JP3405108B2 - External force measuring device and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external force measuring apparatus suitable for measuring an external force (inertial force) acting on an object, such as acceleration and angular velocity, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, an external force measuring device is used for an acceleration measuring device, an angular velocity measuring device, etc. for detecting acceleration and angular velocity of a vehicle, camera shake of a camera and the like.

18 to 27, an acceleration measuring device will be described as an example of a conventional external force measuring device.

In the figure, reference numeral 1 is an acceleration measuring device produced by a micromachining technique, and 2 is a substrate made of, for example, a high resistance single crystal silicon plate so as to form the main body of the acceleration measuring device 1. A detection unit 3 and a lid 12 that covers the detection unit 3, which will be described later, are formed on the surface 2.

Reference numeral 3 denotes a detection portion formed on the substrate 2,
The detection unit 3 is formed, for example, by subjecting a low resistance silicon film to an etching process. The detecting section 3 is generally composed of fixed sections 4 and 4 located on the left and right sides of the substrate 2 and a movable section 6 which will be described later and is arranged between the fixed sections 4 and 4.

Here, the fixed portions 4 are provided on the substrate 2 so as to be spaced apart from each other on the left and right sides, and fixed side comb-shaped electrodes having five thin electrode plates 5A on inner surfaces facing each other. Projections 5 and 5 are formed.

Reference numeral 6 denotes a movable portion, which is the substrate 2
Support parts 7, 7 spaced apart from each other on the front and rear sides, a mass part 9 supported by each of the support parts 7 through a beam 8 and arranged between the fixed parts 4, and It is configured by integrally forming movable side comb-shaped electrodes 10, 10 having five thin plate-shaped electrode plates 10A protruding from the mass portion 9 in the left and right directions.

Further, since the movable portion 6 is formed by etching the sacrificial layer, the supporting portions 7 and 7 are formed on the substrate 2.
The beam 8 and the mass portion 9 are fixed to the upper portion, and are separated from the substrate 2 in the height direction.

Reference numeral 11 denotes a frame portion made of low resistance silicon (for example, polysilicon) like the detection portion 3, and the frame portion 11 is provided on the substrate 2 so as to surround the detection portion 3.

Reference numeral 12 denotes a lid body formed of a glass substrate. The lid body 12 is provided on the substrate 2 so as to cover the detection portion 3. The lid body 12 has a central portion on the lower surface to be described later. A recess 23 is formed. Further, by forming the recessed portion 23, a cutting partition wall 13 is formed so as to surround the recessed portion 23, and the front end surface of the cutting partition wall 13 is fixed to the fixing portion 4 of the detecting unit 3.
It becomes a joining surface 13A for anodic joining with the supporting portion 7 of the movable portion 6 and the frame portion 11.

The cutting partition wall 13 is a partition wall 2 which will be described later.
It is obtained by cutting 4 in half.
Then, the lid body 12 is anodically bonded to the fixed portion 4 of the detection portion 3, the support portion 7 of the movable portion 6, and the frame portion 11 to define a closed space 14 between the substrate 2 and the lid body 12, The detection unit 3 formed on the substrate 2 is housed in the closed space 14.

Reference numeral 15 denotes a through hole penetrating the lid body 12. The through hole 15 is formed at a portion corresponding to the fixing portion 4 and the supporting portion 7 of the detecting portion 3 of the lid body 12, and the through hole is formed. The hole 15 is filled with a conductive paste 16 containing silver or the like as a main component. Therefore, the through-hole 15 and the conductive paste 16 are attached to the detection unit 3
And a signal processing circuit (not shown) provided outside functions as a connection path for electrically connecting.

Next, a method of manufacturing the acceleration measuring device 1 will be described with reference to FIGS.

First, reference numeral 21 in FIG. 20 is a silicon wafer made of high-resistance single crystal silicon. The silicon wafer 21 has, for example, a diameter of 7.5 to 15.5 cm and a thickness of 500.
It is formed in a disk shape of about μm. An orientation flat 21A as shown in FIG. 22 is formed around the silicon wafer 21.

In the detection portion forming step shown in FIG. 21, a plurality of detection portions 3 are formed by etching a silicon after forming a low resistance silicon film on the silicon wafer 21, and each detection portion is formed. As shown in FIG. 22, 52, for example, 3 are formed on the silicon wafer 21 at predetermined intervals. At this time, at the same time, the frame portion 11 is formed on the silicon wafer 21 so as to surround each detection portion 3.

