CN102967510B - Method and apparatus for applying forces perpendicular to cantilever beam - Google Patents

Abstract

The invention relates to a method and an apparatus for applying forces perpendicular to a cantilever beam. The method comprises applying load force to an on-sheet mechanical microprobe with a curved-surface probe through a probe on a probe station; applying forces to the cantilever beam through the curved-surface probe by the on-sheet mechanical microprobe, and meanwhile rotating the on-sheet mechanical microprobe so that the forces to the cantilever beam are always perpendicular to the cantilever beam during a bending process. According to the invention, during the process of applying the forces to the detected cantilever beam, elastic forces in the direction of the cantilever beam are not generated, and frictional forces are either not generated; and due to a buffer effect of the mechanical microprobe, the application of the load force is relatively stable and the measure results are relatively accurate.

Description

A kind of method and device applying perpendicular to the acting force of semi-girder

Technical field

The invention belongs to microelectromechanical systems (MEMS) mechanics parameter detection technique field, be specifically related to a kind of semi-girder is continuously applied to the method perpendicular to the load force of semi-girder, and the device that adopts the method, be applied in especially semi-girder is carried out to crooked test, the field of detection of broken intensity, torsion bond strength.

Background technology

Since the nineties, microelectromechanical systems (MEMS) technology has entered the high speed development stage, is not only because concept is novel, and is because MEMS device is compared with traditional devices, has miniaturization, the prospect feature that integrated and performance is more excellent.Nowadays MEMS has been widely used in the fields such as automobile, Aero-Space, information control, medical science, biology.

But for this produced MEMS device of silicon technology that utilizes, along with MEMS device is done more and more littlely, the size of microstructure enters micron dimension, the impact that the problems such as the absolute error in silicon technology in processing dimension, rough surface are brought to mechanics parameters such as microstructure intensity, elastic modulus, rigidity, physical dimensions, more and more can not ignore.Now need analytical approach, computing method to microstructure model to revise accordingly, and the mechanics parameter that accurately extracts microstructure in these silicon technology process has just become inevitable Important Problems.

Semi-girder is as the simplest microstructure in MEMS, and technique is very simple, and the other influences factor that need to control is fewer, is suitable as very much detection architecture, is used for extracting individual event mechanical property parameters.When utilizing cantilever beam structure to carry out mechanics parameter detection, conventionally need to carry out different crooked experiments to semi-girder, require in some cases in the whole BENDING PROCESS of semi-girder, suffered power is perpendicular to semi-girder all the time, for example by the mode of bending cantilever beam, measure anchor point (ANCHOR) and locate torsional fracture intensity, if the acting force that semi-girder is suffered non-perpendicular to semi-girder, fracture is exactly that twisting action and tension and compression effect cause jointly, and the torsional fracture intensity measuring is not just real torsional fracture intensity.The classic method of carrying out this crooked experiment is to utilize the probe of probe station, but because the probe of probe station can only translation in measuring process, will inevitably produce the acting force (elastic force or force of sliding friction) along semi-girder direction to semi-girder, also the method that has in addition some to utilize microprobe on sheet to apply acting force (is compared the former, the double swerve of the probe that has improved probe station when doing translational motion), but due to these probe design is all mainly to take translation as main, keep away equally the unavoidable generation along the acting force in semi-girder direction, this has brought inevitable inaccuracy to measurement result now.

Summary of the invention

Known by analysis above, when need to being continuously applied the acting force perpendicular to semi-girder direction to semi-girder, existing method can produce elastic force or the force of sliding friction along semi-girder direction conventionally, and this has brought inevitable uncertainty to measurement result.The object of the invention is to propose a kind of method and device being continuously applied perpendicular to the acting force of semi-girder, by microprobe on the sheet of appropriate design, the acting force of probe station probe is cushioned and break-in, thereby kept in whole semi-girder BENDING PROCESS, suffered acting force is perpendicular to semi-girder all the time.

For achieving the above object, the present invention adopts following technical scheme:

Apply the method perpendicular to the acting force of semi-girder, its step comprises:

1) by probe station probe, to thering is microprobe on the sheet of curved surface probe, apply load force;

2) described upper microprobe applies acting force by curved surface probe to semi-girder, simultaneously on this sheet microprobe rotate so that the acting force that this semi-girder is subject in BENDING PROCESS all the time perpendicular to this semi-girder.

Further, by single-ended clamped semi-girder and the probe described upper microprobe that be composed of a fixed connection, described upper microprobe carries out described rotation around the anchor point of described single-ended clamped semi-girder.

Further, the cross section of the pillar of described anchor point is rectangle.

