CN105127599A - Method and system for exposing elliptic motion during femtosecond laser machining of motion workpiece - Google Patents

Abstract

The invention relates to a method and a system for exposing elliptic motion during femtosecond laser machining of a motion workpiece, and belongs to the technical field of femtosecond laser machining. According to the method, an elliptic motion workbench is mounted on a motion platform; driven by the three-dimensional elliptic motion workbench, a to-be-machined workpiece performs high-frequency three-dimensional elliptic motion in a translational manner, relative to the motion platform for feeding in the X and Y directions; through frequency and amplitude adjustment of the elliptic motion, the projectional components in the X and Y directions of the instantaneous velocity of an expected exposure position p in the to-be-machined workpiece have the same magnitude but different directions with the feeding velocities in the X and Y directions of the motion platform at the upper vertex or the lower vertex of an ellipse, so that a laser beam can quasi-statically reside relative to the motion workpiece under the condition of sufficient luminous flux; through amplitude change of the elliptic motion, the distance between two adjacent exposure positions can be adjusted. The method and the system are easy to implement during femtosecond laser machining, and an expected exposure position in a workpiece can be efficiently exposed in a rapid workpiece feeding process.

Description

Elliptic motion exposure method and system in the processing of Moving Workpieces femtosecond laser

Technical field

The invention belongs to femtosecond laser processing technique field, particularly relate to elliptic motion exposure method and system in the processing of a kind of Moving Workpieces femtosecond laser.

Background technology

Femtosecond laser process technology relates generally to and utilizes femtosecond laser beam to carry out the processing technologys such as surface of the work ablation, body implode, refraction index changing, two photon polymerizations, not only can be used for preparing three-dimensional nano-micro structure function surface device, also can be used for changing material internal character, and three-dimensional nano-micro structure function element in body can be prepared, receive extensive concern at many important engineering fields.No matter utilize that femtosecond laser beam is removed material, modification or be shaped, femtosecond laser beam acts on workpiece all must have sufficient luminous flux.In order to obtain large-area three-dimensional nano-micro structure function element, femtosecond laser beam must do scanning motion relative to workpiece, or workpiece does feed motion relative to femtosecond laser beam.

Existing scanning or feeding are implemented, and relate generally to two kinds of fundamental types: first workpiece is motionless, by one dimension or 2-D vibration mirror deflection femtosecond laser beam, make femtosecond laser beam do scanning motion relative to workpiece; It two is that laser beam is motionless, and the sports platform of clamping workpiece does translation feed motion relative to femtosecond laser beam.No matter be the first scan method or the second feeding method, interaction between femtosecond laser beam and workpiece relates generally to two kinds of exposure technique schemes: one, the intercropping point position of femtosecond laser beam and workpiece exposes (Pinpointexposure), this requires that laser beam must be in geo-stationary at the exposure position expected relative to workpiece, but the sports platform of the laser beam or translation feeding fast of doing deflection at a high speed stops rapidly and stablize being very difficult at the volley; They are two years old, the intercropping continuous exposure (Continuousexposure) of laser beam and workpiece, but in order to make workpiece material obtain enough luminous fluxes, femtosecond laser beam must be limited in particular range relative to the sweep speed of workpiece to be added, which has limited the raising of working (machining) efficiency.

Summary of the invention

This provides elliptic motion exposure method and system in the processing of a kind of Moving Workpieces femtosecond laser, anxious problem of stopping is difficult to solve the sports platform that loads femtosecond laser beam or workpiece due to motional inertia, and the problem avoiding femtosecond laser beam scan velocity or sports platform feed speed in continuous exposure to be limited to luminous flux being difficult to improve, thus the requirement of meeting requirements on three-dimensional nano-micro structure highly-efficient processing better.

The technical scheme that the present invention takes comprises the following steps:

(1) by clamping workpiece to be added on an elliptic motion workbench, elliptic motion workbench is arranged on can along on the sports platform of X and Y-direction feeding, under the driving of elliptic motion workbench, workpiece to be added does two-dimensional elliptic motion or three-dimensional elliptical motion with translational movement relative to sports platform, the sports platform of elliptic motion workbench is installed, by forming along X to the sports platform of feeding with along the sports platform of Y-direction feeding, the translation feeding of Long Distances can be carried out to realize the scanning motion of workpiece relative to femtosecond laser beam along X-axis and Y-axis in XOY face, femtosecond laser beam need not carry out oscillatory scanning, sports platform and sports platform are that air supporting supports and adopts linear electric motors to carry out the kinematic axis of Direct driver respectively, each axle all has submicron order kinematic accuracy and Long Distances, focusing objective len is arranged on Z axis sports platform, Z axis sports platform along the micromotion of Z axis for realizing laser beam foucing in workpiece to be added along the feeding in Z-direction, laser beam is sent by femto-second laser, after attenuator, optical shutter, beam expanding lens, speculum one, diaphragm, speculum two, speculum three, beam splitter, focusing objective len, act on workpiece to be added along Z-direction, the break-make of laser beam is controlled by optical shutter, process realizes online observation by digital camera, convex lens, beam splitter, and illumination light is sent by lighting source, through speculum reflection, is radiated on workpiece to be added,

