JPH04117176A - Electrostatic motor - Google Patents

Abstract

PURPOSE:To reduce the number of wirings to be led to bonding pads, etc., by stereoscopically crossing parts of wirings for applying a voltage to a stator electrode, and forming a gap between the stereoscopically crossing wirings. CONSTITUTION:A rotor 2, and stator electrodes 3a-3c are provided. The electrodes 3a-3c are alternately disposed on the outer periphery of the rotor 2, and wirings 4 connected to the electrodes 3a-3c are formed of annularly common coils 10a-10c, and individual wirings 11a-11c for connecting the electrodes 3a-3c of the same phase to the coils 10a-10c. Parts of the wirings 4 for applying a voltage to the electrodes 3a-3c are stereoscopically crossed, and a gap 5 is formed between the stereoscopically crossed wirings 4. Accordingly, the wirings 4 connected, for example, to the electrodes of the same phase can be integrated to one wiring 4. Thus, the number of the wirings 4 to be led to bonding pads can be reduced to the number equal to the lowest number of rotor electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a minute electrostatic motor manufactured by a semiconductor process.

[Background technology] Conventional electrostatic motor 3 manufactured by semiconductor process
1 is shown in FIGS. 5 and 6. This is an insulating film 3 such as a silicon oxide film on the surface of a semiconductor substrate 32 such as a silicon substrate.
A rotor 35 is rotatably supported by a shaft 34 fixed on an insulating film 33.
Four rotor electrodes 36 are formed radially.

On the other hand, 12 poles of stator electrodes 37a, 37b, and 37c are arranged around the outer periphery of the rotor electrode 36.
A plurality of wires 38 made of a conductive thin film formed on the surface of
are connected, and these wirings 38 are drawn out in parallel to, for example, a bonding pad so as not to contact each other.

Thus, a driving voltage is applied from the driver circuit through the wiring 38 to each of the three stator electrodes 37a, 37b, and 37c (for example, each stator electrode 37a) so that they are in phase, and the stator electrodes to which no driving voltage is applied ( for example,
37b, 37c) are grounded, and the stator electrodes to which the drive voltage is applied are sequentially switched, and the stator electrodes 37a, 37
b.

The rotor 35 is rotated by electrostatic attraction acting between the rotor electrode 37c and the rotor electrode 36.

Note that the rotor 35 may or may not be grounded.

[Problems to be Solved by the Invention] Electrostatic motors manufactured by semiconductor processes are characterized by being extremely small and capable of high rotation speeds. In this electrostatic motor, motor performance can be improved by increasing the number of stator electrodes. Increasing the number of stator electrodes itself only increases the number of divisions of the annularly arranged electrodes, so it does not affect the size of the electrostatic motor, but as the number of stator electrodes increases, the number of wiring increases accordingly. However, as will be explained below, there is a problem in that the increased wiring space impedes miniaturization of the electrostatic motor.

In other words, in an electrostatic motor manufactured using such a conventional semiconductor process, the same number of wires as the stator electrodes must be drawn out from the stator electrode, resulting in a large number of wires and a large wiring space. There was a problem.

Moreover, if the distance or interval between parallel wires is too small, the capacitance (stray capacitance) between the wires will increase, and a large voltage will be applied to the stator electrodes to which no driving voltage is applied through this capacitance. However, there was a problem in that the driving torque of the rotor was reduced. For this reason, it is difficult to wire each wiring in close proximity to each other, and it is not possible to increase the wiring room size.

Increasing the number of stator electrodes increases the number of wires, so under conditions where the number of wires is limited, it is possible to increase the number of stator electrodes, increase driving torque,
It was not possible to meet the demands for improved rotational accuracy and reduced torque ripple.

The present invention has been made in view of the drawbacks of the conventional example of slanting.The purpose of the present invention is to reduce the wiring space of the wiring connected to the stator electrode, and to reduce the wiring space of the wiring connected to the stator electrode. The objective is to improve the motor performance of the motor.

