JP3210966B2 - Electrostatic microactuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electrostatic micro-actuator, and more particularly, to an MO driving device and a D / D converter
The present invention relates to an electrostatic microactuator that can be suitably used as an actuator for various micro mechanisms such as a microlens driving actuator for various optical pickups in a VD driving device, a microstage, and a micro vibration isolation table.

[0002]

2. Description of the Related Art With the development of micromachine technology,
There is an increasing demand for high performance microactuators. In particular, a high-performance electrostatic actuator that is extremely small and has excellent controllability is demanded for the above-described MO driving device. From such a viewpoint, demand for an electrostatic microactuator has been increasing in these fields in recent years. There are many types of electrostatic microactuators, such as a rotary type, a comb type, and a cantilever type. However, in the above-mentioned fields, since it is necessary to drive an optical pickup or the like from an in-plane to an out-of-plane, that is, from a certain surface in a vertical direction, mainly a cantilever type and a cantilever type are used. Electrostatic microactuators have been used.

[0003]

However, the cantilever-type electrostatic microactuator has a problem that the driving force generation point is largely displaced from the axis in the driving direction during driving in the vertical direction. Further, since both ends of the double-supported-type electrostatic actuator are fixed, the stroke in the thickness direction is smaller than the length of the beam. Therefore, it was necessary to use an electrostatic microactuator larger than the theoretically required size for the object to be driven. This has also been a factor in increasing the size of the MO driving device and the like.

An object of the present invention is to provide a new electrostatic microactuator that can perform large driving in the vertical direction and that does not change the driving force generation point during driving.

[0005]

In order to achieve the above object, an electrostatic microactuator according to the present invention has a substrate, a substrate electrode insulating layer, a substrate electrode, a drive electrode insulating layer, and a supercooled liquid region. A drive electrode made of an amorphous alloy,
These are stacked in this order, and the drive electrode has a spiral shape.

The present inventors have conducted intensive studies to achieve the above object. As a result, a substrate electrode and a spiral driving electrode made of an amorphous alloy having a supercooled liquid region are formed on the substrate, and these are insulated by the substrate electrode insulating layer and the driving electrode insulating layer, respectively. Then, a voltage is applied between the substrate electrode and the driving electrode, and the driving electrode is driven by an electrostatic force generated by the voltage application. Then
The driving electrode moves up and down on the center axis of the spiral by the electrostatic force.

Therefore, the point at which the driving force of the electrostatic microactuator is generated always exists on the center axis of the spiral. Therefore, a constant driving force always acts on the object to be driven, and a large driving force can be applied. Further, the stroke can be increased as compared with a simple beam structure. This makes it possible to reduce the size of the electrostatic microactuator with respect to the object to be driven, as compared with the conventional electrostatic microactuator, and achieve downsizing of the MO driving device and the like.
The “supercooled liquid region” in the present invention refers to a temperature region (ΔTx) from a glass transition temperature (Tg) to a crystallization start temperature (Tx).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments of the present invention. 1 and 2 are perspective views showing an example of a preferred embodiment of the electrostatic microactuator of the present invention. FIG. 1 shows a case where the drive electrode is at the raised position, and FIG. 2 shows a case where the drive electrode is at the lowered position.

An electrostatic microactuator 1 shown in FIG.
0 denotes a substrate 1, a substrate electrode insulating layer 2, a substrate electrode 3,
It has a drive electrode insulating layer 5 and a drive electrode 8. These electrodes and the like are stacked in this order. The substrate electrode insulating layer 2 and the drive electrode insulating layer 5 are
And the substrate electrode 3 and the substrate electrode 3 and the drive electrode 8 are insulated and separated. A substrate electrode pad portion 4 is formed on the substrate electrode 3, and a drive electrode pad portion 7 is formed on the drive electrode 8. These serve as terminals of the substrate electrode 3 and the drive electrode 8, respectively, so that a voltage can be externally applied.

The drive electrode 8 has a spiral shape and is made of an amorphous alloy having a supercooled liquid region. An object to be driven is attached to the 8A portion of the drive electrode 8. An electric field generated by applying a voltage between the drive electrode pad portion 7 and the substrate electrode pad portion 4 enables driving in the vertical direction along the spiral center axis AA line. That is, when no voltage is applied between the pad portions, the drive electrode 8 is at the rising position, and as shown in FIG. 1, the spiral drive electrode 8 rises from the outer periphery toward the center,
It has a conical shape. On the other hand, when the voltage V is applied from the external power supply 9 between the pad portions, the drive electrode 8 is at the lowered position, and the drive electrode 8 is driven by an electric field generated between the substrate electrode 3 and the drive electrode 8 as shown in FIG. Numeral 8 is attracted to the substrate electrode 3 and further adsorbed on the substrate electrode 3 to form a planar spiral shape.

