit. A scanning near-field optical microscope based on optical probe technology provides a solution, which mainly includes a positioning module, a displacement module and a light field receiving and detecting module. Its main working principle is: the optical fiber probe is used to detect the coupled light field, which is fixed on the displacement device, and the optical probe is scanned within a certain range near the sample surface by controlling the positioning and displacement device. After computer processing, the light field distribution can be obtained.

The three-dimensional scanning mobile worktable is one of the key components in the scanning near-field light microscopy detection device. It requires nanometer-level motion accuracy (generally tens of nanometers), and the linearity, orthogonality, and Repeatability and stability have extremely high requirements. Among the various types of scanning near-field light microscopy detection devices, most of them are designed with two systems of coarse motion and micro motion. The micro motion system is various types of multi-dimensional elastic hinged worktables, and the drive adopts transistors. The more common model of the parallelogram elastic hinge mechanism is shown in Figure 1. The schematic diagram of the parallelogram flexible hinge mechanism: the rigid pillar 3 is connected with the fixed plate 4 and the moving plate 1 through the flexible hinge 2 to form a parallelogram symmetrical structure, because the flexible hinge 2 has A necked part whose cross-sectional area is much smaller than other parts, so it can be considered that only the flexible hinge 2 is deformed during the working process, while other parts are regarded as rigid bodies (actually, the deformation is extremely small and can be ignored) . During the working process, when the force F is required to act on the symmetrical position of the center of one end of the moving plate 1 along the direction parallel to the moving plate 1, the moving plate 1 can move one-dimensionally relative to the fixed plate 4 along the x-axis direction at this time. , only the constricted part of the flexible hinge 2 can produce a small corner. In actual work, there are inevitably errors in the position and direction of the point of action of the force F, and there are inevitably errors in the manufacture of the flexible hinge mechanism. There is mutual coupling between them, and the sports board 1 cannot move strictly in the x direction.

The existing 3D scanning mobile workbench generally has multiple (usually 3) parallelogram flexible hinges arranged orthogonally to each other, and the components are connected in a solid state. Due to the complex coupling of the movement and force of each dimension, Certain errors inevitably exist in the movement of the three-dimensional worktable, and this error is difficult to eliminate. The micro-drive of the existing three-dimensional scanning mobile worktable generally adopts piezoelectric crystal driver, which has high driving precision, but the effective stroke is small, so it needs to be equipped with a coarse motion device, and the mechanism is relatively complicated.

In view of this, it is necessary to provide a new scanning near-field optical detection platform to solve the above technical problems.

Contents of the invention

In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a scanning near-field optical detection platform, which has the following advantages compared with existing similar equipment: the elongation of the pillar is adjustable and measurable, so the workbench The displacement accuracy is high and the control is relatively simple; the effective stroke of the table movement is relatively large.

In order to achieve the above purpose and other related purposes, the present invention provides a scanning near-field optical detection platform, the scanning near-field optical detection platform at least includes: a body; the body includes mutually perpendicular XOY planes, YOZ planes and ZOX planes; The XOY surface, the YOZ surface and the ZOX surface enclose a storage space; the rectangular workbench for placing workpieces in the storage space; the rectangular workbench includes a bottom surface parallel to XOY and perpendicular to the bottom surface and The four sides vertically adjacent to each other; the four corners of the bottom surface of the rectangular workbench are provided with four hydraulic drive units fixed to the XOY surface of the body; the two adjacent sides of the rectangular workbench are respectively provided with Two hydraulic drive units (11) fixed on the YOZ surface and the ZOX surface of the main body; the YOZ surface of the main body is provided with a nozzle unit located above the workpiece for positioning the workpiece in the Z-axis direction.

Preferably, the hydraulic drive unit (21) includes a pipe body provided with a cavity, an upper end cover and a lower end cover for sealing the cavity, and a screw on the upper end cover and the lower end cover for connecting the body. A flexible hinge, an oil inlet channel located in the lower end cover and communicated with the cavity, an oil inlet pipe joint communicated with the oil inlet channel, and resistance strain gauges evenly distributed outside the tube.

Preferably, the nozzle unit includes a nozzle bracket fixed to the body, a nozzle provided at one end of the nozzle bracket and provided with an air inlet hole and an air outlet hole; A nut; the lower end of the nozzle is covered with a nut; a compression spring is arranged between the nut and the adjusting nut.

Preferably, the nozzle bracket fixed to the body is fixed with screws.

Preferably, each hydraulic drive unit is fixed to the body by two screws.