Apply the device perpendicular to the acting force of semi-girder, it comprises semi-girder, to the probe station probe that applies microprobe on the sheet of acting force on this semi-girder and apply load force to microprobe on this sheet; The probe of described upper microprobe is curved surface form, and the forms of motion of described upper microprobe is for rotating.

Further, described upper microprobe comprises a single-ended clamped semi-girder being fixedly connected with described probe, goes up microprobe for described and carries out described rotation around the anchor point of this single-ended clamped semi-girder.

Further, the cross section of the pillar of described anchor point is rectangle.

Further, on sheet, the semi-girder length of microprobe is greater than the length of tested semi-girder.

The present invention proposes and utilize microprobe on sheet to cushion the probe of probe station and the thinking of break-in, by microprobe on probe station probe actuation sheet, then by microprobe on sheet, semi-girder is carried out to direct output load power.The benefit of this method is to cushion the probe of probe station, improves and executes loaded stability; And this microprobe is through reasonably design, can change the direction of probe station probe acting force, can make the suffered acting force of semi-girder all the time perpendicular to semi-girder.Compare with the existing method that semi-girder is applied to vertical direction load, the advantage of this method is:

The inventive method can not produce along the elastic force in semi-girder direction in applying process, can not produce the friction force in any direction yet, make semi-girder suffered acting force in BENDING PROCESS be perpendicular to all the time semi-girder, and the buffer action due to microprobe, make load force apply more stablely, reduce the instant impact bringing because manual operation is improper.So while measuring the mechanics parameter relevant to pure torsion, the result of measurement is just more accurate.

Accompanying drawing explanation

Fig. 1 is the schematic diagram perpendicular to the device of the acting force of semi-girder that applies of embodiment; Wherein: the single-ended clamped semi-girder of 1-; The tested semi-girder of 2-; 3-probe; The width of microprobe on W1-sheet; The width of the tested semi-girder of W2-; The length of the tested semi-girder of L1-; The length of microprobe on L2-sheet; The spacing of microprobe and semi-girder on W-sheet.

Fig. 2 is the probe vertical view of embodiment.

Fig. 3 is the anchor point schematic diagram of embodiment.

Fig. 4 is two of the embodiment not position vertical views of probe and beam in the same time.

Fig. 5 be embodiment apply loading process schematic diagram

Fig. 6 is the probe curved surface slope schematic diagram of embodiment.

Fig. 7 is that the coordinate of embodiment is set up schematic diagram.

Embodiment

Below by specific embodiment and coordinate accompanying drawing, the present invention is described in detail.

As shown in Figure 1, arrow locations is the application of force direction of probe station probe, by the microprobe after appropriate design transmit, break-in, the semi-girder on the right is applied to acting force.In Fig. 1, the 1st, single-ended clamped semi-girder, probe 3 is to carry on this semi-girder, forms microprobe system.This microprobe has two features: 1) probe is curved design, as shown in Figure 2; 2) motion of probe is rotation formula, and probe rotates around the anchor point of Fig. 1 left side beam.

For the distortion of semi-girder as shown in Figure 1, comprise two parts: the one, the torsional deflection of anchor point (ANCHOR); The 2nd, the bending of girder construction, comprises the bending of single-ended clamped semi-girder 1 and the bending of tested semi-girder 2.Two processes can separate to be analyzed:

The anchor point pillar of the present embodiment adopts square-section, and as shown in Figure 3, the torsion angle in its twist process is:

$\mathrm{\δ}=\frac{\mathrm{Tl}}{{\mathrm{GI}}_t}=\frac{\mathrm{Tl}}{{\mathrm{G\βhb}}^3}---\left(1\right)$

Wherein G is modulus of shearing, I _tfor second polar moment of area, T is moment of torsion, the height that l is ANCHOR, h is the length of ANCHOR, b is the wide of ANCHOR, and as shown in Figure 3, factor beta can obtain (relevant with h/b ratio) by query material Mechanical Data form " factor alpha during Rectangular Section Lever Torsion, β and γ ".

Sag equation and the equations of rotating angle of rectangular cross section beam are:

$y\left(x\right)=-\frac{{{\mathrm{Px}}_0}^2}{6\mathrm{EI}}[3L-x_0]---\left(2\right)$

$\mathrm{\θ}\left(x\right)=\frac{1}{\mathrm{EI}}({\mathrm{PLx}}_0-\frac{P}{2}{x_0}^2)$ (when θ is very little) (3)

Wherein P is the suffered acting force of back end (being the amount of force that middle probe of the present invention applies), x ₀for the position size along in semi-girder direction, L is that (as shown in Figure 1,, for single-ended clamped semi-girder 1, its beam length is L2 to beam length; For tested semi-girder 2, its beam length is L1), I is moment of inertia, E is elastic modulus.