(2) the elliptic motion workbench described in, the objective table of three piezoelectric actuating elements Direct driver flexible support is adopted to do cycle movement along X, Y and Z-direction respectively, by controlling the phase difference between adjacent two directions of motion, with the elliptical trajectory making objective table form two dimension respectively on vertical plane XOZ and YOZ, horizontal plane XOY forms reciprocal straight-line trajectory; The input signal of three piezoelectric actuating elements is:

$\left\{\begin{array}{c}{u}_x\left(t\right)=V_{x}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_x)\\ u_y\left(t\right)=V_{y}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_y)\\ u_z\left(t\right)=V_{z}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_z)\end{array}\right.---\left(1\right)$

In formula, V _x, V _y, V _zbe respectively X, Y, Z-direction three piezoelectric actuating elements drive singal u _x(t), u _y(t), u _zthe amplitude of (t); for being respectively the initial phase of X, Y, Z-direction drive singal; F is the frequency of drive singal.Under the driving of three-dimensional elliptical motion workbench, workpiece desired exposure position p displacement to be added can be expressed as:

In formula, a _x, a _yand a _zthe amplitude in X-axis, Y-axis, Z-direction of desired exposure position p in workpiece to be added respectively; with the initial phase that desired exposure position p vibrates at X, Y and Z-direction respectively; F is the motion frequency of three-dimensional elliptical motion workbench;

In order to make desired exposure position p in workpiece form straight path on coordinate plane XOY, and on coordinate plane XOZ and YOZ, form elliptical orbit respectively, between adjacent motion, phase difference must meet:

In formula, n ₁, n ₂, n ₃be all integer. for with phase difference, for with phase difference, for with phase difference.Particularly when meeting:

Time, in workpiece to be added, desired exposure position p will form the elliptical orbit of standard respectively on coordinate plane XOZ and YOZ, and namely two oval major axis all will be parallel to reference axis OX and OY respectively;

(3) in order to make on workpiece to be added desired exposure position p be zero relative to the instantaneous velocity of laser beam on horizontal plane XOY, following condition must be met:

$\left\{\begin{array}{c}{v}_{px}=-v_{fx}\\ v_{py}=-v_{fy}\end{array}\right.---\left(5\right)$

In formula, v _pxand v _pybe respectively on workpiece desired exposure position p relative to the instantaneous velocity v of sports platform 12 _pat the component of X and Y-direction; v _fxand v _fysports platform respectively along the feed speed of X and Y-direction; On workpiece, namely the instantaneous velocity direction of desired exposure position p is the linear reciprocating motion direction on the coordinate plane XOY of level, synthesis feed speed v _pwith the synthesis feed speed v of sports platform 12 _fequal and opposite in direction, direction are contrary;

Can be obtained by formula (2), in workpiece, three velocity components of desired exposure position p are as follows:

The horizontal velocity v on summit under ellipse can be obtained by formula (6) _pbe respectively at the absolute value of X, Y-direction component:

$\left\{\begin{array}{c}{v}_{px}=2{\mathrm{\πa}}_{x}f\\ v_{py}=2{\mathrm{\πa}}_{y}f\end{array}\right.---\left(7\right)$

Therefore by changing the amplitude a of three-dimensional elliptical motion workbench _xand a _yand the motion frequency f of three-dimensional elliptical motion workbench is to regulate v _pxand v _py, thus coupling workbench in x and y direction feed speed v _fxand v _fy;

Now, shutter break-make once, completes single exposure;

(4) for realizing the Continuous maching of laser beam to workpiece, when each elliptical trajectory arrives lower summit, exposure must be completed once, i.e. the break-make frequency f of optical shutter _sthe frequency f that elliptic motion done by workpiece should be equaled, synchronous with the elliptic motion of the break-make with workpiece that make femtosecond laser beam, that is femtosecond laser beam only acts on workpiece in summit and local neighborhood under elliptic motion done by workpiece, next cycle exposure position and last cycle are exposed on the distance d of X, Y-direction _x, d _yfor:

$\left\{\begin{array}{c}{d}_x=v_{fx}T=\frac{v_{fx}}{f}\\ d_y=v_{fy}T=\frac{v_{fy}}{f}\end{array}\right.---\left(8\right)$

Can be obtained by formula (5), formula (7), formula (8) simultaneous:

$\{\begin{array}{c}{a}_x=\frac{d_x}{2\mathrm{\π}}\\ a_y=\frac{d_y}{2\mathrm{\π}}\end{array}---\left(9\right)$

Three-dimensional elliptical motion workbench is at the amplitude a of X, Y-direction _x, a _yby the distance d of adjacent periods exposure position in X, Y-direction _x, d _ydetermine.When three-dimensional elliptical motion workbench is at the amplitude a of X, Y-direction _x, a _yafter determining, can be obtained by formula (5), (7):

$f=\frac{v_{fx}}{2{\mathrm{\πa}}_x}=\frac{v_{fy}}{2{\mathrm{\πa}}_y}---\left(10\right)$

The motion frequency f of three-dimensional elliptical motion workbench is by the feed speed v of sports platform in X, Y-direction _fx, v _fydetermine, the feed speed of sports platform determines the process velocity of workpiece to be added, when sports platform speed promotes, improve the frequency of three-dimensional elliptical motion workbench, can the feed speed of matched motion platform, thus achieve and to do in the process of fast feed the position of desired exposure in workpiece at workpiece and efficiently expose.

The system that the present invention realizes elliptic motion exposure method in the processing of Moving Workpieces femtosecond laser is:

Femto-second laser, through attenuator, optical shutter, beam expanding lens, speculum one, diaphragm, speculum two, speculum three, beam splitter, focusing objective len order light connect, digital camera and convex lens are positioned at above beam splitter, moveable table position is in the below of focusing objective len, lighting source and speculum are positioned at below sports platform, and elliptic motion workbench is positioned at above sports platform.

The structure of described elliptic motion workbench is: side shield one is connected with base plate by screw three, screw four, side shield two is connected with base plate by screw five, screw six, and the stiff end one with the workbench of hinge arrangement is arranged on side shield one by screw seven, screw eight; Stiff end two is arranged on side shield two by screw nine, screw ten, X passes through pre-loading screw one with X to drive block apical grafting to piezoelectric stack one, Y-direction piezoelectric stack two is by pre-loading screw two and Y-direction drive block apical grafting, Z-direction block is fixed on X on drive block by hold-down screw one, hold-down screw two, Z-direction piezoelectric stack three is arranged on Z-direction block, by bottom pre-loading screw three and objective table apical grafting; X is consistent to piezoelectric stack one direction with X to displacement transducer, is arranged on X in piezoelectric stack one by one side through hole, is fixed by trip bolt three; Y-direction displacement transducer is consistent with Y-direction piezoelectric stack two direction, is arranged in Y-direction piezoelectric stack 21 side through hole, is fixed by trip bolt four; Z-direction displacement transducer is consistent with Z-direction piezoelectric stack three direction, is arranged on Z-direction block, in Z-direction piezoelectric stack three side, is fixed by trip bolt five;

The described workbench with hinge arrangement is by objective table, X is to drive block, Y-direction drive block, stiff end one, stiff end two is formed by connecting by the flexible hinge between them, described objective table is by flexible hinge one, flexible hinge two, flexible hinge three, flexible hinge four connects to drive block with X, X to drive block by compound hinges one, compound hinges two, compound hinges three, compound hinges four is connected with Y-direction drive block, compound hinges one and compound hinges two are symmetrical structure relative to main body Y-direction center, compound hinges three and compound hinges four are symmetrical structure relative to main body Y-direction center, compound hinges one is symmetrically distributed in X to drive block two ends with compound hinges two, compound hinges three with compound hinges four, be connected with Y-direction drive block, compound hinges five and compound hinges six are symmetrical structure relative to main body X to center, compound hinges seven and compound hinges eight are symmetrical structure relative to main body X to center, compound hinges five is symmetrically distributed in Y-direction drive block two ends with compound hinges six, compound hinges seven with compound hinges eight, and both sides are connected with stiff end one, stiff end two respectively,

Described compound hinges one, compound hinges two, compound hinges three or compound hinges four are joined end to end by four straight beam type hinges respectively and form.

By the ACTIVE CONTROL of the amplitude to piezoelectric stack one, piezoelectric stack two, piezoelectric stack three, frequency and phase place, realize workbench and do two-dimensional elliptic motion or three-dimensional elliptical motion in space.

Advantage of the present invention utilizes described method and system can expose relative in the fast feed of femtosecond laser beam, to the desired exposure position of Moving Workpieces at the sports platform of clamping workpiece, not only can solve the sports platform that loads femtosecond laser beam or workpiece due to motional inertia is difficult to anxious problem of stopping, also problem femtosecond laser beam scan velocity or sports platform feed speed in continuous exposure can being avoided to be limited to luminous flux be difficult to improve, thus the requirement of meeting requirements on three-dimensional nano-micro structure highly-efficient processing better.The present invention is easy to implement in femtosecond laser processing, can to do in the process of fast feed the position of desired exposure in workpiece efficiently expose at workpiece.

