JPH055693Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement of a mechanical resonator used as an acceleration sensor or the like.

BACKGROUND ART Conventionally, this type of mechanical resonator is usually constructed by vertically connecting metal resonators with thin metal connectors.

However, since the mechanical resonator is based on a metal piece, there is a limit to how small it can be made, and it also has the disadvantage that it is not possible to obtain homogeneous and stable vibration characteristics.

Problem to be solved by the invention The objective of the present invention is to provide a mechanical resonator that has stable vibration characteristics, is suitable for use as an acceleration sensor, etc., and can be made compact by applying semiconductor manufacturing processes.

Means for Solving the Problems In the mechanical resonator according to the present invention, an input signal is applied to a coil on the plane of the substrate, and resonance occurs due to the magnetic force line action between the input signal applying resonator and the input signal applying resonator. The output signal generating resonator is integrally formed from a single crystal such as silicon or sapphire, and generates an electrical output corresponding to the current induced in the coil on the plane of the substrate. A substrate portion that is a forming surface of the coil, a bridge portion that is relatively thinner than the substrate portion and extends laterally from the substrate portion, and a bridge portion that is relatively thicker than the substrate portion and extends laterally from the substrate portion. The input signal applying resonator has a coil forming surface positioned relative to the coil forming surface of the output signal generating resonator.
It is configured to be attached and fixed to the base of the output signal generating resonator.

Function In this mechanical resonator, when an input signal is applied to the coil formed on the substrate plane of the input signal application resonator, the output signal generation resonator resonates due to the magnetic field line action with the input signal application resonator. With the resonance, a current is induced in the coil of the output signal generating resonator located opposite the coil forming surface of the input signal applying resonator. In response to this current, the output signal generating resonator generates an electrical output, so if the electrical output is applied, it can be configured as an acceleration sensor or the like.

In this mechanical resonator, the resonator for generating the output signal is made of a material such as silicon or sapphire that has the inherent elasticity and rigidity of a single crystal, so it has uniform vibration characteristics and produces a stable electrical output. It can be configured as follows. In addition, since each part of the output signal generating resonator including the coil part can be formed using the single crystal by a semiconductor manufacturing process, the entire resonator can be formed into an extremely small size with excellent dimensional accuracy.

Embodiments The following description will be made with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, this mechanical resonator is comprised of three resonators A, A', and B in which thin film coils 1, 2, and 3 are formed on each substrate plane. Among them, the resonators A located above and below,
A' is based on glass substrates 4 and 5, and each coil 1,
2 on the surfaces of the glass substrates 4 and 5, it is configured for signal application to which an AC signal or a magnetic bias input signal is applied. In addition, the resonator B located in the middle is the signal applying resonator A,
It is configured as an output signal generating resonator that generates an electrical output according to the current induced in the coil 3 on the plane of the substrate as it resonates due to the magnetic force line action with A'. Input signal application resonators A and A' are integrally assembled with the output signal generation resonator B, with the surfaces on which the coils 1, 2, and 3 are formed facing each other.

In the output signal generating resonator B, all parts except the coil 3 are integrally molded using a single crystal material such as silicon or sapphire as a base. The output signal generating resonator B includes a substrate portion 6a that is a surface on which the coil 3 is formed, a bridge portion 6b that is relatively thinner than the substrate portion 6a and extends laterally from the substrate portion 6a, and a substrate portion 6a. The base portion 6c is relatively thicker than the portion 6a and supports the substrate portion 6a in a cantilevered manner via a bridging portion 6b.

Including these parts 6a, 6b, 6c and the coil 3, at least the output signal generation resonator B is the third
It can be manufactured through a semiconductor manufacturing process as shown in the figure. When this semiconductor manufacturing process is applied, first, as shown in FIG.
Form a concave groove with a thickness of . Next, figure b
As shown in , a film of a metal such as Al having good conductivity is formed by sputtering or the like on one side of the substrate portion 6a, and photo-etching is performed to form a spirally continuous coil 3 on the plane of the substrate portion 6a.
Thereafter, photoetching is performed again to form a bridge portion 6b thinner than the substrate portion 6a and a thicker base portion 6c as shown in FIG. Furthermore, as shown in FIG. 4D, by leaving the bridging part 6b and leaving the periphery as a gap, it is possible to form a vibrating part in which the substrate part 6a including the bridging part 6b is cantilevered by the base part 6c.
The bridging portion 6b and the base portion 6c are formed by sputtering a film of a metal with good conductivity similar to that described above, and by performing photoetching.
As shown in the figure e, the conductor parts 3a and 3b of the coil 3
In addition, external connection portions 3c and 3d are formed.