By simultaneous (1), (2), (3) equation, can obtain shown in Fig. 1 the deflection equation with the semi-girder of ANCHOR, the i.e. curvilinear equation of semi-girder profile in deformation process.

As shown in Figure 4, figure (a) is the location drawing of some moment probes and semi-girder to the schematic diagram of this microprobe when carrying out practical operation, and A point is the application point of acting force between probe and semi-girder now; Figure (b) be the location drawing of next moment probe and semi-girder, and A1 and A2 are respectively the position of A point on probe and semi-girder, and now between probe and semi-girder the application point of acting force be B point.If will apply in the process of load force at probe, continue to keep the direction of acting force to be perpendicular to semi-girder, friction force is necessary for zero (under this structure situation, in the direction non-perpendicular to beam, can there is not elastic force), so camber line distance A 1B and camber line distance A 2B must equate, be that probe and semi-girder do not have relative sliding, do not have force of sliding friction.If any two moment (or any two different θ positions) all guarantee the camber line distance between two application points on probe and semi-girder and equate, be between probe and semi-girder, there is no relative sliding and tendency toward sliding, whole, apply in loading process, semi-girder suffered acting force is perpendicular to semi-girder all the time.

Suppose that the load force that at a time the tested semi-girder of t1 is subject to is P, the application point of power is the i.e. L1 as shown in Figure 1 of L(to the length of semi-girder root), as shown in Fig. 3 (a).Equations of rotating angle now can obtain according to formula (1) (3):

${\mathrm{\θ}}^{\′}\left(x\right)=\frac{1}{\mathrm{EI}}({\mathrm{PLx}}_0-\frac{P}{2}{x_0}^2)+\frac{\mathrm{PLl}}{{\mathrm{G\βhb}}^3}---\left(4\right)$

Next constantly t2 load force be changed to △ P(and level off to infinitesimal), the application point of power levels off to infinitesimal to the length variations △ L(of semi-girder root), equations of rotating angle is:

${\mathrm{\θ}}^{\′\′}\left(x\right)=\frac{1}{\mathrm{EI}}[(P+\mathrm{\ΔP})(L+\mathrm{\ΔL})x_0-\frac{(P+\mathrm{\ΔP})}{2}{x_0}^2]+\frac{(P+\mathrm{\ΔP})(L+\mathrm{\ΔL})l}{{\mathrm{G\βhb}}^3}---\left(5\right)$

X in above formula (4), (5) ₀for the position in semi-girder length.

In order to obtain coordinate figure, set up coordinate system (semi-girder is tested structure) as shown in Figure 7, wherein, initial point is arranged in Fig. 7 O point place, and x axle is perpendicular to semi-girder, and y axle is along semi-girder direction, and the coordinate figure that can obtain the application point of power by (1) (2) formula is:

The t1 moment: $(x_1,y_1)=(L\·\sin [\frac{\mathrm{PLl}}{{\mathrm{G\βhb}}^3}+\arctan \left(\frac{{\mathrm{PL}}^2}{3\mathrm{EI}}\right)],L\·\cos [\frac{\mathrm{PLl}}{{\mathrm{G\βhb}}^3}+\arctan \left(\frac{{\mathrm{PL}}^2}{3\mathrm{EI}}\right)\left]\right)$

The t2 moment: $(x_2,y_2)=((L+\mathrm{\ΔL})\·\sin [\frac{(P+\mathrm{\ΔP})(L+\mathrm{\ΔL})l}{{\mathrm{G\βhb}}^3}+\arctan \left(\frac{(P+\mathrm{\ΔP}){(L+\mathrm{\ΔL})}^2}{3\mathrm{EI}}\right)],$

$(L+\mathrm{\ΔL})\·\cos [\frac{(P+\mathrm{\ΔP})(L+\mathrm{\ΔL})l}{{\mathrm{G\βhb}}^3}+\arctan \left(\frac{(P+\mathrm{\ΔP}){(L+\mathrm{\ΔL})}^2}{3\mathrm{EI}}\right)])$

Suppose t1 original state constantly, the top of left side probe beam is rotation alpha degree, as shown in Figure 5; At t2 constantly, the beam of probe rotates Δ α degree again.And as shown in Figure 6, establish can find out that k is different at different θ (different camber line position in other words).

