JP2000261002A - Small-sized electronic component and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely connect a part between a function part and the outside, and seal a closed space. SOLUTION: An upper substrate 1 and a lower substrate 3 are face-bonded to the surface and the rear of a silicon substrate 2, respectively. An angular velocity detecting part 12 is accommodated in a closed space 4. An electrode 19 for detection, which faces the detecting part 12, is formed on the surface of the lower substrate 3. A lead part 19A of the electrode 19 is pinched by the lower substrate 3 and an electrode pinching part 18 of the silicon substrate 2. A ventilation line interconnected with the closed space 4 is formed in the vicinity of the side surface of the lead part 19A. The ventilation line is interconnected with an interconnection hole 22 which opens to the lower substrate 3. A gas in the closed space 4 is discharged through the ventilation line and the interconnection hole 22. A conducting film 23 is formed in the interconnection hole 22 and is electrically connected with the electrode 19 for detection, and the ventilation line can be sealed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small electronic component such as an angular velocity sensor, an acceleration sensor, and a mechanical filter, and more particularly, to a small electronic component for outputting an electric signal to the outside and a method of manufacturing the same.

[0002]

2. Description of the Related Art In general, angular velocity sensors, acceleration sensors, mechanical filters, and the like are widely known as small electronic components manufactured by silicon micromachining technology. In addition, such a small electronic component includes, for example, a silicon substrate as a semiconductor substrate,
And a glass substrate as an insulating substrate surface-bonded to the lower side. The silicon substrate is provided with, for example, a function unit for detecting an angular velocity, and the function unit is housed in a closed space sealed by two glass substrates.

Further, as such a small electronic component according to the prior art, there is known a small electronic component in which an electrode film is provided on the surface of a glass substrate and a signal from a functional unit is extracted by the electrode film (for example, Japanese Patent Application Laid-Open No. Hei 6-1994). No. 160420).
In this case, the glass substrate is provided with a through hole that opens toward the bonding surface with the silicon substrate, and the silicon substrate is formed with a groove-shaped step at the position where the through hole opens. The electrode film extends from the vicinity of the functional portion toward the step portion, and is electrically connected to a metallic coating provided in the through hole via a connection line provided in the step portion. Thereby, when the silicon substrate and the glass substrate are surface-bonded to each other, the small-sized electronic component according to the prior art forms the connecting wire provided on the step portion and the metallic coating provided on the through hole over the entire circumference of the through hole. Connection and wiring processing of the electrode film and the like are performed, and the through holes are sealed.

[0004]

However, in the above-mentioned prior art, however, the thickness of the electrode film formed on the glass substrate, the depth of the step formed in the groove, and the connection formed in the step. The thickness of the wire, the thickness of the metallic coating provided in the through hole, and the like may vary. For this reason, the electrode film does not come into contact with the connection lines, and electrical connection between them may not be possible. Further, the connection line in the step and the metallic coating in the through hole may not be able to be connected due to the variation. For this reason, there is a problem that the through hole cannot be sealed by the connecting wire and the metal coating, and the inside of the sealed space cannot be maintained in a reduced pressure state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention has a small size that can securely connect a functional unit to the outside and can seal a closed space. It is an object of the present invention to provide an electronic component and a method for manufacturing the same.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a semiconductor substrate having a functional part, and an insulating material which is surface-bonded to the semiconductor substrate and defines a sealed space for accommodating the functional part. It is applied to a small electronic component having a substrate.

The first aspect of the present invention is characterized in that a lead portion provided on the surface of the insulating substrate and sandwiched between the semiconductor substrate and an electrode portion extending from the lead portion into the closed space. An electrode film having: a communication hole penetrating the insulating substrate and penetrating at least a part of a lead portion of the electrode film; and a communication hole provided on an inner wall of the communication hole and electrically connected to the lead portion of the electrode film. And a connected conductive film.

With this configuration, the lead portion of the electrode film can be electrically connected to the conductive film, and the conductive film can reliably connect the electrode film to the outside.

According to a second aspect of the present invention, a ventilation line is provided between the semiconductor substrate and the insulating substrate, which is located near the side surface of the lead portion and extends from the sealed space to the communication hole, and the ventilation line is provided with the conductive line. That is, it is sealed by a film.

Thus, the gas and the like in the sealed space can be exhausted through the ventilation line, and the ventilation line can be sealed by the conductive film, and the sealed space can be sealed under reduced pressure.

A third aspect of the present invention resides in that the electrode portion of the electrode film is provided to face the functional portion of the semiconductor substrate. Thereby, since the electrode film can be used as a detection electrode for detecting the position of the functional unit that is displaced by external force or the like,
An external force acting on the small electronic component can be detected by a signal from the electrode film.