Preferably, the upper end cover and the lower end cover are welded to seal the cavity.

Compared with the existing piezoelectric crystal driver, the hydraulic drive unit proposed by the present invention, which can detect the driving displacement value in real time, uses a liquid with a certain pressure to be filled into the sealed cylindrical tubular cavity so that the cylindrical tubular cavity generates a corresponding axis. To achieve micro-displacement drive by elongation, use the resistance strain gauge attached to the outer wall of the cylindrical tubular cavity to measure the axial elongation generated by the cylindrical tubular cavity in real time and feedback control the hydraulic pressure supplied to the hydraulic drive to realize the output displacement. Therefore, the hydraulically driven scanning near-field light detection platform proposed by the present invention has the advantages of large driving stroke, stable driving process and high driving precision, and overcomes the small driving stroke, poor stability and error of the piezoelectric crystal. Correction of defects such as poor ability.

Secondly, the present invention is provided with flexible hinges at the upper and lower ends of the hydraulic drive unit, and uses them as pillars to support the workbench, and integrates the drive and support in the flexible hinge mechanism to form a flexible hinge with adjustable support length. The hinge mechanism is used to adjust the position error of the workbench, which not only simplifies the structure of the flexible hinge mechanism, but also reduces the requirements for manufacturing accuracy.

In addition, in the hydraulically driven scanning near-field light detection table proposed in the present invention, the compressed air flow rate flowing through the nozzle is used to detect the gap between the nozzle and the workpiece, and the positioning measurement of the workpiece surface in the Z-axis direction is realized. This measurement method has the advantages of simple structure, no damage to the workpiece surface, good stability and strong anti-interference ability.

Description of drawings

Fig. 1 shows a schematic diagram of an existing parallelogram flexible hinge mechanism.

Fig. 2 is a front view of the hydraulically driven scanning near-field light detection platform proposed by the present invention.

Fig. 3 is a view from direction A in Fig. 2 .

Fig. 4 is a top view of a scanning near-field light detection platform based on hydraulic drive proposed by the present invention.

Fig. 5 is a schematic diagram of the mechanism of the hydraulic drive unit of the present invention.

Fig. 6 is a B-B sectional view in Fig. 5 .

Component designation description

Inlet hole 11 Nozzle 12

Adjusting nut 13 Compression spring 14

Nut 15 Nozzle air outlet 16

Workpiece 17 Workbench 18

Screws 19, 20, 23 Hydraulic drive unit 21

Body 22 Nozzle holder 24

Flexible hinge 31 cavity 32

Oil inlet channel 33 lower end cover 34

Screw connection through hole 35 oil inlet pipe joint 36

Resistance strain gauge 37 Cylindrical tube 38

Upper end cap 39

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to Figure 1 to Figure 6. It should be noted that the diagrams provided in this embodiment are only schematically illustrating the basic idea of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of the components in actual implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated.

The present invention provides a scanning near-field optical detection platform, the scanning near-field optical detection platform at least includes: a body 22; the body includes mutually perpendicular XOY planes, YOZ planes and ZOX planes; the XOY planes, YOZ planes and The ZOX surface surrounds a receiving space; The rectangular workbench 18 that is used to place the workpiece 17 in the receiving space is accommodated; the rectangular workbench includes a bottom surface and four sides perpendicular to the bottom surface; the rectangular workbench Four hydraulic drive units 21 fixed to the XOY surface of the body are provided at the four corners of the bottom surface; two hydraulic drive units 11 fixed to the YOZ surface and the ZOX surface of the body are respectively provided on the two adjacent sides of the rectangular workbench ; The YOZ surface of the body is provided with a nozzle unit located above the workpiece for positioning the workpiece in the Z-axis direction.

The hydraulic drive unit 21 includes a pipe body 38 provided with a cavity 32, an upper end cover 39 and a lower end cover 34 for sealing the cavity, and a flexible flexible tube on the upper end cover and the lower end cover for connecting the body. The hinge 31 , the oil inlet channel 33 located in the lower end cover and communicated with the cavity, the oil inlet pipe joint 36 communicated with the oil inlet channel, and the resistance strain gauges 37 evenly distributed outside the tube. In this embodiment, preferably, the resistance strain gauge 37 is pasted around the outside of the tube.

The nozzle unit includes a nozzle bracket 24 fixed to the body 22, a nozzle 12 arranged at one end of the nozzle bracket and provided with an air inlet 11 and an air outlet 16; the nozzle and the nozzle bracket are sleeved There is an adjusting nut 13; the lower end of the nozzle is covered with a nut 15; a compression spring 14 is arranged between the nut and the adjusting nut.