It should be noted that, α can calculate by t1 coordinate and boundary condition constantly.This calculating is that the state in 0 moment is exactly boundary condition by initial state (state in 0 moment) the successively process of iteration.The corner that formula (4) calculates above represents the corner of any position on semi-girder, and the α be here semi-girder top corner, i.e. value when x0 gets L2 in Fig. 1 in formula (4).But now do not need formula (4) to ask this α, because for probe beam, only need the profile in its when distortion, need not be concerned about how its stressed meeting is out of shape and rotates, the angle that while therefore only representing the original state in the t1 moment with this character of α here, the probe beam on the left side has rotated.

Because curved surface and the semi-girder of probe is tangent all the time, so at t2 constantly, on the slope at semi-girder application point place and probe curved surface, the slope of this application point equates, can obtain:

According to the curved surface slope k on probe, can calculate the coordinate that B orders and be:

Wherein ρ be A point to the distance at probe beam ANCHOR center, A coordinate figure i.e. the t1 coordinate figure of the application point of power constantly above.

And the B point coordinate of calculating according to the curved surface slope on probe equates with the coordinate figure of the application point of t2 above power constantly, that is:

According to formula (6), (7), (8), can eliminate Δ α, Δ P, from zero at first, constantly start iterative computation, can obtain the k value at diverse location place on probe, according to this k value, can obtain the radius-of-curvature at diverse location place on probe.Said method calculates slightly complicated, can use software evaluation solution.

In sum, the present invention proposes that microprobe on the sheet that utilizes particular design cushions the probe of probe station and the load applying method of break-in, and the size design of microprobe is with reference to content above.

The applying method continuing perpendicular to the acting force of semi-girder of the present invention, is conducive to the detection of the mechanics parameter relevant to pure torsion.Below in conjunction with the test of the torsion bond strength of small bonding (anode linkage) area, further illustrate the use procedure of the method.The size of supposing detected semi-girder has designed, and the ensuing the inventive method of utilizing is carried out subtest, mainly comprises the following steps:

1) according to the length of detected semi-girder, and the length of ANCHOR, design size and the position of the special microprobe in the present invention, the specific design method summary of the invention that sees above, and make domain.

The probe depth of beam of this microprobe is by step 2 below) technological parameter determine.The length of probe beam, width determines according to tested beam parameter, and in order to make software numerical evaluation can access solution, the length of probe beam need to be greater than the length of tested semi-girder, and (as shown in Figure 1, L2>L1), width is applicable to domain and just can.These parameters have been determined, just can calculate K value according to above-mentioned formula.

2) technique flow.The technique adopting is bonding deep etching release standard technique, mainly comprises:

A) adopt ASE(Advanced silicon etch, advanced silicon etching) method etching silicon wafer, etching depth is 4 μ m, carves ANCHOR step;

B) adopt BHF(Buffer HF, buffered hydrofluoric acid) etching glass, corrosion depth is sputtered with Ti/Pt/Au, anti-footing effect;

C) silicon chip and glass sheet anode linkage;

D) KOH attenuate silicon face, remaining thick 75 ± 5 μ m;

E) ASE silicon chip, structure discharges, and obtains microprobe on sheet.

3) probe station test.

As shown in Figure 1, at arrow locations place, apply probe station probe, by microprobe on sheet, be delivered to semi-girder, the transverse deflection on tested semi-girder top, the right while recording bonding face (anchor point position place) fracture, in the time of can calculating bonding face fracture, (what be now subject to is pure twisting action to the suffered moment of torsion of bonding face, without any tension and compression effect), can obtain the torsion bond strength of small bonding (anode linkage) area.

By an embodiment, describe above an application of the inventive method, detected the torsion bond strength of the small bonding face of anode linkage.But it should be noted that, the inventive method is applicable to other with detections of the relevant mechanics parameter of pure twisting action, such as the torsional fracture intensity of beam etc.Those skilled in the art is to be understood that, within not departing from the scope of this patent essence, keep microprobe in the present invention 1) curved surface probe and 2) outside two kinds of features of rotation formula, can make certain variation and modification to structure, its its preparation process is also not limited to the bonding deep etching release standard technique in the present embodiment.Protection scope of the present invention should be as the criterion with described in claim.