According to a fourth aspect of the present invention, since the communication hole is formed in a tapered shape that gradually decreases in diameter from the opening side of the insulating substrate to the semiconductor substrate, the inner wall of the communication hole covers substantially the entire surface when viewed from the opening side of the insulating substrate. The conductive film can be easily formed on the inner wall of the communication hole by using a means such as sputtering.

According to a fifth aspect of the present invention, since the function section is configured as an external force detecting section for detecting an external force including an angular velocity and an acceleration, for example, the small electronic component is configured as an angular velocity sensor and an acceleration sensor for detecting an angular velocity and an acceleration. be able to.

According to a sixth aspect of the present invention, since another insulating substrate is surface-bonded to the semiconductor substrate on the surface opposite to the surface to which the insulating substrate is bonded, two substrates are provided on the front surface and the back surface of the semiconductor substrate. And the functional part formed on the semiconductor substrate can be sealed.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a small electronic component, the method comprising: a first bonding step of bonding a semiconductor substrate to a first insulating substrate having a recess formed therein; Part processing step of processing a function part at a position to be processed, and an electrode film having, on a surface of a first insulating substrate, an electrode part located at a part facing the function part of the semiconductor substrate and a lead part extending from the electrode part An electrode film processing step of processing the second insulating substrate, and bonding the second insulating substrate to the semiconductor substrate in a state where the lead portion of the electrode film is sandwiched between the semiconductor substrate and the second insulating substrate; A second bonding step of forming a ventilation line along the line, a communication hole processing step of forming a communication hole penetrating the insulating substrate and drilling at least a part of a lead portion of the electrode film, and a communication hole with the ventilation line. And via the said income A deaeration step of deaeration of the inside of the recess, and a conductive film processing of processing a conductive film on the inner wall of the communication hole, electrically connecting the conductive film to a lead portion of the electrode film, and sealing the ventilation line. And the process.

According to such a method of manufacturing a small electronic component, a functional portion is formed on a semiconductor substrate by a functional portion processing step in a state where the first insulating substrate and the semiconductor substrate are bonded by the first bonding step. On the other hand, an electrode film is formed on the surface of the second insulating substrate by the electrode film processing step, and the lead portion of the electrode film is sandwiched between the semiconductor substrate and the second insulating substrate by the second bonding step. A second insulating substrate is in surface contact with the semiconductor substrate. At this time, a ventilation line is formed between the semiconductor substrate and the second insulating substrate along the side surface of the lead portion. Next, a communication hole is formed in the lower substrate by a communication hole processing step, and the inside of the housing recess is deaerated through the ventilation line and the communication hole by a deaeration step. Lastly, in a state where the inside of the housing recess is evacuated, a conductive film is processed into the communication hole by a conductive film processing step, and the lead portion of the electrode film and the conductive film are electrically connected, and the inside of the housing recess is evacuated. Can be sealed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A small electronic component according to an embodiment of the present invention will be described in detail with reference to FIGS.

In FIG. 1, reference numeral 1 denotes an upper substrate as a first insulating substrate having a thickness of about 400 μm, for example, made of a glass material or the like. An accommodation recess 1A for accommodating the portion 12 is formed.

Reference numeral 2 denotes a silicon substrate as a semiconductor substrate formed of conductive low-resistance single-crystal silicon. The silicon substrate 2 is subjected to an etching process so that a frame portion 11 to be described later, A part 12 is formed.

Reference numeral 3 denotes a lower substrate as a second insulating substrate having a thickness of about 400 μm, for example, made of a glass material or the like. 3A, and the back surface of the lower substrate 3 opposite to the bonding surface 3A is a non-bonding surface 3B. Further, a detection electrode 19 to be described later is formed at the center of the surface of the lower substrate 3. The lower substrate 3 is anodically bonded to the frame 11 of the silicon substrate 2 and the like, and defines a closed space 4 between the upper substrate 1 and the lower substrate 3.

Reference numeral 11 denotes a frame portion provided on the outer peripheral side of the silicon substrate 2, and an angular velocity detecting portion 12 as a functional portion (external force detecting portion) is provided in the frame portion 11. The angular velocity detection unit 12 detects the angular velocity Ω around the rotation axis XX when the angular velocity Ω acts around the rotation axis XX as shown in FIG. It is formed by performing an etching process. Then, the upper surface substrate 1 and the lower substrate 3 are surface-bonded to the front and back surfaces of the frame portion 11, so that the angular velocity detection unit 12 is housed in the closed space 4.