On the other hand, reference numeral 22 in FIG. 23 is a glass plate forming the lid body 11, and an orientation flat 22A as shown in FIG. 25 is formed around the glass plate 22.

In the lid forming step shown in FIG. 24, a large number (for example, 52 pieces) is formed on the lower surface of the glass plate 22 by etching.
The individual concave portions 23 are formed in a grid pattern. As a result, partition walls 24 are formed between the recessed portions 23, and the front end surface of the partition walls 24 serves as a bonding surface 24A with the silicon wafer 21 (FIG. 2).
5). Further, the through holes 15 are formed by sandblasting, etching, laser or the like. Then, each recess 23 forms the closed space 14 by bonding the glass plate 22 to the silicon wafer 21.

In the normal bonding step shown in FIG. 26, the silicon wafer 21 and the glass plate 22 are anodically bonded (the substrate temperature is 350 ° C. and the applied voltage is 1000 V) in a vacuum atmosphere, so that the silicon wafer 21 and the glass plate 22 are bonded together. And the inside of the closed space 14 formed by the joining are decompressed. At this time, the silicon wafer 21 and the glass plate 22
Aligns with the alignment patterns as shown by “◯” and “x” in FIGS. 22 and 25.

FIG. 27 shows a plurality of acceleration measuring devices 1 formed by a disk-shaped silicon wafer 21 and a glass plate 22 bonded by the above-mentioned bonding process.
By cutting the silicon wafer 21 and the glass plate 22 at the position of the partition wall 24 indicated by the chain double-dashed line, a plurality of acceleration measuring devices 1 can be manufactured at one time (cutting step).

Finally, a conductive paste 16 containing silver or the like as a main component is filled in the through holes 15, and the conductive paste 16 is electrically connected to the fixing portion 4 and the supporting portion 7.

In the acceleration measuring device 1 of the prior art constructed as described above, when an external acceleration is applied in the arrow A direction as shown in FIG. 18, the beam 8 is deformed and the mass portion 9 is moved in the arrow A direction. Is displaced to. At this time, the electrode plates 10A of the movable side comb-shaped electrodes 10, 10 of the mass portion 8 are fixed to the fixed side comb-shaped electrodes 5, 10.
Since the electrode plates 5A and 5A approach or separate from each other, the displacement of the distance between the opposing electrode plates 10A and 5A is output to an external signal processing circuit (not shown) as a change in capacitance. Then, the signal processing circuit outputs a signal corresponding to the acceleration based on the change in the electrostatic capacitance.

Further, in this acceleration measuring apparatus 1, each electrode plate 10A of the movable side comb-shaped electrode 10 and the fixed side comb-shaped electrode 5 are provided.
The acceleration is detected by the electrostatic capacity between each of the electrode plates 5A and 5A, and the electrode plates 10A and 5A are electrically connected in parallel.
And the electrostatic capacitance between 5A have an added value, and the detection sensitivity can be increased.

Further, in the acceleration measuring device 1, since the structure is fine, the influence of damping is great in the atmosphere, and the mass portion 9 does not have good responsiveness to acceleration. Therefore, in the acceleration measuring device 1, the air resistance to the mass portion 9 is reduced by reducing the pressure in the closed space 14 in which the detection portion 3 is housed, and the response to acceleration is improved to improve the detection accuracy. .

[0024]

By the way, in the acceleration measuring device 1 according to the above-mentioned conventional technique, as described above, the silicon wafer 21 having a plurality of detecting portions 3 formed on the surface thereof is used.
And the glass plate 22 having a large number of recesses 23 formed therein are configured to be anodically bonded in a vacuum atmosphere.
Therefore, when the silicon wafer 21 and the glass plate 22 are abutted against each other and pressure is applied to apply electricity to start bonding, oxygen gas is generated from the glass plate 22.

However, as shown in FIGS. 28 and 29, since the bonding surfaces 24A of all the partition walls 24 are not bonded to the silicon wafer 21 at the same time, the oxygen gas generated from the glass plate 22 flows as indicated by the arrow. , Remains in the sealed space 14 surrounded by the joint surface 24A that is finally joined.

Therefore, in the acceleration measuring device 1 according to the prior art, it is not possible to bring the sealed space 14 of all manufactured acceleration measuring devices 1 into an ideal depressurized state, and the sealed space 14 is depressurized. If it is not, the air resistance applied to the mass part 9 becomes large and the response of the acceleration deteriorates,
There is a problem that the detection sensitivity is lowered.