According to this semiconductor manufacturing process, not only can each element be formed into an ultra-small size of several millimeters square, but it can also be formed with high dimensional accuracy, with variations of less than 1 μm. In addition, since the output signal generating resonator B uses a single crystal material such as silicon or sapphire having uniform elasticity and rigidity as a base, and the substrate portion 6a, the bridge portion 6b, and the base portion 6c are integrally formed, the vibration characteristics can produce a homogeneous and stable electrical output, and can be manufactured efficiently through a series of steps. The remaining parts 7 of the above-mentioned parts 6a to 6c are such that the plate surface on which the coils 1 and 2 of the input signal applying resonators A and A' are formed is the substrate part 6a on which the coil 3 of the output signal generating resonator B is formed. By positioning the signal applying resonators A and A' relative to each other, the signal applying resonators A and A' can be used as a spacer section that spans and fixes the signal applying resonators A and A' to the base section 6c.

In addition, each of the above-mentioned parts 3, 6a to 6c can be formed by arranging a plurality of units in a single crystal body having a large area, and by dividing each unit after the fact, a plurality of units can be molded at the same time. Furthermore, by applying the semiconductor manufacturing process that includes the photo-etching process, sputtering process, and photo-etching process described above, it is also possible to form resonators A and A' for applying input signals using the glass substrates 4 and 5. The resonators A and A' for applying the input signal are arranged on a glass substrate with a large plane area to form coils 1 and 2, and then placed on the upper and lower sides of the undivided single crystal that constitutes the resonator B for generating the output signal. By stacking them together and gluing them together and cutting them in the vertical and horizontal directions, a plurality of units as shown in FIGS. 1 and 2 can be manufactured at the same time. In this case, the glass substrate may be photoetched in the final step to expose the external connection portions 3c and 3d led out from the coil 3 of the output signal generating resonator B to the outside.

The mechanical resonator configured in this way can be wound at either end of the coils 1 and 2 of the input signal application resonators A and A', or if the coils 1 and 2 are wound in the same rotation direction, they can be wound in series. An input signal can be applied to both ends of the coils 1 and 2 by connecting the coils to the coils 1 and 2.

When the mechanical resonator is applied as an acceleration sensor in the circuit shown in Fig. 4, when a magnetic bias is applied to the coil ends of the input signal application resonators A, A', the lines of magnetic force change between the signal application resonators A and A'. A current is generated in the coils 1 and 2 of the output signal generating resonator B, and a current is also induced in the coil 3 of the output signal generating resonator B, thereby generating lines of magnetic force. The magnetic lines of force generated from the coils 1 and 2 and the lines of magnetic force generated by the current induced in the coil 3 interact with each other as attraction and repulsion forces, and the output signal generation resonator B acts on the signal application resonators A and A'. By resonating with , the substrate portion 6a including the bridge portion 6b of the output signal generating resonator B starts to vibrate.

At the same time, when external mechanical vibration or fluctuating force is applied to the substrate section 6a including the bridge section 6b of the output signal generating resonator B, the number of magnetic fluxes penetrating the coil 3 changes, causing a current to flow through the coil 3. guided by
An electrical output I corresponding to external vibrations and acceleration components of fluctuating force can be obtained.

The electrical output is determined based on the mass of the substrate section 6a and the length of the bridge section 6b since the substrate section 6a including the bridge section 6b of the output signal generating resonator B is formed of a single crystal such as silicon or sapphire. It can be obtained as a stable product by having a unique resonant frequency. By applying this electrical output, it can function as an acceleration sensor with stable vibration characteristics.
Further, even if an alternating current signal having a constant frequency is applied to the coils 1 and 2, a similar output can be obtained.

Effects of the Invention As described above, according to the mechanical resonator of the present invention, at least the resonator that obtains an electrical output is formed using a single crystal such as silicon or sapphire as a base. Stable vibration characteristics can be obtained due to elasticity and rigidity, and since it can be formed using a semiconductor manufacturing process, it can be formed into an ultra-small size, and a resonator suitable for an acceleration sensor or the like can be configured.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a mechanical resonator according to the present invention, FIG. 2 is a side view of the resonator, and FIGS. 3 a to 3 are explanatory diagrams showing semiconductor manufacturing process steps for a resonator using a single crystal. FIG. 4 shows a circuit in which an acceleration sensor is constructed using a mechanical resonator according to the present invention. A, A'... Resonator for signal application, B... Resonator for output signal generation, 1, 2, 3... Coil, 6...
Single crystal material such as silicon or sapphire, 6a...substrate part, 6b...bridge part, 6c...base part.

Claims (1)

[Utility Model Claims] A mechanical resonator comprising: an input signal applying resonator in which an input signal is applied to a coil on a substrate plane; and an output signal generating resonator which generates an electrical output corresponding to a current induced in the coil on the substrate plane as a result of resonance due to the action of magnetic lines of force with the input signal applying resonator, wherein the output signal generating resonator comprises a substrate portion which serves as a coil forming surface formed integrally from a single crystal such as silicon or sapphire, a bridging portion which is relatively thinner than the substrate portion and extends laterally from the substrate portion, and a base portion which is relatively thicker than the substrate portion and cantilevers the substrate portion via the bridging portion, wherein the coil forming surface of the input signal applying resonator is positioned relative to the coil forming surface of the output signal generating resonator, and is attached and fixed to the base portion of the output signal generating resonator.