Accompanying drawing explanation

Fig. 1 is the structure chart of Moving Workpieces elliptic motion exposure system in femtosecond laser processing;

The X-Y that Fig. 2 is made up of to sports platform and Y-direction sports platform X is to sports platform structural representation;

Fig. 3 is three-dimensional elliptical track and the projection of three-dimensional elliptical track on XOZ, YOZ, XOY plane of the formation of three-dimensional elliptical motion workbench;

Fig. 4 is the schematic diagram that femtosecond laser beam carries out elliptic motion exposure in XOZ plane in workpiece motion s, the instantaneous resident exposure and work is fixed a point of the desired location of femtosecond laser beam on workpiece to be added, and elliptical trajectory is clockwise at plane X OZ;

Fig. 5 is the schematic diagram that femtosecond laser beam carries out elliptic motion exposure in YOZ plane in workpiece motion s, the instantaneous resident exposure and work is fixed a point of the desired location of femtosecond laser beam on workpiece to be added, and elliptical trajectory is clockwise at plane YOZ;

Fig. 6 be femtosecond laser beam in Moving Workpieces after desired exposure position p completes single exposure, arrive the perspective view of next desired exposure position p' in XOZ plane in next cycle;

Fig. 7 be femtosecond laser beam in Moving Workpieces after desired exposure position p completes single exposure, arrive the perspective view of next desired exposure position p' in XOZ plane in next cycle;

Fig. 8 is the structural representation of elliptic motion workbench of the present invention;

Fig. 9 looks up axonometric drawing after elliptic motion workbench of the present invention removes base plate;

Figure 10 is the axonometric drawing that elliptic motion workbench of the present invention has the workbench main body of flexible hinge;

Figure 11 is that in the present invention, elliptic motion workbench is symmetrically distributed in the schematic diagram of stressed both sides by the join end to end compound hinges that forms of even number straight beam type hinge;

Figure 12 is the top view that elliptic motion workbench of the present invention has the workbench main body of flexible hinge.

Detailed description of the invention

Comprise the following steps:

(1) by workpiece 14 clamping to be added on an elliptic motion workbench 2; Elliptic motion workbench 2 is arranged on can along on the sports platform 12 of X and Y-direction feeding; Under the driving of elliptic motion workbench 2, workpiece 14 to be added does two-dimensional elliptic motion or three-dimensional elliptical motion with translational movement relative to sports platform 12; The sports platform 12 of elliptic motion workbench 2 is installed, by can sports platform 1201 along from X to feeding and forming along the sports platform 1202 of Y-direction feeding, in XOY face, can carry out the translation feeding of Long Distances to realize the scanning motion of workpiece relative to femtosecond laser beam along X-axis and Y-axis, femtosecond laser beam need not carry out oscillatory scanning; Sports platform 1201 and sports platform 1202 are that air supporting supports and adopts linear electric motors to carry out the kinematic axis of Direct driver respectively, and each axle all has submicron order kinematic accuracy and Long Distances; Focusing objective len 15 is arranged on Z axis sports platform, Z axis sports platform along the micromotion of Z axis for realizing laser beam foucing in workpiece to be added along the feeding in Z-direction; Laser beam 13 is sent by femto-second laser 1, after attenuator 3, optical shutter 4, beam expanding lens 5, speculum 1, diaphragm 7, speculum 28, speculum 3 19, beam splitter 16, focusing objective len 15, acts on workpiece 14 to be added along Z-direction; The break-make of laser beam 13 is controlled by optical shutter 4; Process realizes online observation by digital camera 18, convex lens 17, beam splitter 16; Illumination light 11 is sent by lighting source 10, reflects through speculum 9, is radiated on workpiece 14 to be added.

(2) the elliptic motion workbench 2 described in, the objective table of three piezoelectric actuating elements Direct driver flexible support is adopted to do cycle movement along X, Y and Z-direction respectively, by controlling the phase difference between adjacent two directions of motion, with the elliptical trajectory making objective table form two dimension respectively on vertical plane XOZ and YOZ, horizontal plane XOY forms reciprocal straight-line trajectory; The input signal of three piezoelectric actuating elements is:

$\left\{\begin{array}{c}{u}_x\left(t\right)=V_{x}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_x)\\ u_y\left(t\right)=V_{y}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_y)\\ u_z\left(t\right)=V_{z}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_z)\end{array}\right.---\left(1\right)$

In formula, V _x, V _y, V _zbe respectively X, Y, Z-direction three piezoelectric actuating elements drive singal u _x(t), u _y(t), u _zthe amplitude of (t); for being respectively the initial phase of X, Y, Z-direction drive singal; F is the frequency of drive singal.Under the driving of three-dimensional elliptical motion workbench, workpiece desired exposure position p displacement to be added can be expressed as

In formula, a _x, a _yand a _zthe amplitude in X-axis, Y-axis, Z-direction of desired exposure position p in workpiece to be added respectively; with the initial phase that desired exposure position p vibrates at X, Y and Z-direction respectively; F is the motion frequency of three-dimensional elliptical motion workbench.