Further, since the acceleration measuring apparatus 1 manufactured as described above is manufactured in plural at a time by the silicon wafer 21 and the glass plate 22, depending on the position of the silicon wafer 21, oxygen in the closed space 14 may be generated. The gas efficiently discharged and the gas in which the oxygen gas is enclosed in the closed space 14 are mixed together to be manufactured. As a result, in each manufactured acceleration measuring device 1, there is a problem in that the pressure in the sealed space 14 is different, and there is a variation between a good product and a defective product, resulting in poor yield.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention discharges oxygen gas generated when anodic bonding a silicon plate and a glass plate from the inside of the closed space, It is an object of the present invention to provide an external force measuring device and a manufacturing method thereof that can reduce the pressure of the external force and increase the detection accuracy of the external force in the detection unit.

[0029]

In order to solve the above-mentioned problems, the invention of claim 1 provides a silicon plate, a glass plate provided by anodic bonding to the silicon plate in a reduced pressure atmosphere, and the silicon. A closed space defined between the silicon plate and the glass plate when the plate and the glass plate are joined,
A detection unit which is located on the silicon plate and which is provided in the closed space and detects a force applied from the outside, and a bonding surface of at least one of the silicon plate and the glass plate.
An outer space provided with a communication groove that surrounds the closed space in a state of being separated from the closed space and that communicates with the outside.
The force measuring device, wherein the communication groove is in the reduced pressure atmosphere.
Space where the closed space is formed when anodic bonding
The gas generated inside the gap between the silicon plate and the glass plate
To the outside, and the anodic bonding in the reduced pressure atmosphere
When finished it is characterized in that between the sealed space is cut off.

The gap With such a configuration, the communication groove is kept constantly reduced pressure communicates with the outside even when anodic bonding Rutotomoni communication grooves and the silicon plate and the glass plate
Since it is communicated with the space in which the closed space is formed through the, the gas generated at the time of joining is discharged to the outside through the communication groove located around the closed space, and the inside of the closed space can be depressurized. In addition, the anodic bonding in a reduced pressure atmosphere was completed.
The contact surface between the silicon plate and the glass plate
Since the closed space and the communication groove are blocked,
Even when taken out from the pressure atmosphere, the pressure inside the closed space is reduced.
Can be held.

According to a second aspect of the invention, the closed space is formed by closing a concave portion formed by surrounding a glass plate with a partition wall with a silicon plate, and a communication groove is provided on the joint surface at the tip of the partition wall.

With this structure, the communication groove formed on the bonding surface at the tip of the partition wall formed on the glass plate communicates with the outside even when performing anodic bonding and is always kept in a reduced pressure state. The generated gas can be discharged to the outside through the communication groove, and the inside of the sealed space can be depressurized.

According to the third aspect of the present invention, the closed space is formed by closing the concave portion formed by surrounding the glass plate with the partition wall with the silicon plate, and the communication groove is formed on the silicon plate.
In addition, it is provided at the portion where the joint surface at the tip of the partition wall is joined.

With this structure, the communication groove formed at the site where the bonding surface of the silicon plate is bonded is communicated with the outside even during anodic bonding and is always kept in a reduced pressure state. The generated gas can be discharged to the outside through the communication groove, and the inside of the closed space can be depressurized.

According to a fourth aspect of the present invention, a silicon plate, a glass plate provided by anodic bonding to the silicon plate in a reduced pressure atmosphere, and the silicon plate and the glass plate when the silicon plate and the glass plate are bonded together A method for manufacturing an external force measuring device, comprising: a closed space defined between a plate and a detection part, which is located on the silicon plate and is provided in the closed space to detect a force applied from the outside. A communication groove forming step of forming a communication groove communicating with the outside on a bonding surface of at least one of a silicon wafer forming the silicon plate and a glass plate; and a detection unit forming a detection unit on the silicon wafer. Forming step, and the silicon plate and the glass plate
Sky of the gap and the communicating said through Ji said sealed space to the groove in a state in which communication with the external silicon wafer and a glass plate by anodic bonding in a vacuum atmosphere, the sealed space is formed
The gas generated in the space is discharged to the outside through the communication groove,
When the anodic bonding is completed in a reduced pressure atmosphere, the above-mentioned sealing is performed.
And a joining step in which the space and the communication groove are shut off from each other.