Here, the configuration of the angular velocity detector 12 will be described with reference to FIGS.

Are four support portions provided on the lower substrate 3, and 14 are recessed grooves 15 for the lower substrate 3.
Provided at a distance from the surface of the
The vibrating members supported by the supporting portions 13 are shown, respectively, and the vibrating member 14 can be displaced by these supporting beams 16 in the directions indicated by arrows A and B in FIG. . Further, the comb-shaped electrodes 1 are provided on both sides of the vibrating body 14.
4A and 14A are provided.

17, 17 are located on both sides of the vibrating body 14,
In the electrode support provided on the lower substrate 3, a comb-shaped electrode 17 </ b> A is provided on both sides of each electrode support 17, and each of the comb-shaped electrodes 17 </ b> A
Are engaged with each other.

Reference numeral 18 denotes an electrode holding portion provided between the two support portions 13, and the electrode holding portion 18 has a surface,
The back surface is surface-bonded to the upper substrate 1 and the lower substrate 3 by anodic bonding, and a lead 19A of a detection electrode 19 described later is sandwiched between the lower substrate 3 and the lower substrate 3.

Reference numeral 19 denotes a detection electrode as an electrode film provided at the center of the surface of the lower substrate 3 under the vibrating body 14. The detection electrode 19 is formed by sputtering as shown in FIG. , For example, a thickness of 0.3 μm by vacuum evaporation
It is formed in a thin film shape of about m. Further, the detection electrode 19 includes a lead portion 19A sandwiched between the lower substrate 3 and the electrode holding portion 18, and a lead member 19A extending from the lead portion 19A toward the center of the lower substrate 3, And an electrode portion 19B provided at a portion opposed to the above.

When the vibrating body 14 is displaced in the direction of arrow B by Coriolis force, the capacitance between the electrode portion 19B of the detection electrode 19 and the vibrating body 14 changes. For this reason, the detection electrode 19 detects the amount of displacement of the vibrating body 14 in the direction of arrow B by outputting a voltage signal or the like according to the change in the capacitance.

Reference numeral 20 denotes a thin tubular ventilation line which is provided between the lower substrate 3 and the electrode holding portion 18 and is provided on the peripheral side of the detection electrode 19.
When the lower substrate 3 and the electrode sandwiching portion 18 are joined while sandwiching them, the vicinity of the side surface of the detection electrode 19 is formed by being separated by the thickness dimension. An opening is formed in a communication hole 22 to be described later at an intermediate position of the ventilation line 20. As shown in FIGS. 3 and 4, the ventilation line 20 has a proximal end communicating with the closed space 4 and a distal end sealed with a conductive film 23 described later.

Reference numeral 21 denotes a via hole formed from the lower substrate 3 to the electrode holding portion 18 and the detection electrode 19, and the via hole 20 is connected to a tapered communication hole 22 provided through the lower substrate 3. , And a conductive film 23 provided on the inner wall of the communication hole 22.

Reference numeral 22 denotes communication holes opened on the non-joining surface 3B of the lower substrate 3, and each of the communication holes 22 is a tapered through hole provided through the lower substrate 3 as shown in FIG. Part 22A
A substantially semicircular notch 22B communicating with the through hole 22A and partially drilling the outer edge of the lead 19A; a through hole 22A in the electrode holding portion 18 of the silicon substrate 2; 22B, and a concave bottom portion 22C that is bored in communication with 22B.

Each communication hole 22 has, for example, a diameter of about 300 μm on the non-joining surface 3B side, which is an opening, and a diameter of about 100 μm on the joining surface 3A side. Therefore, each of the communication holes 22 is formed in a tapered shape whose diameter gradually decreases from the non-bonding surface 3B side of the lower substrate 3 toward the silicon substrate 2 side.

Reference numeral 23 denotes a conductive film provided on the inner wall of each communication hole 22. The conductive film 23 extends from the electrode holding portion 18 of the silicon substrate 2 to the non-bonding surface 3B (back surface) of the lower substrate 3. I have. The conductive film 23 is formed of a conductive metal material such as aluminum, and is formed to have a thickness of, for example, about 1 μm by using a method such as sputtering or vacuum deposition. As a result, the conductive film 23 is electrically connected to the lead 19A of the detection electrode 19 by being formed in the notch 22B of the communication hole 22. The conductive film 23 is formed over the entire inner wall of the communication hole 22 and seals the front end side of the ventilation line 20.