In order to make desired exposure position p in workpiece form straight path on coordinate plane XOY, and on coordinate plane XOZ and YOZ, form elliptical orbit respectively, between adjacent motion, phase difference must meet:

In formula, n ₁, n ₂, n ₃be all integer. for with phase difference, for with phase difference, for with phase difference.Particularly when meeting

Time, in workpiece to be added, desired exposure position p will form the elliptical orbit of standard respectively on coordinate plane XOZ and YOZ, and namely two oval major axis all will be parallel to reference axis OX and OY respectively.

(3) in order to make on workpiece to be added desired exposure position p be zero relative to the instantaneous velocity of laser beam on horizontal plane XOY, following condition must be met:

$\left\{\begin{array}{c}{v}_{px}=-v_{fx}\\ v_{py}=-v_{fy}\end{array}\right.---\left(5\right)$

In formula, v _pxand v _pybe respectively on workpiece desired exposure position p relative to the instantaneous velocity v of sports platform 12 _pat the component of X and Y-direction; v _fxand v _fysports platform respectively along the feed speed of X and Y-direction.It can thus be appreciated that namely the instantaneous velocity direction of desired exposure position p is the linear reciprocating motion direction on the coordinate plane XOY of level on workpiece, synthesis feed speed v _pwith the synthesis feed speed v of sports platform 12 _fequal and opposite in direction, direction are contrary.

Can be obtained by formula (2), in workpiece, three velocity components of desired exposure position p are as follows:

The horizontal velocity v on summit under ellipse can be obtained by formula (6) _pbe respectively at the absolute value of X, Y-direction component:

$\left\{\begin{array}{c}{v}_{px}=2{\mathrm{\πa}}_{x}f\\ v_{py}=2{\mathrm{\πa}}_{y}f\end{array}\right.---\left(7\right)$

Therefore by changing the amplitude a of three-dimensional elliptical motion workbench _xand a _yand the motion frequency f of three-dimensional elliptical motion workbench is to regulate v _pxand v _py, thus coupling workbench in x and y direction feed speed v _fxand v _fy;

Now, shutter break-make once, completes single exposure.

(4) for realizing the Continuous maching of laser beam to workpiece, when each elliptical trajectory arrives lower summit, exposure must be completed once, i.e. the break-make frequency f of optical shutter _sthe frequency f that elliptic motion done by workpiece should be equaled, synchronous with the elliptic motion of the break-make with workpiece that make femtosecond laser beam, that is femtosecond laser beam only acts on workpiece in summit and local neighborhood under elliptic motion done by workpiece.Next cycle exposure position and last cycle are exposed on the distance d of X, Y-direction _x, d _yfor:

$\left\{\begin{array}{c}{d}_x=v_{fx}T=\frac{v_{fx}}{f}\\ d_y=v_{fy}T=\frac{v_{fy}}{f}\end{array}\right.---\left(8\right)$

Can be obtained by formula (5), formula (7), formula (8) simultaneous:

$\{\begin{array}{c}{a}_x=\frac{d_x}{2\mathrm{\π}}\\ a_y=\frac{d_y}{2\mathrm{\π}}\end{array}---\left(9\right)$

Three-dimensional elliptical motion workbench is at the amplitude a of X, Y-direction _x, a _yby the distance d of adjacent periods exposure position in X, Y-direction _x, d _ydetermine.When three-dimensional elliptical motion workbench is at the amplitude a of X, Y-direction _x, a _yafter determining, can be obtained by formula (5), (7):

$f=\frac{v_{fx}}{2{\mathrm{\πa}}_x}=\frac{v_{fy}}{2{\mathrm{\πa}}_y}---\left(10\right)$

The motion frequency f of elliptic motion workbench is by the feed speed v of sports platform in X, Y-direction _fx, v _fydetermine.The feed speed of sports platform determines the process velocity of workpiece to be added.When sports platform speed promotes, improve the frequency of three-dimensional elliptical motion workbench, can the feed speed of matched motion platform, thus achieve and to do in the process of fast feed the position of desired exposure in workpiece at workpiece and efficiently expose.