[0036] With this configuration, even when anodically bonding a silicon wafer and a glass plate in a reduced pressure atmosphere in the bonding step, the communication groove is kept constantly reduced pressure communicates with the outside Rutotomoni communication groove Is a silicon plate and glass
Since the sealed space is communicated with the space through the gap with the plate, the gas generated at the time of joining is discharged to the outside through the communication groove located around the sealed space, Can be joined under reduced pressure. In addition, a reduced pressure atmosphere
When the anodic bonding in the atmosphere is completed, connect with the closed space.
It was taken out of the decompressed atmosphere because it was cut off from the passage.
Even in a closed space, it is possible to maintain a reduced pressure.
It

According to the fifth aspect of the invention, after the joining step, there is provided a cutting step of cutting the silicon wafer and the glass plate at the position of the partition wall in units of the closed space.

With this structure, it is possible to manufacture a plurality of external force measuring devices in which the sealed space is decompressed by joining the silicon wafer and the glass plate and then cutting at the position of the partition wall.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 17 of the accompanying drawings.
In the embodiments, the same components as those of the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

First, a first embodiment of the present invention will be described with reference to FIGS. 1 to 9. Reference numeral 31 is an acceleration measuring device which is an external force measuring device according to the present embodiment.
1 is almost the same as the acceleration measuring device 1 according to the prior art,
A substrate 2 made of high-resistance single crystal silicon, a detection unit 3 formed on the substrate 2, and the substrate 2 covering the detection unit 3.
It is composed of a lid 32 which will be described later and is anodically bonded.

Reference numeral 32 denotes a lid body formed of a glass plate, the lid body 32 is provided on the substrate 2 so as to cover the detection unit 3, and the lid body 32 is a lower surface of a glass plate 41 described later. It is configured by forming a concave portion 42 in the.

Reference numeral 33 denotes a closed space whose inside is depressurized,
The closed space 33 is formed between the substrate 2 and the lid 32, and the detection unit 3 formed on the substrate 2 is housed in the closed space 33.

Here, the lid 32 is surrounded by a cutting partition wall 34 whose front end surface is a bonding surface 34A, and the cutting partition wall 34 is anodically bonded to the fixing portion 4 of the detecting section 3. By joining to the support portion 7 and the frame portion 11,
A closed space 33 is defined between the lid 32 and the substrate 2.
The cutting partition wall 34 is obtained by cutting a partition wall 43 described later in half.

Reference numeral 35 denotes a notch as a communication groove formed on the outer periphery of the partition wall 34 of the lid 32. The notch 35 surrounds the closed space 33 in a state of being separated from the closed space 33. Has been formed. The cutout 35
Is formed as a communication groove 44 in the manufacturing process described later.

Reference numeral 36 denotes a through hole penetrating the lid body 12. The through hole 36 is formed at a portion corresponding to the fixed portion 4 and the support portion 7 of the detection portion 3 of the lid body 32, and the through hole 36 is formed. The hole 36 is filled with a conductive paste 37 containing silver as a main component, for example. Therefore, the through-hole 36 and the conductive paste 37 are attached to the detection unit 3
And a signal processing circuit (not shown) provided outside functions as a connection path for electrically connecting.

Next, a method of manufacturing the acceleration measuring device 31 will be described with reference to FIGS.

First, reference numeral 41 in FIG. 2 is a glass plate forming the lid 32, and an orientation flat (not shown) is formed on the glass plate 41 like the glass plate 22 described in the prior art. There is.

In the lid forming step shown in FIG. 3, the glass plate 4 is
A large number of concave portions 42 are formed in a grid pattern on the lower surface of 1 by etching. As a result, partition walls 43 are formed between the recessed portions 42, and the tip surface of the partition wall 43 has a silicon wafer 2
It becomes the joint surface 43A with 1. Then, each recess 42
The glass plate 41 is bonded to the silicon wafer 21 on which the detector 3 is formed to form the closed space 33.
Further, the through holes 36 are formed by sandblasting, etching, laser or the like.

In the communicating groove forming step shown in FIGS. 4 and 5, the joining surface 4 at the tip of the partition wall 43 extending in a grid pattern on the glass plate 41.
A communication groove 44 that surrounds the recess 42 and communicates with the outside is formed in 3A by etching.