Reference numerals 24, 24,... Denote a plurality of via holes (only one is shown) formed from the lower substrate 3 to the support portion 13 of the angular velocity detector 12 and the electrode support portion 17, and each of the via holes 24 is The tapered communication hole 25 formed substantially in the same manner as the via hole 21 on the electrode holding portion 18 side and penetrating the lower substrate 3, and the conductive film 26 provided on the inner wall of the communication hole 25. It is configured. The via hole 24 electrically connects the support 13 and the electrode support 17 of the angular velocity detector 11 to the outside.

Are solder bumps formed at portions of the conductive films 23 and 26 of the via holes 21 and 24 which are located on the non-bonding surface 3B side of the lower substrate 3, and each of the solder bumps 27 is When the angular velocity sensor is mounted on a circuit board (not shown), the electrode pads provided on the circuit board and the conductive films 23 and 26 are electrically connected. As a result, the angular velocity detector 12 outputs an electric signal corresponding to the angular velocity Ω to an oscillation circuit, a detection circuit, and the like (both not shown) provided on the circuit board using the respective solder bumps 27.

In the angular velocity sensor configured as described above,
A drive signal is applied between the comb-shaped electrode 14A of the vibrating body 14 and the comb-shaped electrode 17A of the electrode supporting portion 17 through a solder bump 27, a conductive film 26, or the like from an external oscillating circuit. Vibrates in the A direction. In this state, when the angular velocity Ω around the rotation axis XX acts on the angular velocity sensor,
Coriolis force acts on the vibrating body 14, and the vibrating body 14 is displaced in the direction of arrow B according to the magnitude of the Coriolis force, and the separation distance between the vibrating body 14 and the detection electrode 19 changes.

At this time, the capacitance between the vibrating body 14 and the detecting electrode 19 changes according to the distance between the vibrating body 14 and the detecting electrode 19. A voltage signal or the like corresponding to the capacitance is applied to the conductive film 23 and the solder bump 2.
7 to the detection circuit. And the detection circuit,
The angular velocity Ω is calculated from the voltage signal from the detection electrode 19 and the like, and the angular velocity Ω applied around the rotation axis XX can be measured.

Next, a method of manufacturing the angular velocity sensor according to the present embodiment will be described with reference to FIGS.

First, FIG. 5 shows the silicon substrate 2 before processing such as etching processing. The silicon substrate 2 is processed with a frame portion 11 and an angular velocity detecting portion 12 by a later-described functional portion processing step.

In the thin portion processing step shown in FIG. 6, a mask (not shown) is formed on the back surface of the silicon substrate 2 and then a concave portion 15 is formed by etching, and the concave portion of the silicon substrate 2 is formed. The position corresponding to the groove 15 is the thin portion 2
A.

Next, in a first bonding step shown in FIG. 7, the upper substrate 1 having the accommodation recess 1A formed on the back surface is placed on the front surface of the silicon substrate 2 having the thin portion 2A. At this time, the thin portion 2A of the silicon substrate 2 is formed by the accommodation recess 1A.
The silicon substrate 2 and the upper substrate 1 are substantially aligned so as to cover. Then, while heating the silicon substrate 2 and the upper substrate 1 to a bonding temperature of, for example, about 400 ° C., a voltage of, for example, about 1000 V is applied to the silicon substrate 2 and the upper substrate 1, and the silicon substrate 2 and the upper substrate 1 Surface bonding is performed by bonding.

Next, in a functional part processing step shown in FIG. 8, a mask (not shown) in which the frame part 11 and the angular velocity detecting part 12 are modeled.
Is formed, and an etching process is performed through a mask from the back side of the silicon substrate 2 to form an angular velocity detector 12 in a thin portion 2A of the silicon substrate 2 corresponding to the accommodation recess 1A of the upper substrate 1, The frame 11 is machined on the outside.

Next, in the electrode film processing step shown in FIG. 9, a conductive metal material such as aluminum is applied to a substantially central portion of the lower substrate 3 by means such as sputtering over a thickness of about 0.3 μm. To form a film. As a result, a portion corresponding to the angular velocity detector 12 is provided at the center of the lower substrate 3 in the electrode portion 19.
B, and the portion corresponding to the electrode holding portion 18 is the lead portion 1
The detection electrode 19 which is 9A is formed.

Next, in the second bonding step shown in FIGS. 10 to 12, the silicon substrate 2 is placed on the surface of the lower While heating to the bonding temperature of about ℃, the lower substrate 3,
A voltage of, for example, about 1000 V is applied to the silicon substrate 2, and the silicon substrate 2 and the lower substrate 3 are surface-bonded by anodic bonding.