As described above, the drive electrode 8 is driven in the vertical direction, that is, in the vertical direction, along the AA line which is the spiral center axis, depending on whether or not a voltage is applied. At this time, the portion 8A to which the object to be driven is attached is also driven vertically along the line AA. Therefore, the drive electrode 8 and the portion 8A to which the object to be driven is attached are always driven in the same direction, so that the point at which the drive force is generated does not change during driving. Further, the stroke in the vertical direction also increases.

FIG. 3 is a perspective view showing another example of a preferred embodiment of the electrostatic microactuator of the present invention. The electrostatic microactuator 20 shown in FIG. 3 includes a substrate 11, a substrate electrode insulating layer 12, and substrate electrodes 13-1 to 13-1.
13-4, a drive electrode insulating layer 15, and a spiral drive electrode 18. These electrodes and the like are stacked in this order. The substrate electrode insulating layer 12 and the drive electrode insulating layer 15 separate and insulate the substrate 11 from the substrate electrode 13 and the substrate electrode 13 from the drive electrode 18, respectively. A drive electrode pad 17 is formed on the drive electrode 18, and substrate electrode pads 14-1 to 14-4 are formed on the substrate electrodes 13-1 to 13-4, respectively.

An electrostatic microactuator 2 shown in FIG.
In the case of 0, similarly to the case of the electrostatic microactuator 10 shown in FIGS. 1 and 2, the drive electrode 18 is driven vertically along the spiral central axis BB by applying a voltage between the pad portions. However, since the electrostatic microactuator 20 shown in FIG. 3 has the substrate electrode divided into four, it can be driven in multiple stages instead of two stages of the upper position and the lower position as shown in FIGS. Becomes

That is, when a predetermined voltage is applied between the drive electrode pad portion 17 and the first substrate electrode pad portion 14-1, a portion 18-1 of the drive electrode 18 and the first substrate electrode 13- An electric field is generated between the substrate electrode 13-1 and the substrate electrode 13-1. Next, when a predetermined voltage is applied between the drive electrode pad portion 17 and the second substrate electrode pad portion 14-2, the portion 18-2 of the drive electrode 18 is attracted to the substrate electrode 13-2. Similarly, the drive electrode pad portion 17 and the third substrate electrode pad portion 14-3, and the drive electrode pad portion 17 and the fourth substrate electrode pad portion 14-
When a predetermined voltage is applied between the driving electrode 18 and the substrate electrode 13
-Adsorb to 3 and 13-4.

Further, a difference between the driving electrode pad portion 17 and the first substrate electrode pad portion 14-1 and between the driving electrode pad portion 17 and the second substrate electrode pad portion 14-2 are different from those described above. When a predetermined voltage is applied, the drive electrode 18
18-5 and 18-6 are adsorbed to the substrate electrodes 13-1 and 13-2. Even in the case of driving in multiple stages as described above, the driving electrode 8 is vertically attracted to the substrate electrode 13-1 or the like, so that the driving is performed along the line BB and the portion 18A for attaching the object to be driven is provided. Also BB
Drive along the line. Therefore, the generation of the driving force does not change during driving. Further, the stroke in the vertical direction is also increased.

In performing such multi-stage driving, the number of divisions of the substrate electrode is preferably at least three times the overlapping number of the driving electrodes 18, and more preferably 3 to 60 times. In particular, a driving electrode having a double or triple spiral structure is used, and a substrate electrode divided into three or more times the number of the driving electrodes is used. Then, by sequentially applying a voltage from the substrate electrode near each base of the drive electrode, the drive direction at the time of driving in multiple stages and the drive method of the part for mounting the object to be driven more accurately match, The generation point of the driving force can be kept more constant. Furthermore, by using multiple springs, the repulsive force of the spring can be increased, so that the output of the actuator increases.

The material constituting the drive electrode of the electrostatic microactuator of the present invention must be made of an amorphous alloy having a supercooled liquid region as described above. Thereby, a spiral drive electrode that can be driven in the vertical direction as shown in FIGS. 1 to 3 can be configured. Such amorphous alloys include Zr—Cu—Al and Pd—Cu—S
i, Pd-Ni-P, and Au-Si can be exemplified.