Further, in the normal joining step shown in FIG. 6, the fixing portion 4, the support portion 7, the frame portion 11 and the glass plate 41 of the detecting portion 3 are anodically joined in a vacuum atmosphere (at a substrate temperature of 350).
The temperature is reduced to 1,000 V and the applied voltage is set to 1000 V) to bond them and reduce the pressure in the sealed space 33 formed between the silicon wafer 21 and the glass plate 41.

FIG. 7 shows a plurality of acceleration measuring devices 31 formed by a disk-shaped silicon wafer 21 and a glass plate 41 bonded by the above-described bonding process.
A plurality of acceleration measuring devices 31 can be manufactured by cutting the silicon wafer 21 and the glass plate 41 at the position of the partition wall 43 indicated by the chain double-dashed line (cutting step).

Finally, a conductive paste 37 containing silver or the like as a main component is filled in the through holes 36, and the conductive paste 37 is electrically connected to the fixing portion 4 and the supporting portion 7.

Also in the acceleration measuring apparatus 31 of this embodiment manufactured as described above, there is no particular difference from the acceleration measuring apparatus 1 according to the prior art in the operation of detecting the acceleration applied in the arrow A direction.

Therefore, the acceleration measuring device 3 according to the present embodiment.
In 1, the glass plate 41, the fixed portion 4, the support portion 7, the frame portion 11
Before joining and, a communicating groove 44 that surrounds the recessed portion 42 and communicates with the outside is formed in the joining surface 43A located at the tip of the partition wall 43 of the glass plate 41. As a result, the communicating groove 44 communicates with the surroundings having a high degree of vacuum and is always kept in a reduced pressure state even during anodic bonding.
The air in 2 and the oxygen gas generated from the glass plate 41 at the time of joining are discharged to the outside through the communication groove 44, so that the sealed space 33 can be depressurized.

Therefore, as shown in FIGS. 8 and 9, the oxygen gas generated from the glass plate 41 is sucked to the surroundings through the communication groove 44 formed so as to surround the recess 42 as shown by the arrow. Therefore, even when the bonding surfaces 43A of all the partition walls 43 are not bonded to the silicon wafer 21 at the same time, it is possible to prevent the oxygen gas generated from the glass plate 41 from remaining in the sealed space 33 that is bonded last. .

As a result, in the acceleration measuring device 31 according to the present embodiment, the inside of the closed space 33 can be put into an ideal depressurized state, and the air resistance applied to the mass portion 9 of the detecting portion 3 is reduced to detect the acceleration. The sensitivity can be increased.

Further, although the acceleration measuring device 31 is configured to manufacture a plurality of silicon wafers 21 and the glass plate 41 at a time, the communicating groove 44 can be formed at any position of the glass plate 41. Since the suction operation by the same works equally, it is possible to obtain the same depressurized state in the closed space 33 at any position, and the acceleration measuring device 3 at the time of manufacturing.
The number of defective products of No. 1 can be reduced and the yield can be increased.

Next, a second embodiment according to the present invention will be described with reference to FIGS. 10 to 17. The feature of this embodiment is that the communication groove is formed on the side of the substrate made of a silicon material. In this embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 51 denotes an acceleration measuring device which is an external force measuring device according to this embodiment.
Is substantially the same as the acceleration measuring device 1 according to the related art, and the substrate 52 made of high-resistance single crystal silicon and the substrate 52
The detection unit 3 is formed on the upper side, and the lid 12 is anodically bonded on the substrate 2 so as to cover the detection unit 3. The detection unit 3 includes a substrate 52 and a recess 23 of the lid 12. It is housed in a closed space 53 formed between the two.

Reference numeral 54 denotes a frame portion made of low resistance silicon (for example, polysilicon) like the detection portion 3, and the frame portion 54 is provided on the substrate 52 so as to surround the detection portion 3.

Reference numeral 55 denotes a notch as a communication groove formed on the outer periphery of the frame 54, the notch 55 being located on the side of the frame 54 and of the cutting partition wall 13 of the lid 12. The joining surface 13A located at the tip is formed at a portion to be joined, and surrounds the sealed space 53 in a state of being separated from the sealed space 53.

Next, a method of manufacturing the acceleration measuring device 51 will be described with reference to FIGS.

First, reference numeral 61 in FIG. 11 is a silicon wafer made of single-crystal, high-resistance single-crystal silicon. Is formed in.