[Means for Solving the Problems] An electrostatic motor of the present invention includes a rotatable rotor having a rotor electrode and a plurality of stator electrodes for driving the rotor, and is manufactured by a semiconductor process. The present invention is characterized in that a portion of the wiring for applying voltage to the stator electrodes intersects three-dimensionally, and a gap is formed between the three-dimensionally intersected wirings.

Furthermore, an insulating layer and a gas layer or a vacuum layer may be laminated within the gap.

[Function] In the present invention, since the wires of the stator electrodes are crossed three-dimensionally through the gap, the wires connected to the stator electrodes having different phases among the wires connected to the stator electrodes are crossed. By doing so, the wires connected to the stator electrodes of the same phase can be combined into one wire. Therefore, for example, the number of wires drawn out to the bonding pad can be reduced to a number equal to the minimum number of rotor electrodes.

Furthermore, if an insulating layer and a gas layer or a vacuum layer are laminated in the gap as in the invention of claim 2, the capacitance between the wirings can be significantly reduced, so that the rotor can be driven. The distance or spacing between wires can be reduced without reducing torque, and the wire density can be increased.

As described above, the number of wires can be reduced compared to the number of stator electrodes, and the wiring density can be increased by bringing the wires closer together, so the wiring space for the electrostatic motor can be extremely reduced. , contributing to the miniaturization of electrostatic motors. Furthermore, since it becomes possible to provide a large number of stator electrodes without considering wiring space, driving torque increases, rotation accuracy improves, rotor rotation becomes smooth, and torque ripple is reduced.

[Example] Hereinafter, one embodiment of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 shows a plan view of an electrostatic motor A according to this embodiment. The rotor 2 has 16 rotor electrodes 1 arranged radially, and is rotatably supported by a shaft 9 fixed to the upper surface of the insulating layer 8 on the surface of the semiconductor substrate. The stator electrode has three types of phases (temporarily, this is human phase, B phase,
Let's call it phase C. ), and these three-phase stator electrodes 3a, 3b, and 3c are arranged alternately on the outer circumference of the rotor 2, and a total of 48 poles are provided in an annular shape on the outer circumference of the rotor 2. . Stator electrode 3a
, 3b, 3c, three annular common wire rings 10a, 10b, 10C, stator electrodes 3a+3b, 3c of the same phase, and common wire rings 10a, 1.
Individual wiring sections 11a, llb, l connecting 0b, 10C
The A-phase stator electrodes 3a are all connected to the inner common line 10a by individual wiring parts 11a, and the B-phase stator electrodes 3b are connected to the central common line by individual wiring parts 11b. connected to the ring 10b, C
The stator electrodes 3c of each phase are connected to the outer common wire ring 10c by individual wiring portions 11c. Therefore, the individual wiring parts (for example, 11a) connected to the stator electrodes (for example, 3a) of the same phase are connected to the common wire ring (for example, 1
0a), but wires connected to stator electrodes of different phases (for example, 3a and 3b, 3c) (for example, 10a and lla and 10b and 11
b, 10c and 11C) are three-dimensionally crossed so as not to contact each other. For example, FIG. 2 shows a portion where the C-phase individual wiring section lie and the A-phase and B-phase common wire rings 10a, 10b intersect three-dimensionally. In this way, at the intersection between the individual wiring section 11c and the common wire loops 10a and 10b of different phases, the individual wiring section lie is connected to the common wire loops 10a and 10b of different phases.
a, 10b to form a gap 5 between the individual wiring portion Llc and the common wire rings 10a, 10b of different phases. In this way, the individual wiring portions (for example, 11c) and the common wiring portions (for example, 10a, 10b) of different phases are connected.
By intersecting them three-dimensionally, all the individual wiring parts (for example, 11c) of the same phase can be connected to the common wire ring (10c) of the same phase, so that each common wire ring 10a, 10
Only three wires 4 are needed to be drawn out from b and 10c to, for example, a bonding pad. Therefore, the common line 10 a
.