Since the detection electrode 19 is formed between the lower substrate 3 and the silicon substrate 2, the lower substrate 3 and the silicon substrate 2 are separated from each other by the thickness of the detection electrode 19. I do. However, since a voltage of about 1000 V is applied between the lower substrate 3 and the silicon substrate 2, the lower substrate 3 and the silicon substrate 2 come into contact with each other by being attracted by electrostatic attraction. As a result, a current flows at a portion where they are in contact, and the lower substrate 3 and the silicon substrate 2 are joined.

At this time, the lead 19 of the detection electrode 19
A is sandwiched between the lower substrate 3 and the silicon substrate 2, and the electrode 19 </ b> B is connected to the vibrator 14 of the angular velocity detector 12.
Face to face.

The lower substrate 3 and the silicon substrate 2 sandwiching the lead 19A are not anodically bonded because the lower substrate 3 and the silicon substrate 2 do not come into contact with each other. Also, the lower substrate 3 and the silicon substrate 2 are separated from each other by the thickness of the detection electrode 19 in the vicinity of the outer edge of the lead portion 19A, and are not anodic-bonded. Therefore, as shown in FIG. A substantially U-shaped ventilation line 20 is formed along the side surface of.

Since the upper substrate 1 and the lower substrate 3 are anodically bonded to the front and back surfaces of the silicon substrate 2, the upper substrate 1
A closed space 4 is defined between the lower substrate 3 and the lower substrate 3. The closed space 4 communicates with the ventilation line 20, and the ventilation line 20 opens to the outside through a communication hole 22 described later.

In the communication hole processing step shown in FIG. 13, a mask (not shown) in which circular communication holes 22 and 25 are formed is formed on the non-bonding surface 3B side of the lower substrate 3 and then sandblasted. The tapered communication holes 22 and 25 are formed in the lower substrate 3 by processing means such as processing and laser processing.

At this time, the communication hole 22 is formed by a through-hole portion 22 A penetrating through the lower substrate 3 and a through-hole portion 2.
A substantially semicircular cutout portion 22B that is formed in the outer edge side of the lead portion 19A so as to communicate with 2A and a concave bottom portion 22C formed in the electrode holding portion 18 is formed. Accordingly, the diameter of the communication hole 22 on the non-joining surface 3B side is about 300 mm.
μm, the diameter of the joining surface 3A side is about 100 μm, and the diameter is gradually reduced from the non-joining surface 3B to the joining surface 3A, and the communication hole 22 has a depth dimension of about 450 μm. The concave bottom portion 22 </ b> C is formed on the surface of the electrode holding portion 18.

Since the communication hole 22 is formed by partially piercing the outer edge of the lead portion 19A,
It is connected to an intermediate position of a ventilation line 20 formed near the outer edge of 9A.

Next, in the deaeration step shown in FIGS. 14 and 15, the lower substrate 3, the silicon substrate 2, the upper substrate 1, etc., in which the communication holes have been formed by the communication hole processing step, are placed in a reduced-pressure atmosphere. At this time, the closed space 4 communicates with the communication hole 22 through the ventilation line 20. For this reason, oxygen gas and the like flowing into the closed space 4 due to the anodic bonding are discharged to the outside through the ventilation line 20 and the communication hole 22. Thereby, the closed space 4 is evacuated, and the closed space 4 is substantially in a vacuum state. In this deaeration step, a metal mask (not shown) is arranged in advance on the non-bonding surface 3B side of the lower substrate 3 in accordance with the position of the communication hole 22 in preparation for a conductive film processing step described later. deep.

Finally, in the conductive film processing step shown in FIGS. 16 to 18, the metal mask (not shown) provided on the non-bonding surface 3B side of the lower substrate 3 is used as a mask and means such as sputtering is used. A thin film of metal such as aluminum is formed on the inner wall of the communication hole 22 of the lower substrate 3 to provide a conductive film 23. At this time, the lower substrate 3, the silicon substrate 2, the upper substrate 1, and the like are kept in a reduced pressure atmosphere. As a result, the lead 19A of the detection electrode 19 and the conductive film 23
It is joined in a semicircular arc shape at the position 2B.

The conductive film 23 is formed on the inner wall of the communication hole 22 where the ventilation line 20 is opened. Therefore, a portion of the conductive film 23 formed on the opening side of the ventilation line 20 serves as a sealing portion 23A as shown in FIG. As a result, the conductive film 23 seals the ventilation line 20 in a state where the closed space 4 is almost in a vacuum,
The closed space 4 can be kept under reduced pressure.