In the step of forming the detecting portion and the step of forming the communicating groove shown in FIG. 12, after forming a low resistance silicon film on the silicon wafer 61, a plurality of detecting portions 3 are formed by etching the silicon. At this time, at the same time, a frame portion 54 is formed on the silicon wafer 61 so as to surround each of the detection portions 3, and a communication groove 62 is formed so as to penetrate to the silicon wafer 61 in the substantially central portion of the frame portion 54. ing.
Then, the frame portion 54 has a shape divided into two by the communication groove 62. The cutting position in the cutting step described below is substantially the center of the communication groove 62 (two-dot chain line in FIG. 15).
Becomes

Further, in the normal bonding step shown in FIG. 14, the silicon wafer 61, the fixed part 4 of the detection part 3 and the support part 7 of the movable part 6 are anodically bonded in a vacuum atmosphere (at a substrate temperature of 3).
The bonding is performed at 50 ° C. and an applied voltage of 1000 V), and the sealed space 53 that houses the detection unit 3 is depressurized between the silicon wafer 61 and the glass plate 22.

FIG. 15 shows a plurality of acceleration measuring devices 51 formed by a disc-shaped silicon wafer 61 and a glass plate 22 which are joined by the above-mentioned joining process. The silicon wafer 61 and the glass plate 22 are separated from each other. By cutting at the position of the chain double-dashed line, a plurality of acceleration measuring devices 51
Can be manufactured.

Finally, a conductive paste 16 containing silver or the like as a main component is filled in the through holes 15, and the conductive paste 16 is electrically connected to the fixing portion 4 and the supporting portion 7.

In the acceleration measuring apparatus 51 of the present embodiment manufactured in this way, the operation of detecting the acceleration applied in the direction of arrow A is not significantly different from the acceleration measuring apparatus 1 according to the prior art.

Therefore, the acceleration measuring device 5 according to the present embodiment.
Also in the first embodiment, as in the first embodiment described above, FIG.
17, the oxygen gas generated from the glass plate 22 at the time of bonding is sucked to the surroundings through the communication groove 62 formed so as to surround the recessed portion 23 as shown by the arrow, so that all the oxygen gas is absorbed. Even when the bonding surface 24A is not bonded to the silicon wafer 61 at the same time, it is possible to prevent the oxygen gas generated from the glass plate 22 from remaining in the sealed space 53 that is finally bonded.

As a result, the acceleration measuring device 51 according to the present embodiment can bring the inside of the closed space 53 into an ideal depressurized state, reduce the air resistance applied to the mass portion 9 of the detecting portion 3 and respond to acceleration. And the detection sensitivity can be improved.

In each embodiment, the acceleration measuring device 3
Although the communication grooves 44 and 62 are left as the notches 35 and 55 in the Nos. 1 and 51, the communication grooves 44 and 62 may be cut off at the time of cutting to eliminate the notches 35 and 55.
Furthermore, in the second embodiment, the communication groove 62 is formed by penetrating the central portion of the frame portion 54, but it may be formed as a recess on the upper surface of the frame portion 54.

Further, the communication grooves 44, 6 in each embodiment.
In the case of No. 2, the larger the cross-sectional area, the more easily oxygen is discharged to the outside, so that the pressure in the sealed spaces 33 and 53 can be further reduced.

In each of the embodiments, the acceleration measuring device has been described, but the present invention is not limited to this, and it is needless to say that the present invention may be applied to an angular velocity measuring device having a detecting portion for detecting an angular velocity.

That is, in the angular velocity measuring device, the Coriolis force F generated in the vibrator when the angular velocity Ω acts is
It is known that F = 2 mVΩ (where m is the mass of the oscillator, V is the vibration velocity of the oscillator, and Ω is the angular velocity). If this is not possible, the vibration speed (V) of the vibrator cannot be increased due to the damping effect of air, and the angular velocity detection sensitivity will decrease.

However, as in each of the above-described embodiments, the oxygen gas generated from the glass plate during the anodic bonding is sucked into the surroundings through the communication groove formed so as to surround the recessed portion, thereby measuring the angular velocity. The sealed space of the device can be brought to an ideal depressurized state, the vibration speed of the vibrator can be increased, and the angular velocity detection sensitivity can be increased.

