CN106370372A - Focused shock wave excitation device for dynamic feature testing of microstructure of MEMS (micro-electromechanical system) - Google Patents

Abstract

The invention discloses a focused shock wave excitation device for testing the dynamic characteristics of MEMS microstructures, which includes a substrate, a manual three-axis displacement platform and a support, and a microstructure unit is arranged on the Z-axis sliding plate of the manual three-axis displacement platform ;The upper end of the support is provided with an ellipsoid cavity whose inner cavity is half an ellipsoid, and the first focus of the ellipsoid is located in the ellipsoid cavity; two needle electrode units are symmetrically arranged on both sides of the ellipsoid cavity; The needle tip of the needle electrode is located on the first focus cross section and points to the first focus; the MEMS microstructure is located at the second focus of the ellipsoid; the two needle electrodes are respectively electrically connected to the two poles of the high-voltage capacitor, and a There is a first air switch; the two poles of the high-voltage capacitor are respectively electrically connected to the high-voltage power supply, and the on-off is controlled by the second air switch. The advantages are: the interference of the vibration response of the base structure on the test results can be avoided, the non-contact excitation of the MEMS microstructure is realized, the excitation effect is good, and the dynamic characteristic parameters of the microstructure are convenient to test.

Description

A focused shock wave excitation device for testing the dynamic characteristics of MEMS microstructures

technical field

The invention belongs to the technical field of micromechanical electronic systems, and in particular relates to a focused shock wave excitation device for testing the dynamic characteristics of MEMS microstructures.

Background technique

Due to the advantages of low cost, small size and light weight, MEMS microdevices have broad application prospects in many fields such as automobile, aerospace, information communication, biochemistry, medical treatment, automatic control and national defense. For many MEMS devices, the micro-displacement and micro-deformation of their internal microstructures are the basis for the realization of device functions. Therefore, accurate testing of dynamic characteristic parameters such as the amplitude, natural frequency, and damping ratio of these microstructures has become the key to developing MEMS products. important content.

In order to test the dynamic characteristic parameters of the microstructure, it is first necessary to make the microstructure vibrate, that is, to excite the microstructure. Due to the small size, light weight and high natural frequency of MEMS microstructures, the excitation methods and excitation devices in traditional mechanical mode testing cannot be applied to the vibration excitation of MEMS microstructures. In the past two decades, researchers at home and abroad have made a lot of explorations on the vibration excitation methods of MEMS microstructures, and have developed some excitation methods and corresponding excitation devices that can be used for MEMS microstructures. Among them, She Dongsheng et al. introduced a shock-based base excitation device in the article "Shock Wave-Based MEMS Microstructure Base Shock Excitation Method". This device has the advantages of large excitation bandwidth and wide application range. application potential. However, the main disadvantage of this device is that the device uses an elastic base to excite the microstructure, so when the non-contact optical vibration measurement method is used to test the dynamic characteristics of the microstructure, the vibration response obtained The signal will inevitably contain the vibration response of the base structure, which will make it very difficult to obtain the dynamic characteristic parameters of the microstructure.

Contents of the invention

The technical problem to be solved by the present invention is to provide a focused shock wave excitation device for testing the dynamic characteristics of MEMS microstructures, which can avoid the interference of the vibration response of the base structure on the test results and realize the non-contacting The excitation effect is good, and it is convenient to test the dynamic characteristic parameters of the MEMS microstructure.

In order to solve the above problems, the present invention adopts the following technical solutions:

A focused shock wave excitation device for testing the dynamic characteristics of MEMS microstructures, including a substrate, on which a manual three-axis displacement platform and a support are arranged, and a microstructure is arranged on the Z-axis sliding plate of the manual three-axis displacement platform unit; the microstructure unit includes a mounting sleeve, a stepped mounting hole is provided in the mounting sleeve, and a MEMS microstructure is installed at the bottom of the mounting hole through a microstructure mounting plate; Optical glass plate;

An ellipsoid cavity is provided at the upper end of the support, and the inner cavity of the ellipsoid cavity is a half ellipsoid, and the first focus of the ellipsoid is located in the ellipsoid cavity; two needles are arranged symmetrically on both sides of the ellipsoid cavity. The electrode unit, each needle electrode unit includes a shaft sleeve fixed on the ellipsoid cavity and nested in sequence, a spring mounting seat and an outer sleeve, a sliding sleeve is arranged inside the outer sleeve, the outer edge of the sliding sleeve is stepped shaft shape and the front end is formed by The central hole of the spring mounting seat and the shaft sleeve penetrates and inserts into the inner cavity of the ellipsoid cavity, and a needle electrode covered with an insulating sleeve is arranged in the central hole at the front end of the sliding sleeve; There is a return spring between the sleeves, and an adjustment screw is threaded at the center of the sleeve. The front end of the adjustment screw is against the outer end of the sliding sleeve to adjust the axial position of the needle electrode; the needle points of the needle electrodes of the two needle electrode units are located at On the cross-section of the first focus of the ellipsoid and pointing to the first focus of the ellipsoid; the MEMS microstructure is located at the second focus of the ellipsoid on one side of the opening of the ellipsoid cavity;

