CN202485670U - Micromechanical capacitive tilt sensor - Google Patents

Abstract

The utility model discloses a micromechanical capacitive inclination sensor which comprises a semiconductor chip and peripheral electrodes arranged on the semiconductor chip, a first semicircular electrode and a second semicircular electrode, a first semicircular electrode and a second semicircular electrode. The shaped electrodes are symmetrically arranged in the peripheral electrode; the groove between the peripheral electrode and the first semicircular electrode and the second semicircular electrode is filled with an insulating liquid medium, and the top of the peripheral electrode is provided with a seal for sealing the insulating liquid medium. A sealing device; the first semicircular electrode and the peripheral electrode form a first capacitor, and the second semicircular electrode and the peripheral electrode form a second capacitor symmetrical to the first capacitor. The first capacitance of the utility model is symmetrical to the second capacitance, and the capacitance is differentially output, the resolution is high and the influence of parasitic capacitance can be eliminated; the utility model has the advantages of small volume, simple process and high sensitivity.

Description

A Micromachined Capacitive Inclination Sensor

technical field

The utility model relates to an inclination sensor, in particular to a micromechanical capacitive inclination sensor. the

Background technique

Level sensors are widely used in various environments such as engineering, construction and laboratories. The traditional blister-type spirit level is divided into long blisters for measuring one-dimensional level errors and round blisters for measuring two-dimensional horizontal planes. One-dimensional structure measurement accuracy is high, but two-dimensional measurement requires two perpendicular to each other, which occupies a large volume and cannot realize an automatic measurement system. Two-dimensional measurement of circular blisters has poor precision and cannot be integrated with measurement circuits. the

The horizontal measurement realized by the inclination sensor is the main composition mode of the current measurement system. Traditional inclination sensors are bulky. Inclination sensors can be divided into three types: "solid pendulum", "liquid pendulum" and "gas pendulum" in terms of working principle, each of which has its own strengths. In the gravitational field, the sensitive mass of the solid pendulum is the pendulum mass, the sensitive mass of the liquid pendulum is the electrolyte, and the sensitive mass of the gas pendulum is the gas. The gas tilt sensor has strong anti-vibration or impact ability, but the gas movement control is more complicated, the manufacturing process is complicated, there are many factors affecting its movement, and its accuracy is difficult to improve. The solid pendulum inclination sensor has a definite pendulum length and pendulum center, and its mechanism is basically the same as that of the acceleration sensor. the

Utility model content

Aiming at the deficiencies in the prior art, the purpose of the utility model is to provide a micro-mechanical capacitive inclination sensor with small volume, simple manufacturing process and high sensitivity. the

In order to achieve the above object, the utility model is realized through the following technical solutions:

The utility model comprises a semiconductor chip and a peripheral electrode arranged on the semiconductor chip, a first semicircular electrode and a second semicircular electrode, and the first semicircular electrode and the second semicircular electrode are symmetrically arranged in the peripheral electrode; The groove between the electrode and the first semicircular electrode and the second semicircular electrode is filled with an insulating liquid medium, and a sealing device for sealing the insulating liquid medium is provided above the peripheral electrode; the first semicircular electrode and the second semicircular electrode The peripheral electrodes form a first capacitor, and the second semicircular electrodes and the peripheral electrodes form a second capacitor symmetrical to the first capacitor. Due to the symmetry and consistency of the first capacitor and the second capacitor, the capacitor differential output can effectively suppress the parasitic effect. the

The peripheral electrodes, the first semicircular electrodes and the second semicircular electrodes are respectively provided with peripheral electrode leads, first semicircular electrode leads and second semicircular electrode leads; the sealing device is provided with peripheral electrode lead holes , the first semicircular electrode lead hole and the second semicircular electrode lead hole; the peripheral electrode lead, the first semicircular electrode lead and the second semicircular electrode lead respectively pass through the peripheral electrode lead hole, the first semicircular electrode lead The electrode lead hole and the second semicircular electrode lead hole are connected with the external capacitance detection device. the

The above-mentioned peripheral electrodes are waist-shaped. The capacitor plates are all semicircular, so the difference between the first capacitor and the second capacitor and the size of the inclination angle change approximately linearly within a dumping angle close to 90 degrees. the