[0076]

As described in detail above, according to the present invention of claim 1, at least one of the silicon plate and the glass plate is surrounded by the sealed space in a state of being separated from the sealed space. and since the formation of the communicating grooves which communicate to the outside,該連Tsumizo, when always communicates with the outside even when anodic bonding in a vacuum atmosphere Ru kept in a reduced pressure state co
In addition, the communication groove is tightly closed through the gap between the silicon plate and the glass plate.
Since communicates with the space in which the closed space is formed, gas generated during the bonding is discharged communicating groove located around the enclosed space through Ji <br/> Te outside, the enclosed space in a reduced pressure state can Ru.
Also, when the anodic bonding in the reduced pressure atmosphere is completed,
All the bonding surfaces of the silicon plate and glass plate are bonded and sealed
Since the space and the communication groove are shut off, it is possible to reduce the pressure
Keep the inside of the closed space in a decompressed state even when taken out.
It can be, by reducing the air resistance with respect to the detection unit it is possible to increase the detection sensitivity of the external force.

According to the second aspect of the present invention, the closed space is defined by joining the partition of the glass plate to the silicon plate, and the communicating groove is provided on the joining surface at the tip of the partition, whereby the communicating groove is anodically bonded. Even at any time, the gas generated at the time of joining is always kept in a depressurized state by communicating with the outside, so that the gas generated at the time of joining is discharged to the outside through the communicating groove to bring the hermetically sealed space into a depressurized state, and the detection sensitivity in the detection unit can be enhanced. .

According to the third aspect of the present invention, the closed space is defined by joining the partition wall of the glass plate to the silicon plate, the communication groove is located on the silicon plate, and the joint surface at the tip of the partition wall is joined. By providing the communication groove, even when performing anodic bonding, the communication groove communicates with the outside and is always kept in a depressurized state. The detection sensitivity of the detector can be increased.

In the manufacturing method according to the fourth aspect of the present invention, at least one of the silicon wafer and the glass plate is formed by the communicating groove forming step before the step of anodic bonding the silicon wafer and the glass plate in a reduced pressure atmosphere. Since the communication groove that surrounds the sealed space and communicates with the outside is formed on one of the joint surfaces, the communication groove communicates with the outside and is always kept in a reduced pressure state. Thus, gas generated during bonding through its communicating groove located around the enclosed space through the gap between the silicon plate and the glass plate is discharged to the outside, Ru can the enclosed space in a reduced pressure state. Also, in a reduced pressure atmosphere
When the anodic bonding is completed, the space between the closed space and the communication groove
Is shut off, so even if it is taken out from a decompressed atmosphere,
The closed space can be maintained in a reduced pressure state, the influence of air resistance on the detection unit can be reduced, and the detection sensitivity of external force can be increased.

According to the fifth aspect of the invention, after the joining step, a cutting step of cutting the silicon wafer and the glass plate in units of the closed space at the position of the partition wall is provided. A plurality can be manufactured.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an acceleration measuring device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a glass plate showing a state before a lid is formed.

FIG. 3 is a vertical cross-sectional view showing a state in which a recess is formed in a glass plate by a lid forming step.

FIG. 4 is a vertical cross-sectional view showing a state in which a communication groove is formed on a bonding surface of a glass plate by a communication groove forming step.

FIG. 5 is a plan view showing a state in which a communication groove is formed on a glass plate by a communication groove forming step.

FIG. 6 is a vertical cross-sectional view showing a state in which a silicon wafer and a glass plate are anodically bonded in a normal bonding process.

FIG. 7 is a vertical cross-sectional view showing a position to be cut by a cutting process by a chain double-dashed line.

FIG. 8 is a vertical cross-sectional view showing a state in which a silicon wafer and a glass plate are anodically bonded by a bonding process at the time of malfunction.

9 is an enlarged view of an essential part showing an enlarged part b in FIG.

FIG. 10 is a vertical sectional view showing an acceleration measuring device according to a second embodiment of the present invention.

FIG. 11 is a vertical cross-sectional view of a silicon wafer showing a state before forming a detection unit.

FIG. 12 is a view showing a detection part forming process and a communication groove forming process.
FIG. 3 is a vertical cross-sectional view showing a state in which a detection part is formed on a silicon wafer and a communication groove is formed in a frame part formed so as to surround the detection part.

FIG. 13 is a plan view showing a state in which a communication groove and a detection unit are formed on a silicon wafer.

FIG. 14 is a vertical cross-sectional view showing a state in which a silicon wafer and a glass plate are anodically bonded in a normal bonding process.

FIG. 15 is a vertical cross-sectional view showing a position to be cut by a cutting process by a chain double-dashed line.

FIG. 16 is a vertical cross-sectional view showing a state in which a silicon wafer and a glass plate are anodically bonded by a bonding process at the time of malfunction.

FIG. 17 is an enlarged view of an essential part showing an enlarged part c in FIG.