The nozzle bracket fixed with the body is fixed with screws 23. Each hydraulic drive unit is fixed to the body by two screws 20 . The upper end cover and the lower end cover are welded to seal the cavity.

Specifically, please refer to FIG. 2 , FIG. 3 and FIG. 4 which show a scanning near-field light detection platform based on hydraulic drive. Set the three-dimensional Cartesian coordinate system O-X-Y-Z as shown in the figure, the workbench 18 with a rectangular hexahedron structure is connected to the body 22 through 8 hydraulic drive units 21, wherein: the body includes mutually perpendicular XOY planes, YOZ planes and ZOX planes; The XOY surface, YOZ surface and ZOX surface enclose a storage space; the bottom of the body is connected to the body 22 with 4 hydraulic drive units 21 parallel to the Z axis, and two adjacent sides are connected with the X axis and Y axis respectively. The parallel hydraulic drive unit 21 is connected with the main body, the screw 19 connects the upper end cover 39 of the hydraulic drive unit 21 with the workbench 18, the screw 20 connects the lower end cover 34 of the hydraulic drive unit 21 with the main body 22; the nozzle holder 24 is connected with the main body 22 through the screw 23 Connected; the adjusting nut 13 is installed in the threaded hole provided along the Z-axis direction at the end of the nozzle bracket, and the nozzle 12 is installed in the inner hole of the adjusting nut 13, and the inner space of the nozzle 12 and the adjusting nut 13 is a sliding fit The lower end of the nozzle 12 is equipped with a nut 15, and the nut 15 compresses the compression spring 14 installed on the nozzle 12 on the lower end surface of the adjusting nut 13. When the end surface of the nozzle air outlet 16 is subjected to a large axial force, the nozzle 12 can move upwards to avoid violent collision between the nozzle and the surface of the workpiece; supply constant pressure compressed air to the air inlet 11 of the nozzle 12, and the compressed air passes through the outlet hole 16 of the nozzle and between the nozzle and the workpiece 17 placed on the workbench 18 There is a one-to-one relationship between the gas flow flowing through the nozzle 12 and the gap between the nozzle and the workpiece, so the gap between the nozzle and the workpiece can be obtained by measuring the gas flow flowing into the nozzle 12, so as to realize The positioning of the workpiece 17 in the Z-axis direction.

When working, first supply liquid with constant pressure to each hydraulic drive unit, and when the worktable 18 needs to move along a certain coordinate axis direction, it can be realized by increasing or decreasing the supply liquid pressure of the hydraulic drive unit in this direction; Since each hydraulic drive unit can detect the actual displacement in real time, and control the liquid pressure at the supply end according to the actual displacement of each hydraulic drive unit, and correct the error of the actual displacement in real time, it can achieve higher displacement accuracy ;

FIG. 5 and FIG. 6 are schematic diagrams of the detailed structure of the hydraulic drive unit 21 described in FIG. 2 to FIG. 4 . In the hydraulic drive unit shown in Figures 5 and 6, the upper and lower ends of the cylindrical tube 38 are respectively connected to the upper end cover 39 and the lower end cover 34, and the cylindrical tube 38, the upper end cover 39 and the lower end cover 34 are all welded. Sealed connection to form an airtight cavity 32; a flexible hinge 31 and four screw connection through holes 35 for screw connection are respectively designed on the upper end cover 39 and the lower end cover 34; 4 identical resistance strain gauges 37; the lower end cover 34 is provided with an oil inlet pipe joint 36, and the lower end cover 34 and the oil inlet pipe joint 36 are sealed and installed, and the inner hole channel in the oil inlet pipe joint 36 is connected to the lower end cover 34 The oil inlet passage 33 in is connected.

When working, the pressure oil is connected to the oil inlet pipe joint 36, and the pressure oil can enter the cavity 32, and the cylindrical tube 38 is slightly elongated under the action of the pressure oil, and changing the oil supply pressure can make the cylindrical tube 38 produce the required Elongation: The resistance strain gauge 37 can measure the elongation of the cylindrical tube 38 in real time and feed back the signal to the oil supply system. When the error of the elongation of the cylindrical tube 38 exceeds the allowable value, the oil supply system adjusts the supply according to the feedback signal The oil pressure makes the elongation error of the cylindrical tube 38 get back within the allowable value range. The elongation (displacement range) and accuracy of the cylindrical tube 38 are related to the tube wall thickness, tube length, and liquid pressure control accuracy. The required displacement accuracy and range can be obtained by properly selecting each parameter. The hydraulic drive unit has the function of measuring the driving displacement in real time and is provided with a feedback mechanism, so the driving precision is high.