The needle electrodes of the two needle electrode units are respectively electrically connected to the two poles of the high-voltage capacitor, and a first air switch is arranged between one needle electrode and the high-voltage capacitor to control on-off; the two electrodes of the high-voltage capacitor are respectively electrically connected to the positive pole of the high-voltage power supply The negative pole is controlled on and off by the second air switch.

As a further preference, the insulating sleeve is a ceramic tube and is fixed to the front end of the sliding sleeve by a top screw.

As a further preference, the installation sleeve is installed on the Z-axis slide plate through a horizontal support.

As a further preference, the microstructure mounting plate is fixed on the annular plane at the bottom of the mounting hole by uniformly distributed screws on the circumference, and a through hole corresponding to the small hole at the bottom of the mounting hole is provided on the microstructure mounting plate. MEMS The microstructures are bonded to the microstructure mounting plate.

As a further preference, the bushing, the spring mount and the outer sleeve are respectively fixed on the ellipsoidal cavity by screws, wherein the outer edge of the bushing is stepped and the front part is inserted into the mounting holes on both sides of the ellipsoidal cavity , the sliding gap fits between the sliding sleeve and the shaft sleeve.

As a further preference, the adjusting screw is a hollow structure and correspondingly communicates with the central hole of the sliding sleeve for passing through the wire connecting the needle electrode.

The beneficial effects of the present invention are: since the inner cavity of the ellipsoid cavity is a half ellipsoid, the first focus of the ellipsoid is located in the ellipsoid cavity, and the needle tips of the two needle electrode units are located at the center of the first focus of the ellipsoid. On the cross-section and pointing to the first focus of the ellipsoid, the MEMS microstructure is located at the second focus of the ellipsoid, thus realizing discharge through two needle electrodes, and using the ellipsoid of the ellipsoid cavity to discharge the The generated shock wave is focused, and the focused shock wave is used to shock and excite the MEMS microstructure at the second focus of the ellipsoid. On the one hand, the elastic base structure is canceled in the structural design, so that the shock wave directly acts on the MEMS microstructure. Structurally, when the dynamic characteristics of the MEMS microstructure are tested using the non-contact optical vibration measurement method, the vibration response signal obtained will not include the vibration response of the base structure, so that the dynamic characteristic parameters of the MEMS microstructure can be obtained It becomes easier and realizes the non-contact excitation of the MEMS microstructure, which can avoid the interference of the vibration response of the base structure on the test results; The excitation ability of the excitation device is improved, the excitation effect is good, and the dynamic characteristic parameters of the MEMS microstructure are convenient to be tested.

Description of drawings

Fig. 1 is a schematic diagram of the three-dimensional structure of the present invention.

Figure 2 is a top view of the present invention.

Figure 3 is a side view of the present invention.

Fig. 4 is a cross-sectional view along line A-A of Fig. 2 .

Fig. 5 is a three-dimensional structure diagram of the needle electrode unit of the present invention.

Fig. 6 is a cross-sectional view of the structure of the needle electrode unit of the present invention.

Fig. 7 is a three-dimensional structure diagram of the microstructure unit of the present invention.

Fig. 8 is a front view of the microstructure unit.

Fig. 9 is a C-C sectional view of Fig. 8 .

Fig. 10 is a circuit block diagram of the present invention.

In the figure: 1. substrate, 2. support, 3. ellipsoidal cavity, 301. ellipsoidal surface, 4. microstructure unit, 401. mounting sleeve, 402. screw, 403. pressure plate, 404. optical glass plate, 405 .MEMS microstructure, 406. screw, 407. microstructure mounting plate, 5. needle electrode unit, 501. adjustment screw, 502. jacket, 503. spring mounting seat, 504. shaft sleeve, 505. top screw, 506. slide Cover, 507. Insulation sleeve, 508. Needle electrode, 509. Return spring, 6. Manual three-axis translation stage, 7. Bottom plate, 8. Screw, 9. Z-axis sliding plate, 10. Horizontal support, 11. First Air switch, 12. Second air switch, 13. High voltage capacitor, 14. High voltage power supply.