FIG. 18 is a plan view showing a partially brokenaway view of an acceleration measuring device according to a conventional technique.

19 is a vertical cross-sectional view as seen from the direction of arrows XIX-XIX in FIG.

FIG. 20 is a vertical cross-sectional view of a silicon wafer showing a state before forming a detection unit.

FIG. 21 is a vertical cross-sectional view showing a state in which a detector is formed on a silicon wafer by the detector forming step.

FIG. 22 is a plan view showing a state in which a detection portion is formed on a silicon wafer by the detection portion forming step.

FIG. 23 is a vertical cross-sectional view of a glass plate showing a state before forming a lid.

FIG. 24 is a vertical cross-sectional view showing a state in which a concave portion is formed in the glass plate by the lid forming step.

FIG. 25 is a plan view showing a state in which a concave portion is formed in the glass plate by the lid forming step.

FIG. 26 is a vertical cross-sectional view showing a state in which a silicon wafer and a glass plate are anodically bonded in a normal bonding process.

FIG. 27 is a vertical cross-sectional view showing a position to be cut by a cutting process by a chain double-dashed line.

FIG. 28 is a vertical cross-sectional view showing a state in which a silicon wafer and a glass plate are anodically bonded by a bonding process at the time of malfunction.

29 is an enlarged view of an essential part showing an enlarged part a in FIG. 28. FIG.

[Explanation of symbols]

2,52 Substrate (silicon plate) 3 detector 12,32 Lid (glass plate) 13,34 cutting partition 13A, 24A, 34A, 43A Bonding surface 21,61 Silicon wafer (silicon plate) 22,41 glass plate 23, 42 recess 24,43 partitions 31,51 Acceleration measuring device (external force measuring device) 33,53 closed space 35,55 Notch 44, 62 communication groove

Claims (5)

(57) [Claims] 1. A silicon plate, a glass plate provided by anodic bonding to the silicon plate in a reduced pressure atmosphere, and between the silicon plate and the glass plate when the silicon plate and the glass plate are bonded together. a picture made a sealed space, a detector for detecting a force applied from the outside provided in the sealed space located on the silicon plate, on one of the bonding surfaces at least one of said silicon plate or glass plate provided, wherein in a spaced apart condition an enclosed space surrounding the closed space, and an external force measuring apparatus der provided with a communicating groove which communicates to the outside
Thus, the communicating groove is formed when anodic bonding is performed in the reduced pressure atmosphere.
Is the gas generated from the space where the closed space is formed.
Discharge to the outside through the gap between the silicon plate and the glass plate,
When the anodic bonding in the reduced pressure atmosphere is completed,
An external force measuring device characterized in that it is cut off from the enclosed space . 2. The closed space is formed by closing a recess formed by surrounding a glass plate with a partition wall with the silicon plate, and the communication groove is provided on a joint surface at the tip of the partition wall. External force measuring device. 3. The closed space is formed by closing a concave portion formed by surrounding a glass plate with a partition wall with the silicon plate, and the communication groove is bonded on the silicon plate and at the bonding surface of the partition wall tip. The device is provided at a portion to be
External force measuring device described. 4. A silicon plate, a glass plate provided by anodic bonding to the silicon plate in a reduced pressure atmosphere, and between the silicon plate and the glass plate when the silicon plate and the glass plate are bonded together. A method for manufacturing an external force measuring device, comprising: a defined closed space; and a detection unit which is located on the silicon plate and is provided in the closed space to detect a force applied from the outside, wherein the silicon plate is a communication groove forming step of forming a communicating groove that communicates to at least one external on one of the bonding surfaces of the silicon wafer or glass plate to form a detecting portion forming step of forming a detecting portion on the silicon wafer, wherein the silicon plate and the said enclosed space clearance and the communication groove <br/> communication Ji with the glass plate in a state of communicated with the outside silicon wafer and a glass plate by anodic bonding in a vacuum atmosphere,
The gas generated in the space where the closed space is formed is connected to the continuous gas.
Discharge to the outside through the through groove, and perform anodic bonding in a reduced pressure atmosphere.
When is completed, the space between the closed space and the communication groove is
A method for manufacturing an external force measuring device, which comprises a joining step of shutting off . 5. The method of manufacturing an external force measuring apparatus according to claim 4, further comprising a cutting step of cutting the silicon wafer and the glass plate at the position of the partition wall in units of the closed space after the joining step.