Specifically, a scanning near-field light detection station for detecting the intensity of the light field emitted by the surface of the sub-wavelength structure on the SOI chip is required to be able to produce light in the X, Y, and Z directions with an accuracy of the order of 10 nanometers and a maximum stroke of 2 mm. Displacement movement, in addition, the accurate value between the SOI sheet surface and a reference plane (fiber probe end face or related reference plane) can be measured in the Z direction, the measurement accuracy is 0.1 microns, the range is 1 mm, and the designed scan The structure of the near-field light detection table is shown in Figure 2, Figure 3, and Figure 4, and the hydraulic drive unit is shown in Figure 5 and Figure 6.

Compared with the existing piezoelectric crystal driver, the hydraulic drive unit proposed by the present invention, which can detect the driving displacement value in real time, uses a liquid with a certain pressure to be filled into the sealed cylindrical tubular cavity so that the cylindrical tubular cavity generates a corresponding axis. To achieve micro-displacement drive by elongation, use the resistance strain gauge attached to the outer wall of the cylindrical tubular cavity to measure the axial elongation generated by the cylindrical tubular cavity in real time and feedback control the hydraulic pressure supplied to the hydraulic drive to realize the output displacement. Therefore, the hydraulically driven scanning near-field light detection platform proposed by the present invention has the advantages of large driving stroke, stable driving process and high driving precision, and overcomes the small driving stroke, poor stability and error of the piezoelectric crystal. Correction of defects such as poor ability.

Secondly, the present invention is provided with flexible hinges at the upper and lower ends of the hydraulic drive unit, and uses them as pillars to support the workbench, and integrates the drive and support in the flexible hinge mechanism to form a flexible hinge with adjustable support length. The hinge mechanism is used to adjust the position error of the workbench, which not only simplifies the structure of the flexible hinge mechanism, but also reduces the requirements for manufacturing accuracy.

In addition, in the hydraulically driven scanning near-field light detection table proposed in the present invention, the compressed air flow rate flowing through the nozzle is used to detect the gap between the nozzle and the workpiece, and the positioning measurement of the workpiece surface in the Z-axis direction is realized. This measurement method has the advantages of simple structure, no damage to the workpiece surface, good stability and strong anti-interference ability.

To sum up, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (5)

1. a scanning near-field optical monitor station, is characterized in that, described scanning near-field optical monitor station at least comprises:

Body (22); Described body comprises orthogonal XOY face, YOZ face and ZOX face; Described XOY face, YOZ face and ZOX face surround a receiving space;

Be contained in the rectangular table (18) for place work piece (17) in described receiving space; Described rectangular table comprises the bottom surface parallel with XOY and perpendicular to described bottom surface and mutual vertical four adjacent sides;

The corner, bottom surface of described rectangular table is provided with four hydraulic drive unit (21) fixing with described body XOY face; Two sides that described rectangular table is adjacent are respectively equipped with two hydraulic drive unit of fixing with described body YOZ face and ZOX face;

Described body YOZ face is provided with the nozzle unit for realizing described workpiece location be in the Z-axis direction positioned at above described workpiece;

Described hydraulic drive unit (21) comprises the body (38) being provided with cavity (32), seal upper end cover (39) and the bottom end cover (34) of described cavity, be positioned at described upper end cover with on described bottom end cover for being connected the flexible hinge (31) of described body, be positioned at the oil inlet passage (33) that described bottom end cover is communicated with described cavity, the inlet connector (36) be communicated with described oil inlet passage and the resistance strain gage (37) be evenly distributed on outside body.

2. scanning near-field optical monitor station according to claim 1, it is characterized in that, the nozzle (12) that described nozzle unit comprises the nozzle holder (24) fixing with described body (22), is arranged at described nozzle holder one end, is provided with air admission hole (11) and venthole (16); Setting nut (13) is arranged with between described nozzle and described nozzle holder; Described nozzle lower end is arranged with nut (15); Compress Spring (14) is provided with between described nut and described setting nut.

3. scanning near-field optical monitor station according to claim 2, is characterized in that, the nozzle holder fixing with described body adopts screw (23) to fix.

4. scanning near-field optical monitor station according to claim 1, is characterized in that, described each hydraulic drive unit and described body are fixed by two screws (20).

5. scanning near-field optical monitor station according to claim 1, is characterized in that, described upper end cover and bottom end cover adopt the mode of welding to seal described cavity.