The above-mentioned semiconductor wafers are SOI silicon wafers. The use of SOI silicon wafers is because the electrodes of the capacitor formed by the peripheral electrodes, the first semicircular electrodes and the second semicircular electrodes must be insulated from each other, so there must be a support before packaging. Using SOI can solve this problem. SOI silicon wafers are called It is silicon on insulator, its structure is silicon/insulator/silicon, and it is a commercial material. The utility model is made on the first layer of silicon, the middle insulator is used as isolation, and the back silicon is used as support. the

The above-mentioned sealing device adopts a glass plate or an organic substrate. the

The first capacitance of the utility model is symmetrical to the second capacitance, and the capacitance is differentially output, the resolution is high and the influence of parasitic capacitance can be eliminated; the utility model has the advantages of small volume, simple process and high sensitivity. the

Description of drawings

Fig. 1 is the structural representation of the utility model. the

Each label in the figure: semiconductor chip 1, peripheral electrode 2, first semicircular electrode 3, second semicircular electrode 4, insulating liquid medium 5, groove 6. the

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the utility model easy to understand, the utility model will be further elaborated below in conjunction with specific embodiments. the

Referring to FIG. 1 , the utility model includes a semiconductor chip 1 and a waist-shaped peripheral electrode 2 , a first semicircular electrode 3 and a second semicircular electrode 4 arranged on the semiconductor chip 1 . the

Wherein, the first semicircular electrode 3 and the second semicircular electrode 4 are symmetrically arranged in the peripheral electrode 2 . the

In the groove 6 between the peripheral electrode 2 and the first semicircular electrode 3 and the second semicircular electrode 4, a small amount of insulating liquid medium 5 with a larger dielectric constant is filled, and a device for insulation is installed above the peripheral electrode 2. A sealing device (not shown in the figure) for sealing the liquid medium 5 . the

Wherein, the first semicircular electrode 3 and the peripheral electrode 2 form a semicircular first capacitor, and the second semicircular electrode 4 and the peripheral electrode 2 form a semicircular second capacitor symmetrical to the first capacitor (this embodiment Among them, the shape of the peripheral electrode 2 is waist-shaped, and the semicircular shapes on the left and right sides of the peripheral electrode 2 are respectively connected with the semicircular shape of the first semicircular electrode 3 and the semicircular shape of the second semicircular electrode 4. Consistent, thus forming two semicircular capacitors). the

The peripheral electrode 2, the first semicircular electrode 3 and the second semicircular electrode 4 are of the same material, separated by one etching, which ensures the symmetry and consistency of the first capacitor and the second capacitor composed of the above materials . Due to the symmetry and consistency of the first capacitor and the second capacitor, the resolution of the capacitor differential output is high and the parasitic effect can be effectively suppressed. the

On the peripheral electrode 2, the first semicircular electrode 3 and the second semicircular electrode 4, there are respectively engraved peripheral electrode leads (not shown in the figure), first semicircular electrode leads (not shown in the figure) and The second semicircular electrode leads (not shown in the figure). the

A peripheral electrode lead hole (not shown in the figure), a first semicircular electrode lead hole (not shown in the figure) and a second semicircular electrode lead hole (not shown in the figure) are chiseled on the sealing device. the

The peripheral electrode lead wires, the first semicircular electrode lead wires and the second semicircular electrode lead wires respectively pass through the peripheral electrode lead wire holes, the first semicircular electrode lead wire holes and the second semicircular electrode lead wire holes to communicate with the external capacitance detection device. connect. the

In this embodiment, the semiconductor chip 1 is an SOI silicon chip; the sealing device is a glass plate or an organic substrate. the

Working process and principle of the present utility model are as follows:

In operation, if the sensor of the present invention is placed vertically, the insulating liquid medium 5 will flow to the bottom of the groove 6 . the

When there is an inclination in the system, the insulating liquid medium 5 will flow to the inclined side, the insulating liquid medium 5 in the capacitor on the inclined side will increase, and the insulating liquid medium 5 on the other side will decrease (the first capacitor and the second capacitor are filled The amount of insulating liquid medium 5 is just different). the