The system that the present invention realizes elliptic motion exposure method in the processing of Moving Workpieces femtosecond laser is:

Femto-second laser 1, through attenuator 3, optical shutter 4, beam expanding lens 5, speculum 1, diaphragm 7, speculum 28, speculum 3 19, beam splitter 16, focusing objective len 15 order light connect, digital camera 18 and convex lens 17 are positioned at above beam splitter 16, sports platform 12 is positioned at the below of focusing objective len 15, lighting source 10 and speculum 9 are positioned at below sports platform 12, and elliptic motion workbench 2 is positioned at above sports platform 12.

The structure of described elliptic motion workbench 2 is: side shield 1 is connected with base plate 224 by screw 3 225, screw 4 227, side shield 2 214 is connected with base plate 224 by screw 5 212, screw 6 215, and the stiff end 1 with the workbench 209 of hinge arrangement is arranged on side shield 1 by screw 7 202, screw 8 208; Stiff end 2 20911 is arranged on side shield 2 214 by screw 9 211, screw 10, X passes through pre-loading screw 1 with X to drive block 20907 apical grafting to piezoelectric stack 1, Y-direction piezoelectric stack 2 206 is by pre-loading screw 2 205 and Y-direction drive block 20906 apical grafting, Z-direction block 219 is fixed on X on drive block 20907 by hold-down screw 1, hold-down screw 2 210, Z-direction piezoelectric stack 3 217 is arranged on Z-direction block 219, by bottom pre-loading screw 3 226 and objective table 20916 apical grafting; X is consistent to piezoelectric stack 1 direction with X to displacement transducer 220, is arranged on X in piezoelectric stack 1 side through hole, is fixed by trip bolt 3 221; Y-direction displacement transducer 203 is consistent with Y-direction piezoelectric stack 2 206 direction, is arranged in Y-direction piezoelectric stack 2 206 1 side through hole, is fixed by trip bolt 4 204; Z-direction displacement transducer 218 is consistent with Z-direction piezoelectric stack 3 217 direction, is arranged on Z-direction block 219, in Z-direction piezoelectric stack 3 217 side, is fixed by trip bolt 5 216;

The described workbench 209 with hinge arrangement is by objective table 20916, X is to drive block 20907, Y-direction drive block 20906, stiff end 1, stiff end 2 20911 is formed by connecting by the flexible hinge between them, described objective table 20916 is by flexible hinge 1, flexible hinge 2 20904, flexible hinge 3 20912, flexible hinge 4 20914 connects to drive block 20907 with X, X to drive block 20907 by compound hinges 1, compound hinges 2 20909, compound hinges 3 20915, compound hinges 4 20917 is connected with Y-direction drive block 20906, compound hinges 1 and compound hinges 2 20909 are symmetrical structure relative to main body Y-direction center, compound hinges 3 20915 and compound hinges 4 20917 are symmetrical structure relative to main body Y-direction center, compound hinges 1 and compound hinges 2 20909, compound hinges 3 20915 and compound hinges 4 20917 are symmetrically distributed in X to drive block two ends, be connected with Y-direction drive block, compound hinges 5 20901 and compound hinges 6 20905 are symmetrical structure relative to main body X to center, compound hinges 7 20910 and compound hinges 8 20913 are symmetrical structure relative to main body X to center, compound hinges 5 20901 and compound hinges 6 20905, compound hinges 7 20910 and compound hinges 8 20913 are symmetrically distributed in Y-direction drive block two ends, both sides respectively with stiff end 1, stiff end 2 20911 is connected,

Described compound hinges one, compound hinges 2 20909, compound hinges 3 20915 or compound hinges four are joined end to end by four straight beam type hinges respectively and form.

By the ACTIVE CONTROL of the amplitude to piezoelectric stack 1, piezoelectric stack 2 206, piezoelectric stack 3 217, frequency and phase place, realize workbench and do two-dimensional elliptic motion or three-dimensional elliptical motion in space.

Claims (5)

1. an elliptic motion exposure method in the processing of Moving Workpieces femtosecond laser, is characterized in that comprising the following steps:

(1) by clamping workpiece to be added on an elliptic motion workbench, elliptic motion workbench is arranged on can along on the sports platform of X and Y-direction feeding, under the driving of elliptic motion workbench, workpiece to be added does two-dimensional elliptic motion or three-dimensional elliptical motion with translational movement relative to sports platform, the sports platform of elliptic motion workbench is installed, by forming along X to the sports platform of feeding with along the sports platform of Y-direction feeding, the translation feeding of Long Distances can be carried out to realize the scanning motion of workpiece relative to femtosecond laser beam along X-axis and Y-axis in XOY face, femtosecond laser beam need not carry out oscillatory scanning, sports platform and sports platform are that air supporting supports and adopts linear electric motors to carry out the kinematic axis of Direct driver respectively, each axle all has submicron order kinematic accuracy and Long Distances, focusing objective len is arranged on Z axis sports platform, Z axis sports platform along the micromotion of Z axis for realizing laser beam foucing in workpiece to be added along the feeding in Z-direction, laser beam is sent by femto-second laser, after attenuator, optical shutter, beam expanding lens, speculum one, diaphragm, speculum two, speculum three, beam splitter, focusing objective len, act on workpiece to be added along Z-direction, the break-make of laser beam is controlled by optical shutter, process realizes online observation by digital camera, convex lens, beam splitter, and illumination light is sent by lighting source, through speculum reflection, is radiated on workpiece to be added,