detailed description

As shown in Fig. 1-Fig. 3, a focused shock excitation device for MEMS microstructure dynamic characteristic test related to the present invention includes a substrate 1 on which a manual three-axis translation stage 6 and a support 2 are arranged. , the manual three-axis translation stage 6 is installed on a bottom plate 7, and the bottom plate 7 is fixed on the base plate 1 by screws 8. A microstructure unit 4 is provided on the Z-axis slide plate 9 of the manual three-axis displacement table 6;

As shown in Figures 7-9, the microstructure unit 4 includes a mounting sleeve 401 installed on the Z-axis slide plate 9 through a horizontal support 10, and a stepped mounting hole is provided in the mounting sleeve 401. The bottom of the mounting hole is equipped with a MEMS microstructure 405 through a microstructure mounting plate 407; There is a through hole corresponding to the small hole at the bottom of the mounting hole, and the MEMS microstructure 405 is glued on the microstructure mounting plate 407 . An optical glass plate 404 is press-fitted at the outer port of the mounting hole through a pressure plate 403 , and the optical glass plate 404 is embedded in the outer end of the mounting hole.

The support 2 is fixed on the base plate 1 by screws, and an ellipsoid cavity 3 is supported and fixed at the upper end of the support 2. The inner cavity of the ellipsoid cavity 3 is a half ellipsoid 301, and the first part of the ellipsoid 301 is One focal point is located in the ellipsoid cavity 3 , and the second focal point is located on the side of the microstructure unit 4 . Two needle electrode units 5 are installed symmetrically on both sides of the ellipsoid cavity 3 .

As shown in Figures 4-6, each needle electrode unit 5 includes a shaft sleeve 504, a spring mounting seat 503, and an outer sleeve 502 that are fixed on the ellipsoid cavity 3 by screws and nested in sequence, wherein the outer edge of the shaft sleeve 504 It is stepped and the front part is inserted into the installation holes provided on both sides of the ellipsoid cavity 3 , the spring mounting seat 503 is sleeved on the large-diameter rear end of the shaft sleeve 504 , and the outer sleeve 502 is sleeved outside the spring mounting seat 503 . A sliding sleeve 506 is provided inside the outer sleeve 502. The outer edge of the sliding sleeve 506 is in the shape of a stepped shaft and the front end is passed through the central hole of the spring mounting seat 503 and the shaft sleeve 504 and inserted into the inner cavity of the ellipsoid cavity 3. The sliding sleeve 506 and Sliding gap fit between the shaft sleeves 504 . A needle electrode 508 covered with an insulating sleeve 507 is arranged in the center hole of the front end of the sliding sleeve 506 . The insulating sleeve 507 is a ceramic tube and is fixedly inserted into the front end of the sliding sleeve 506 through two jacking wires 505 . A reset spring 509 is sleeved between the outer end of the spring mounting seat 503 and the sliding sleeve 506, and an adjusting screw 501 is threadedly connected in the center hole of the outer cover 502, and the front end of the adjusting screw 501 leans against the outer end of the sliding sleeve 506 for use. Adjust the axial position of the needle electrode 508; the needle points of the needle electrodes 508 of the two needle electrode units 5 are on an axis and are located on the cross section of the first focus of the ellipsoid 301, and the needle points of the two needle electrodes 508 point to the ellipsoid from both sides The first focal point of 301; the MEMS microstructure 405 is located at the second focal point of the ellipsoidal surface 301 on one side of the opening of the ellipsoid cavity 3; the adjusting screw 501 is a hollow structure and communicates with the center hole of the sliding sleeve 506 correspondingly, A lead for passing through the connection pin electrode 508 .

As shown in Figure 10, the shock wave excitation device is also provided with a high-voltage capacitor 13 and a high-voltage power supply 14, and the needle electrodes 508 of the two needle electrode units 5 are respectively electrically connected with the two poles of the high-voltage capacitor 13 through wires, and one needle electrode 508 and A first air switch 11 is provided between the high-voltage capacitors 13 to control on-off; the two poles of the high-voltage capacitor 13 are electrically connected to the positive and negative poles of the high-voltage power supply 14 through wires, and are controlled on-off by the second air switch 12 .