Further, simultaneously with the formation of the conductive film 23 in the communication hole 22, a conductive film 26 is formed in the communication hole 25.
A base metal for bumps such as nickel or platinum is provided on portions of the conductive films 23 and 26 located on the non-bonding surface 3B of the lower substrate 3, and solder (an alloy of lead and tin or the like) is further provided thereon. Is used to form a solder bump 27 (see FIG. 2).

However, according to the present embodiment, the sealed space 4 is defined between the lower substrate 3 and the upper substrate 1 by the second bonding step, and the lower substrate 3 and the silicon substrate 2 are connected to each other. A ventilation line 20 communicating with the closed space 4 is formed therebetween. Then, the ventilation line 20 is formed by the communication hole processing step.
The communication hole 22 is provided at an intermediate position of the communication line, so that the communication hole 22 can be connected to the ventilation line 20. Then, since the lower substrate 3 and the like are placed in the reduced pressure atmosphere by the degassing process, oxygen gas and the like in the closed space 4 can be discharged to the outside through the ventilation line 20 and the communication hole 22. Further, the conductive film 23 can be formed in the communication hole 22 by the conductive film processing step.

As a result, since the communication hole 22 is formed by drilling the lead 19A of the detection electrode 19, the detection electrode 1
A cutout portion 22 </ b> B constituting the communication hole 22 can be formed in the communication hole 9, and the cutout portion 22 </ b> B can be exposed inside the communication hole 22. As a result, the conductive film 23 is formed in the communication hole 22 and the detection electrode 19 and the conductive film 23 can be electrically reliably connected to each other. No disconnection occurs between the electrode 19 and the conductive film 23.

Further, the ventilation line 20 can be sealed while the closed space 4 is kept in a reduced pressure state by the sealing portion 23A of the conductive film 23. For this reason, since the air resistance applied to the vibrating body 14 of the angular velocity detecting unit 12 can be reduced, the vibrating body 14 can be vibrated at a high speed and with a large amplitude, and the detection sensitivity of the angular velocity can be improved. .

Then, a wiring process for making the detection electrode 19 and the conductive film 23 electrically connectable to the outside,
Since the sealing process for sealing the sealed space 4 in a vacuum state can be performed at the same time, the productivity can be improved as compared with the case where these processes are separately performed.

On the other hand, after the lower substrate 3 and the silicon substrate 2 are firmly joined in the lower substrate joining step, the communication holes 2
2, when the communication holes 22 are formed in the lower substrate 3 by using sandblasting or the like, no chips or the like are generated on the bonding surface 3A side of the lower substrate 3, and the lower substrate 3 A continuous communication hole 22 can be provided between the silicon substrate 2.

As a result, when the conductive film 23 of the via hole 21 is provided on the inner wall of the communication hole 22, disconnection of the conductive film 23 due to the chip is eliminated, and the conductive film 23 allows the angular velocity detector 12 to communicate with an external detection circuit or the like. The electrical connection can be reliably established between them.

The communication hole 22 of the via hole 21 is formed in a tapered shape in which the diameter gradually decreases from the non-bonding surface 3B of the lower substrate 3 toward the bonding surface 3A. When viewed from the 3B side, the inner wall of the communication hole 22 can be exposed over substantially the entire surface, and the conductive film 32 can be easily formed on the inner wall of the communication hole 22 by means of sputtering or the like in a state where the adhesion is enhanced. Can be processed.

In the above embodiment, the communication holes 22
Has a configuration in which the concave bottom portion 22C is recessed in the electrode holding portion 18. However, the present invention is not limited to this, and the concave bottom portion 22C 'is formed as in a communication hole 22' shown by a two-dot chain line in FIG. It may be formed on the lower substrate 3 and penetrate the electrode holding portion 18. In addition, the communication hole is formed on the lower substrate 3, the detection electrode 1, and the like.
9, the silicon substrate 2 and the upper substrate 1 may be formed so as to penetrate from the bottom to the top.

In the above embodiment, the communication holes 22 are formed in the through holes 22 A formed in the lower substrate 3, the notches 22 B provided in the detection electrodes 19, and the electrode holding portions 18. 19A and 20B, a through hole 31A formed in the lower substrate 3 and a notch provided in the detection electrode 19, as in the modification shown in FIGS. Section 31B and a substantially planar bottom section 31C which is formed of a back surface of the electrode holding section 18 and covers the through-hole section 31A and the like.
The communication hole 31 may be configured by the following.