As the material constituting the substrate, a semiconductor material such as silicon or gallium, a glass material such as Pyrex or silicon oxide, a polymer material such as polyimide or bakelite, and a metal material such as copper or aluminum are used. be able to. Similarly, the substrate electrode can be made of a known conductive material such as chromium, nickel, and aluminum. The substrate electrode insulating layer and the drive electrode insulating layer can also be made of a known insulating material such as silicon oxide, silicon nitride, and polyimide. When the substrate material is an insulating material such as a glass material or a polymer material, the substrate electrode insulating layer is not necessarily required.

The shapes of the drive electrodes are shown in FIGS.
The shape is not limited to a conical shape and a spiral shape as shown in FIG. 3, but may be a quadrangular pyramid shape as shown in FIG. 4 or a multi-pyramid shape as shown in FIG.

Although the embodiments of the present invention have been described above with reference to specific examples, the present invention is not limited to the above-described contents, and the present invention is not limited thereto. , Any deformation or change is possible.

[0021]

The electrostatic microactuator of the present invention can be driven in the vertical direction, and the point at which the driving force is generated does not change during driving. Therefore,
It suffices to use an electrostatic microactuator whose size is almost theoretically required for the object to be driven. For this reason, it is possible to reduce the size of an MO driving device or the like that requires an actuator.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a drive electrode is at a raised position in an example of a preferred embodiment of the electrostatic microactuator of the present invention.

FIG. 2 is a perspective view showing a state where a driving electrode is at a lowered position in an example of a preferred embodiment of the electrostatic microactuator of the present invention.

FIG. 3 is a perspective view showing another example of a preferred embodiment of the electrostatic microactuator of the present invention.

FIG. 4 is a plan view showing another example of the drive electrode in the electrostatic microactuator of the present invention.

FIG. 5 is a plan view showing another example of a drive electrode in the electrostatic microactuator of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 11 Substrate 2, 12 Substrate electrode insulating layer 3, Substrate electrode 4 Substrate electrode pad part 5, 15 Drive electrode insulating layer 7, 17 Drive electrode pad part 8, 18 Drive electrode 8A, 18A Mounting position of object to be driven 9 External power supply 10, 20 Electrostatic micro-actuator 13-1 First substrate electrode 13-2 Second substrate electrode 13-3 Third substrate electrode 13-4 Fourth substrate electrode 14-1 First substrate electrode pad Part 14-2 Second substrate electrode pad part 14-3 Third substrate electrode pad part 14-4 Fourth substrate electrode pad part 18-1 and 18-5 Part of drive electrode located on first substrate electrode 18-2, 18-6 Portion of Drive Electrode Positioned on Second Substrate Electrode 18-3 Portion of Drive Electrode Positioned on Third Substrate Electrode 18-4 Portion of Drive Electrode Positioned on Fourth Substrate Electrode A -A line, B- B-line center axis of spiral of drive electrode

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-6-339284 (JP, A) JP-A-5-318012 (JP, A) JP-A-7-240033 (JP, A) JP-A-9-99 126833 (JP, A) JP-A-9-237906 (JP, A) JP-A-8-129875 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B81B 3/00 G11B 7 / 09 H02N 1/00 G11B 11/105

Claims (5)

(57) [Claims] 1. A semiconductor device comprising a substrate, a substrate electrode insulating layer, a substrate electrode, a driving electrode insulating layer, and a driving electrode made of an amorphous alloy having a supercooled liquid region, and these are laminated in this order. The electrostatic microactuator, wherein the driving electrode has a spiral shape. 2. The electrostatic microactuator according to claim 1, wherein the substrate electrode is divided into a plurality. 3. The device according to claim 2, wherein the number of divisions of the substrate electrode is at least three times the overlapping number of the drive electrodes.
3. The electrostatic microactuator according to claim 1. 4. The electrostatic microactuator according to claim 3, wherein the number of divisions of the substrate electrode is 3 to 60 times the overlapping number of the drive electrodes. 5. The amorphous alloy comprises Zr—Cu—Al,
The electrostatic microactuator according to any one of claims 1 to 4, wherein the electrostatic microactuator is at least one selected from Pd-Cu-Si, Pd-Ni-P, and Au-Si.