LOb, 10c and individual wiring sections 11a, llb.

11c can be constructed compactly as shown in FIG.

The number of wires drawn out from 10c is determined by stator electrodes 3a and 3.
The number of electrodes can be extremely reduced compared to the numbers of electrodes b and 3c, and the wiring space can be significantly reduced.

In the electrostatic motor A, the rotor 2 is grounded, and as shown in FIG. ) A-phase stator electrode 3a →...
The rotation of the rotor 2 is maintained by applying the drive voltages in the order of...

If wires 4 of different phases are too close to each other, the stator electrodes 3a, 3 of different phases may
Noise is given to b and 3c.

For this reason, it is necessary to reduce the dielectric constant between the wires 4 of different phases to make the capacitance between both wires 4 as small as possible. Therefore, in this embodiment, as shown in FIG.
Common wire ring 10a, fob at the intersection with b, llc
, 10c are covered with an insulating layer θ, and the common wires 10a, 10b are
, 10c and the individual wiring sections 11a, llb, llc have a two-layer structure consisting of an insulator layer 6 and an air layer 7, thereby reducing the capacitance between the wirings 4. As an embodiment of the present invention, it is also possible to fill the gap 5 with an insulating layer 6, but as described above, the insulating layer 6 and the air layer 7 are
By forming a layered structure, the capacitance between the wirings 4 can be significantly reduced. Figures 4(a) and (b) show this 2
One example? FIG. 4(a) shows an example in which an insulator layer 6 having a dielectric constant εl is filled between wires 4 facing each other at a distance d, and the per unit area of the wire is The capacitance C1 of is expressed as C+=. On the other hand, FIG. 4(b) shows an insulator layer 6 with a dielectric constant ε1 and a thickness d2 between the wires 4 facing each other with a distance d, and an air layer 7 with a dielectric constant ε1 and a thickness d. This is an example in which the capacitance per unit area of the wiring is C
2 is expressed as C1·d1+ε1·d2. Here, ε1=8ε1, d□=d2=d
/2, C2 becomes 22% of C1, and the capacitance can be made extremely small.

In the above embodiment, the gap between the wirings was made up of an insulating layer and an air layer, but the gap may also be made up of an insulating layer and a vacuum layer, or an insulating layer. It may be composed of a layer and a nonflammable gas layer.

[Effects of the Invention] According to the present invention, the number of wires drawn out to, for example, a bonding pad or the like can be reduced. Furthermore, it becomes possible to increase wiring density. As a result, the wiring space for the electrostatic motor can be extremely reduced, contributing to miniaturization of the electrostatic motor. In addition, since it is possible to provide a large number of stator electrodes without requiring any wiring space, drive torque can be increased, rotor rotation can be made smoother by improving rotational accuracy, and torque ripple can also be reduced. can be done.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view showing the main part of an embodiment of the present invention, FIG. 2 is a plan view showing the entire same as above, FIG. 3 is a time chart showing the timing of applying drive voltage to the stator electrodes, and FIG. Figure 4 (a) and (b) are explanatory diagrams of the action of the gap part,
FIG. 5 is a plan view of the conventional example, and FIG. 6 is a sectional view showing a portion of the same. 1... Rotor electrode 2... Rotor 3a, 3b, 3cm, Stator electrode 4... Wiring 5... Gap 6... Insulator layer 7... Air layer

Claims (2)

[Claims] (1) In an electrostatic motor manufactured by a semiconductor process that includes a rotatable rotor having a rotor electrode and a plurality of stator electrodes for driving the rotor, a portion of wiring for applying voltage to the stator electrodes. An electrostatic motor characterized by intersecting three-dimensionally and forming a gap between the three-dimensionally intersecting wires. (2) The electrostatic motor according to claim 1, wherein an insulating layer and a gas layer or a vacuum layer are laminated within the gap.