In this case, before the silicon substrate 2 and the lower substrate 3 are surface-bonded, the lower substrate 3 is subjected to sandblasting or the like in advance to form a through-hole 31A, and the through-hole 31A is formed. The detection electrodes 19 are formed on the lower substrate 3 provided. At this time, a notch 31B is formed in the lead 19A of the detection electrode 19. Thereafter, the silicon substrate 2 and the lower substrate 3 are surface-bonded with the detection electrode 19 interposed between the silicon substrate 2 and the lower substrate 3. This allows
A ventilation line 20 is formed near the side surface of the lead 19A of the detection electrode 19. Finally, in the reduced pressure atmosphere,
1, a conductive film 32 is formed, and the detection electrode 19 and the conductive film 32 are formed.
Is connected, and the ventilation line 20 is sealed by the sealing portion 32A of the conductive film 32.

Further, in the above embodiment, the upper substrate 1 and the lower substrate 3 are surface-bonded to the front and back surfaces of the silicon substrate 2 as a semiconductor substrate. For example, the semiconductor substrate is made of SOI (Silicon On Insulator).
In the case of using a substrate, the lower substrate as an insulating substrate is surface-bonded to the back side of the SOI substrate without surface-bonding the upper substrate to the surface of the SOI substrate. A sensor can be formed.

In the above embodiment, the angular velocity sensor is described as an example of a small electronic component. However, the present invention is not limited to this, and may be applied to an acceleration sensor, a mechanical filter, and the like.

[0067]

As described above in detail, according to the first aspect of the present invention, the lead portion provided on the surface of the insulating substrate and sandwiched between the semiconductor substrate and the electrode extending from the lead portion into the closed space. A communication hole provided through the insulating substrate and penetrating at least a part of a lead portion of the electrode film; and a lead portion of the electrode film provided on an inner wall of the communication hole. Since the conductive film is provided with the electrically conductive film, the electrode film can be electrically and reliably connected to the outside by the conductive film.

According to the second aspect of the present invention, a ventilation line is provided between the semiconductor substrate and the insulating substrate and located near the side surface of the lead portion and extends from the sealed space to the communication hole. Since sealing is performed by the conductive film, gas and the like in the sealed space can be exhausted through the ventilation line, and the ventilation line can be sealed by the conductive film, and the sealed space can be sealed under reduced pressure. Therefore, by forming a conductive film in the communication hole, the wiring process for electrically connecting to the outside through the electrode film and the conductive film and the sealing process for sealing the sealed space in a vacuum state are performed simultaneously. Since these processes can be performed, productivity can be improved as compared with a case where these processes are separately performed.

According to the third aspect of the present invention, since the electrode portion of the electrode film is provided so as to face the functional portion of the semiconductor substrate, the electrode film is used as a detection electrode for detecting the position of the functional portion which is displaced by an external force or the like. The external force acting on the small electronic component can be detected by a signal from the electrode film.

According to the fourth aspect of the present invention, since the communication hole is formed in a tapered shape that gradually decreases in diameter from the opening side of the insulating substrate to the semiconductor substrate, the inner wall of the communication hole substantially covers the entire surface when viewed from the opening side of the insulating substrate. And a conductive film can be easily formed on the inner wall of the communication hole by using means such as sputtering.

According to the fifth aspect of the present invention, since the function section is configured as an external force detecting section for detecting an external force including an angular velocity and an acceleration, for example, a small electronic component can be used as an angular velocity sensor and an acceleration sensor for detecting an angular velocity, an acceleration and the like. Can be configured.

According to the invention of claim 6, the semiconductor substrate has:
Since another insulating substrate was surface-bonded to the surface opposite to the surface to which the insulating substrate was bonded, the function formed on the semiconductor substrate was performed by bonding the front side and the back side of the semiconductor substrate with two insulating substrates. The part can be sealed.

According to the method of manufacturing a small electronic component according to the present invention, the first bonding step, the functional part processing step, the electrode film processing step, the second bonding step, the communicating hole processing step, the deaeration step, Since the semiconductor substrate is formed by the conductive film processing step, the first insulating substrate and the semiconductor substrate are surface-bonded by the first bonding step, and a functional part is formed on the semiconductor substrate by the functional part processing step. On the other hand, an electrode film is formed on the surface of the insulating substrate by an electrode film processing step. Then, the semiconductor substrate and the insulating substrate are surface-bonded with the lead portion of the electrode film interposed therebetween in the second bonding step, and a ventilation line is formed between the semiconductor substrate and the insulating substrate along the side surface of the lead portion. I do. next,
A communication hole is formed in the lower substrate by the communication hole processing step, and the communication hole is communicated with the ventilation line. In the deaeration step, the inside of the accommodation recess is deaerated through the ventilation line and the communication hole, and in this state, a conductive film is formed in the communication hole by the conductive film processing step. Thus, the electrode film and the conductive film can be reliably electrically connected, and the ventilation line can be sealed by the conductive film, so that the inside of the accommodation recess can be maintained in a reduced pressure state.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an angular velocity sensor according to an embodiment.