Claims (7)

1. apply the method perpendicular to the acting force of semi-girder, its step comprises:

1) by probe station probe, to thering is microprobe on the sheet of curved surface probe, apply load force;

2) described upper microprobe applies acting force by curved surface probe to semi-girder, simultaneously on this sheet microprobe rotate so that the acting force that this semi-girder is subject in BENDING PROCESS all the time perpendicular to this semi-girder;

On the curved surface of described probe, the computing method of the radius-of-curvature at diverse location place are:

A) set up the torsion angle equation in the square-section twist process of tested semi-girder anchor point pillar:

Wherein G is modulus of shearing, I _tfor second polar moment of area, T is moment of torsion, the height that l is ANCHOR, and the length that h is ANCHOR, what b was ANCHOR is wide, and β is Rectangular Section Lever Torsion coefficient;

Set up the sag equation of tested semi-girder:

Wherein P is the suffered acting force of back end, x ₀for the position size along in semi-girder direction, L is beam length, and I is moment of inertia, and E is elastic modulus;

B) set up coordinate system, its x axle is perpendicular to semi-girder, and y axle is along semi-girder direction, obtains on sheet the coordinate figure of the application point of acting force between microprobe and tested semi-girder to be by formula (1), (2):

The t1 moment:

The t2 moment:

Be located at t1 constantly, the beam of left side probe is rotation alpha degree; At t2 constantly, the beam of probe rotates Δ α degree again, and establishes at t2 constantly, on the slope at semi-girder application point place and probe curved surface, the slope of this application point equates, that is:

If A point is the application point of acting force between t1 moment probe and semi-girder, B point is the application point of acting force between t2 moment probe and semi-girder; According to the curved surface slope k on probe, obtain the coordinate that B orders and be:

Wherein ρ be A point to the distance at probe beam ANCHOR center, the coordinate figure of the application point of the coordinate figure that this B is ordered and t2 power constantly equates, that is:

And then, according to formula (6), (7), (8), obtain the k value at diverse location place on probe, according to this k value, obtain the radius-of-curvature of corresponding position.

2. the method applying perpendicular to the acting force of semi-girder as claimed in claim 1, it is characterized in that: by single-ended clamped semi-girder and the probe described upper microprobe that be composed of a fixed connection, described upper microprobe carries out described rotation around the anchor point of described single-ended clamped semi-girder.

3. the method applying perpendicular to the acting force of semi-girder as claimed in claim 1, is characterized in that: on sheet, the semi-girder length of microprobe is greater than the length of tested semi-girder.

4. the method applying perpendicular to the acting force of semi-girder as claimed in claim 1, is characterized in that: use software to calculate the numerical solution of k value.

5. apply the device perpendicular to the acting force of semi-girder, it is characterized in that, comprise semi-girder, to the probe station probe that applies microprobe on the sheet of acting force on this semi-girder and apply load force to microprobe on this sheet; The probe of described upper microprobe is curved surface form, and the forms of motion of described upper microprobe is for rotating;

On the curved surface of described probe, the computing method of the radius-of-curvature at diverse location place are:

A) set up the torsion angle equation in the square-section twist process of tested semi-girder anchor point pillar:

Wherein G is modulus of shearing, I _tfor second polar moment of area, T is moment of torsion, the height that l is ANCHOR, and the length that h is ANCHOR, what b was ANCHOR is wide, and β is Rectangular Section Lever Torsion coefficient;

Set up the sag equation of tested semi-girder:

Wherein P is the suffered acting force of back end, x ₀for the position size along in semi-girder direction, L is beam length, and I is moment of inertia, and E is elastic modulus;

B) set up coordinate system, its x axle is perpendicular to semi-girder, and y axle is along semi-girder direction, obtains on sheet the coordinate figure of the application point of acting force between microprobe and tested semi-girder to be by formula (1), (2):

The t1 moment:

The t2 moment:

Be located at t1 constantly, the beam of left side probe is rotation alpha degree; At t2 constantly, the beam of probe rotates Δ α degree again, and establishes at t2 constantly, on the slope at semi-girder application point place and probe curved surface, the slope of this application point equates, that is:

If A point is the application point of acting force between t1 moment probe and semi-girder, B point is the application point of acting force between t2 moment probe and semi-girder; According to the curved surface slope k on probe, obtain the coordinate that B orders and be:

Wherein ρ be A point to the distance at probe beam ANCHOR center, the coordinate figure of the application point of the coordinate figure that this B is ordered and t2 power constantly equates, that is:

And then, according to formula (6), (7), (8), obtain the k value at diverse location place on probe, according to this k value, obtain the radius-of-curvature of corresponding position.

6. the device applying perpendicular to the acting force of semi-girder as claimed in claim 5, it is characterized in that: described upper microprobe comprises a single-ended clamped semi-girder being fixedly connected with described probe, go up microprobe for described and carry out described rotation around the anchor point of this single-ended clamped semi-girder.

7. the device applying perpendicular to the acting force of semi-girder as claimed in claim 5, is characterized in that: it is characterized in that: on sheet, the semi-girder length of microprobe is greater than the length of tested semi-girder.