When working, first put the first air switch 11 and the second air switch 12 in the off state, respectively adjust the adjustment screw rods 501 of the two needle electrode units 5, and adjust the sliding sleeve 506 through the adjustment screw rod 501 so that the sliding sleeve is in the position of the return spring. Back under the action of 509, ensure that the distance between the two needle electrodes 508 is greater than the maximum air breakdown gap after the high-voltage capacitor 13 is fully charged; secondly, adjust the manual three-axis translation stage 6 so that the MEMS microstructure 405 is located on the second ellipsoidal surface 301 At the focal point; then, close the second air switch 12, use the high-voltage power supply 14 to charge the high-voltage capacitor 13, and then disconnect the second air switch 12 after charging is completed; finally, close the first air switch 11, and adjust the two needle electrodes at the same time The adjustment screw 501 of the unit 5 makes the two needle electrodes 508 approach the first focus of the ellipsoid 301 in the ellipsoid cavity 3 at the same time, when the distance between the needle tips of the two needle electrodes 508 satisfies the air breakdown condition under the current charging voltage When the air gap is broken down, the discharge is completed and a shock wave is generated, and through the focusing of the ellipsoidal surface 301 in the ellipsoidal cavity 3, the shock wave impacts the MEMS microstructure 405 at the second focus of the ellipsoidal surface 301 in the ellipsoidal cavity 3 Perform non-contact shock excitation.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the present invention, and it can be easily understood by those skilled in the art Therefore, the invention is not limited to the specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims (6)

1. a kind of focusing shock wave exciting bank for the test of mems micro-structure dynamic characteristics, including substrate, is characterized in that: in base Plate is provided with manual three-shaft displacement platform and bearing, is provided with microstructure unit on the z-axis slide carriage of manual three-shaft displacement platform；Described micro- Construction unit includes an installation set, is provided with stepped installing hole in installation set, is pacified by micro structure in installing hole inner bottom part Dress plate is provided with mems micro structure；At installing hole external port, optical flat is pressed with by pressing plate；

It is provided with ellipsoid cavity in bearing upper end, the inner chamber of ellipsoid cavity is half ellipsoid, and the first focus of this ellipsoid is located at In ellipsoidal cavity body；It is symmetrically arranged on two with two needle electrode units in ellipsoid cavity, each needle electrode unit includes being separately fixed at On ellipsoid cavity and successively nested axle sleeve, spring mounting seat and overcoat, are provided with slip cap in overcoat, and slip cap outer rim is rank Terraced shaft-like and front end is passed by the centre bore of spring mounting seat and axle sleeve and is inserted into ellipsoidal cavity intracoelomic cavity, in slip cap front end Heart in the hole is provided with the needle electrode that outside is cased with insulation sleeve；It is provided with reset bullet between spring mounting seat outer end seam and slip cap Spring, has been threaded connection adjusting screw rod in overcoat center, adjusting screw rod front end acts against slip cap outer end, for metering needle The axial location of electrode；The needle electrode needle point of two needle electrode units is located on the cross section of ellipsoid first focus and points to ellipse First focus of sphere；Described mems micro structure is located at the second focal point of ellipsoidal cavity intracoelomic cavity opening side ellipsoid；

The needle electrode of two needle electrode units is electrically connected with the two poles of the earth of high-voltage capacitance respectively, a needle electrode and high-voltage capacitance it Between be provided with first air switch control break-make；The two poles of the earth of described high-voltage capacitance are electrically coupled to the both positive and negative polarity of high voltage power supply respectively, and Break-make is controlled by the second air switch.

2. a kind of focusing shock wave exciting bank for the test of mems micro-structure dynamic characteristics according to claim 1, its Feature is: described insulation sleeve is earthenware and is fixed on slip cap front end by jackscrew.

3. a kind of focusing shock wave exciting bank for the test of mems micro-structure dynamic characteristics according to claim 1, its Feature is: described installation set is arranged on described z-axis slide carriage by a horizontal seat.

4. a kind of focusing shock wave exciting bank for the test of mems micro-structure dynamic characteristics according to claim 1, its Feature is: described micro structure installing plate is fixed on the planar annular of installing hole inner bottom part by the screw of circumference uniform distribution, micro- Structure installing plate is provided with the through hole corresponding with described installing hole small hole at bottom part, and mems micro structure is bonded in micro structure installing plate On.

5. a kind of focusing shock wave exciting bank for the test of mems micro-structure dynamic characteristics according to claim 1, its Feature is: described axle sleeve, spring mounting seat and overcoat are fixed by screws on ellipsoid cavity respectively, and its bottom bracket axle outer rim is rank Scalariform and front portion is inserted into the installation in the hole being located at ellipsoid cavity both sides, glade plane space cooperation between described slip cap and axle sleeve.

6. a kind of focusing shock wave exciting bank for the test of mems micro-structure dynamic characteristics according to claim 5, its Feature is: described adjusting screw rod is hollow-core construction and corresponding with slip cap centre bore communicates, for through connection the leading of needle electrode Line.