(2) the elliptic motion workbench described in, the objective table of three piezoelectric actuating elements Direct driver flexible support is adopted to do cycle movement along X, Y and Z-direction respectively, by controlling the phase difference between adjacent two directions of motion, with the elliptical trajectory making objective table form two dimension respectively on vertical plane XOZ and YOZ, horizontal plane XOY forms reciprocal straight-line trajectory; The input signal of three piezoelectric actuating elements is:

$\left\{\begin{array}{c}{u}_x\left(t\right)=V_{x}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_x)\\ u_y\left(t\right)=V_{y}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_y)\\ u_z\left(t\right)=V_{z}cos(2\mathrm{\π}ft+{\mathrm{\φ}}_z)\end{array}\right.---\left(1\right)$

In formula, V _x, V _y, V _zbe respectively X, Y, Z-direction three piezoelectric actuating elements drive singal u _x(t), u _y(t), u _zthe amplitude of (t); φ _x, φ _y, φ _zfor being respectively the initial phase of X, Y, Z-direction drive singal; F is the frequency of drive singal.Under the driving of three-dimensional elliptical motion workbench, workpiece desired exposure position p displacement to be added can be expressed as:

In formula, a _x, a _yand a _zthe amplitude in X-axis, Y-axis, Z-direction of desired exposure position p in workpiece to be added respectively; with the initial phase that desired exposure position p vibrates at X, Y and Z-direction respectively; F is the motion frequency of three-dimensional elliptical motion workbench;

In order to make desired exposure position p in workpiece form straight path on coordinate plane XOY, and on coordinate plane XOZ and YOZ, form elliptical orbit respectively, between adjacent motion, phase difference must meet:

In formula, n ₁, n ₂, n ₃be all integer. for with phase difference, for with phase difference, for with phase difference.Particularly when meeting:

Time, in workpiece to be added, desired exposure position p will form the elliptical orbit of standard respectively on coordinate plane XOZ and YOZ, and namely two oval major axis all will be parallel to reference axis OX and OY respectively;

(3) in order to make on workpiece to be added desired exposure position p be zero relative to the instantaneous velocity of laser beam on horizontal plane XOY, following condition must be met:

$\left\{\begin{array}{c}{v}_{px}=-v_{fx}\\ v_{py}=-v_{fy}\end{array}\right.---\left(5\right)$

In formula, v _pxand v _pybe respectively on workpiece desired exposure position p relative to the instantaneous velocity v of sports platform 12 _pat the component of X and Y-direction; v _fxand v _fysports platform respectively along the feed speed of X and Y-direction; On workpiece, namely the instantaneous velocity direction of desired exposure position p is the linear reciprocating motion direction on the coordinate plane XOY of level, synthesis feed speed v _pwith the synthesis feed speed v of sports platform 12 _fequal and opposite in direction, direction are contrary;

Can be obtained by formula (2), in workpiece, three velocity components of desired exposure position p are as follows:

The horizontal velocity v on summit under ellipse can be obtained by formula (6) _pbe respectively at the absolute value of X, Y-direction component:

$\left\{\begin{array}{c}{v}_{px}=2{\mathrm{\πa}}_{x}f\\ v_{py}=2{\mathrm{\πa}}_{y}f\end{array}\right.---\left(7\right)$

Therefore by changing the amplitude a of three-dimensional elliptical motion workbench _xand a _yand the motion frequency f of three-dimensional elliptical motion workbench is to regulate v _pxand v _py, thus coupling workbench in x and y direction feed speed v _fxand v _fy;

Now, shutter break-make once, completes single exposure;

(4) for realizing the Continuous maching of laser beam to workpiece, when each elliptical trajectory arrives lower summit, exposure must be completed once, i.e. the break-make frequency f of optical shutter _sthe frequency f that elliptic motion done by workpiece should be equaled, synchronous with the elliptic motion of the break-make with workpiece that make femtosecond laser beam, that is femtosecond laser beam only acts on workpiece in summit and local neighborhood under elliptic motion done by workpiece, next cycle exposure position and last cycle are exposed on the distance d of X, Y-direction _x, d _yfor:

$\left\{\begin{array}{c}{d}_x=v_{fx}T=\frac{v_{fx}}{f}\\ d_y=v_{fy}T=\frac{v_{fy}}{f}\end{array}\right.---\left(8\right)$

Can be obtained by formula (5), formula (7), formula (8) simultaneous:

$\left\{\begin{array}{c}{a}_x=\frac{d_x}{2\mathrm{\π}}\\ a_y=\frac{d_y}{2\mathrm{\π}}\end{array}\right.---\left(9\right)$

Three-dimensional elliptical motion workbench is at the amplitude a of X, Y-direction _x, a _yby the distance d of adjacent periods exposure position in X, Y-direction _x, d _ydetermine.When three-dimensional elliptical motion workbench is at the amplitude a of X, Y-direction _x, a _yafter determining, can be obtained by formula (5), (7):

$f=\frac{v_{fx}}{2{\mathrm{\πa}}_x}=\frac{v_{fy}}{2{\mathrm{\πa}}_y}---\left(10\right)$

The motion frequency f of three-dimensional elliptical motion workbench is by the feed speed v of sports platform in X, Y-direction _fx, v _fydetermine, the feed speed of sports platform determines the process velocity of workpiece to be added, when sports platform speed promotes, improve the frequency of three-dimensional elliptical motion workbench, can the feed speed of matched motion platform, thus achieve and to do in the process of fast feed the position of desired exposure in workpiece at workpiece and efficiently expose.

2. the system of elliptic motion exposure in a Moving Workpieces femtosecond laser processing, femto-second laser, through attenuator, optical shutter, beam expanding lens, speculum one, diaphragm, speculum two, speculum three, beam splitter, focusing objective len order light connect, digital camera and convex lens are positioned at above beam splitter, moveable table position is in the below of focusing objective len, lighting source and speculum are positioned at below sports platform, it is characterized in that: elliptic motion workbench is positioned at above sports platform.

3. the system of elliptic motion exposure in a kind of Moving Workpieces femtosecond laser processing according to claim 2, it is characterized in that: the structure of described elliptic motion workbench is: side shield one is connected with base plate by screw three, screw four, side shield two is connected with base plate by screw five, screw six, and the stiff end one with the workbench of hinge arrangement is arranged on side shield one by screw seven, screw eight; Stiff end two is arranged on side shield two by screw nine, screw ten, X passes through pre-loading screw one with X to drive block apical grafting to piezoelectric stack one, Y-direction piezoelectric stack two is by pre-loading screw two and Y-direction drive block apical grafting, Z-direction block is fixed on X on drive block by hold-down screw one, hold-down screw two, Z-direction piezoelectric stack three is arranged on Z-direction block, by bottom pre-loading screw three and objective table apical grafting; X is consistent to piezoelectric stack one direction with X to displacement transducer, is arranged on X in piezoelectric stack one by one side through hole, is fixed by trip bolt three; Y-direction displacement transducer is consistent with Y-direction piezoelectric stack two direction, is arranged in Y-direction piezoelectric stack 21 side through hole, is fixed by trip bolt four; Z-direction displacement transducer is consistent with Z-direction piezoelectric stack three direction, is arranged on Z-direction block, in Z-direction piezoelectric stack three side, is fixed by trip bolt five.

4. the system of elliptic motion exposure in a kind of Moving Workpieces femtosecond laser processing according to claim 3, it is characterized in that: described in there is the workbench of hinge arrangement by objective table, X is to drive block, Y-direction drive block, stiff end one, stiff end two is formed by connecting by the flexible hinge between them, described objective table is by flexible hinge one, flexible hinge two, flexible hinge three, flexible hinge four connects to drive block with X, X to drive block by compound hinges one, compound hinges two, compound hinges three, compound hinges four is connected with Y-direction drive block, compound hinges one and compound hinges two are symmetrical structure relative to main body Y-direction center, compound hinges three and compound hinges four are symmetrical structure relative to main body Y-direction center, compound hinges one is symmetrically distributed in X to drive block two ends with compound hinges two, compound hinges three with compound hinges four, be connected with Y-direction drive block, compound hinges five and compound hinges six are symmetrical structure relative to main body X to center, compound hinges seven and compound hinges eight are symmetrical structure relative to main body X to center, compound hinges five is symmetrically distributed in Y-direction drive block two ends with compound hinges six, compound hinges seven with compound hinges eight, and both sides are connected with stiff end one, stiff end two respectively.

5. the system of elliptic motion exposure in a kind of Moving Workpieces femtosecond laser processing according to claim 4, is characterized in that: described compound hinges one, compound hinges two, compound hinges three or compound hinges four are joined end to end by four straight beam type hinges respectively and form.