Because the dielectric constant of the insulating liquid medium 5 is much greater than that of air, the size of the first capacitance and the second capacitance is mainly determined by the length of a section of capacitance gap filled by the insulating liquid medium 5 (the difference between the first capacitance and the second capacitance and the inclination angle The greater the difference, the greater the inclination). the

By measuring the capacitance of the first capacitor and the capacitance of the second capacitor, the capacitance difference can be obtained, and then the angle of inclination can be reflected by a conventional calibration method. the

In this embodiment, since the capacitor plates are all semicircular, the difference between the first capacitor and the second capacitor and the inclination angle vary approximately linearly within a dumping angle of approximately 90 degrees. the

The utility model forms two symmetrical capacitors by carving grooves 6 once on the silicon chip, and the manufacturing process is simple. The change in the filling quantity of the insulating liquid medium 5 within a certain range only changes the size of the initial capacitor and does not affect the capacitance difference. Therefore, the sensor of the utility model has high sensitivity, good linearity and stability. the

The manufacturing process of the present utility model is as follows:

First of all, select an SOI silicon wafer, the surface silicon material is required to be low-doped, and the thickness is determined according to the designed capacitor structure, generally as thick as possible. the

Then, the silicon material on the surface is photolithographically etched, and the material is etched by an anisotropic etching process (such as deep reactive ion etching, etc.) until the interface stops when the silicon is oxidized, forming a structure as shown in Figure 1. the

Next, oxidize the entire silicon wafer, and then respectively open the peripheral electrode lead, the first semicircular electrode lead and the second semicircular electrode lead on the peripheral electrode 2, the first semicircular electrode 3 and the second semicircular electrode 4 by photolithography. Round electrode leads. the

Finally, fill the insulating liquid medium 5, and seal the peripheral electrode 2 with a glass plate, and open the peripheral electrode lead hole, the first semicircular electrode lead hole and the second semicircular electrode lead hole on the glass plate. the

The basic principles and main features of the present utility model and the advantages of the present utility model have been shown and described above. Those skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model The new model also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection required by the utility model is defined by the appended claims and their equivalents. the

Claims (5)

1. micro-mechanical capacitance type obliquity sensor; It is characterized in that; Comprise semiconductor chip (1) and be arranged on peripheral electrode (2), first semicircular electrode (3) and second semicircular electrode (4) on the semiconductor chip (1), said first semicircular electrode (3) and second semicircular electrode (4) are symmetricly set in the peripheral electrode (2);

Be filled with iknsulating liquid medium (5) in the groove (6) between said peripheral electrode (2) and first semicircular electrode (3) and second semicircular electrode (4), the top of peripheral electrode (2) is provided with and is used for packoff that iknsulating liquid medium (5) is sealed;

Said first semicircular electrode (3) is formed first electric capacity with peripheral electrode (2), said second semicircular electrode (4) and second electric capacity of peripheral electrode (2) composition with first electric capacity symmetry.

2. micro-mechanical capacitance type obliquity sensor according to claim 1 is characterized in that,

Be respectively equipped with peripheral electrode lead-in wire, first semicircular electrode lead-in wire and second semicircular electrode lead-in wire on said peripheral electrode (2), first semicircular electrode (3) and second semicircular electrode (4);

Said packoff is provided with peripheral electrode fairlead, the first semicircular electrode fairlead and the second semicircular electrode fairlead;

Said peripheral electrode lead-in wire, first semicircular electrode lead-in wire and second semicircular electrode lead-in wire run through peripheral electrode fairlead, the first semicircular electrode fairlead and the second semicircular electrode fairlead respectively and are connected with external capacitive size detection device.

3. micro-mechanical capacitance type obliquity sensor according to claim 1 and 2 is characterized in that, the waist type that is shaped as of said peripheral electrode (2).

4. micro-mechanical capacitance type obliquity sensor according to claim 1 and 2 is characterized in that, what said semiconductor chip (1) adopted is soi wafer.

5. micro-mechanical capacitance type obliquity sensor according to claim 1 and 2 is characterized in that, what said packoff adopted is glass plate or organic substrate.

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