FIG. 2 is a cross-sectional view showing the angular velocity sensor as viewed from the direction of arrows II-II in FIG.

FIG. 3 shows a lead portion of a detection electrode, a ventilation line, a communication hole,
FIG. 3 is a cross-sectional view showing a conductive film and the like, as viewed from a direction indicated by arrows III-III in FIG. 2.

FIG. 4 is a cross-sectional view showing a ventilation line and the like as viewed from a direction indicated by arrows IV-IV in FIG.

FIG. 5 is a longitudinal sectional view of the silicon substrate showing a state before an angular velocity detecting unit and a frame are formed.

FIG. 6 is a longitudinal sectional view showing a state where a thin portion is formed on a silicon substrate by a thin portion processing step.

FIG. 7 is a longitudinal sectional view showing a state in which a silicon substrate and a lower substrate are anodically bonded in a first bonding step.

FIG. 8 is a longitudinal sectional view showing a state in which an angular velocity detecting section is formed on a silicon substrate by a functional section processing step.

FIG. 9 is a longitudinal sectional view showing a state where detection electrodes are formed on a lower substrate by an electrode film processing step.

FIG. 10 is a longitudinal sectional view showing a state before the silicon substrate and the lower substrate are anodically bonded in a second bonding step.

FIG. 11 is a longitudinal sectional view showing a state in which a silicon substrate and a lower substrate are anodically bonded.

FIG. 12 is a cross-sectional view showing a lead portion of a detection electrode, a ventilation line, and the like, as viewed from a direction indicated by arrows XII-XII in FIG.

FIG. 13 is a longitudinal sectional view showing a state in which a communication hole is formed in a lower substrate, a detection electrode, and an angular velocity detection unit by a communication hole processing step.

FIG. 14 is an enlarged cross-sectional view showing a communication hole and the like in a state where gas in a closed space is exhausted by a deaeration step.

15 shows arrows in FIG. 14 showing ventilation lines, communication holes, and the like.
It is sectional drawing seen from the XV-XV direction.

FIG. 16 is a longitudinal sectional view showing a state in which a conductive film is formed on the inner wall of the communication hole by a conductive film processing step.

FIG. 17 is an enlarged sectional view showing a communication hole and the like in FIG. 16 in an enlarged manner.

18 is an enlarged cross-sectional view showing the ventilation line, the communication hole, and the conductive film in an enlarged manner as viewed from the direction of arrows XVIII-XVIII in FIG. 17;

FIG. 19 is an enlarged sectional view showing a communication hole and the like according to a modification of the present invention in an enlarged manner.

20 is an enlarged cross-sectional view showing the ventilation line, the communication hole, and the conductive film in an enlarged manner as viewed from the direction indicated by arrows XX-XX in FIG. 19;

[Explanation of symbols]

 Reference Signs List 1 upper substrate (first insulating substrate) 1A accommodation recess 2 silicon substrate (semiconductor substrate) 3 lower substrate (second insulating substrate) 4 sealed space 12 angular velocity detecting unit (functional unit) 18 electrode holding unit 19 detecting electrode (Electrode film) 19A Lead part 19B Electrode part 20 Ventilation line 22, 31 Communication hole 23, 32 Conductive film

Claims (7)

[Claims] 1. A small electronic component comprising: a semiconductor substrate having a functional part; and an insulating substrate which is surface-bonded to the semiconductor substrate and defines a sealed space for accommodating the functional part, provided on a surface of the insulating substrate. And an electrode film having a lead portion sandwiched between the semiconductor substrate and an electrode portion extending from the lead portion into the sealed space, and piercing at least a part of the lead portion of the electrode film through the insulating substrate. A small electronic component comprising: a communication hole provided; and a conductive film provided on an inner wall of the communication hole and electrically connected to a lead portion of the electrode film. 2. The semiconductor device according to claim 1, wherein:
The small electronic component according to claim 1, wherein a ventilation line is provided near the side surface of the lead portion and extends from the closed space to the communication hole, and the ventilation line is sealed with the conductive film. 3. The small electronic component according to claim 1, wherein an electrode portion of the electrode film faces a functional portion of the semiconductor substrate. 4. The small-sized electronic component according to claim 1, wherein said communication hole is formed in a tapered shape such that a diameter of said communication hole is gradually reduced from an opening side of said insulating substrate to said semiconductor substrate. 5. The apparatus according to claim 1, wherein the function unit is configured as an external force detecting unit that detects an external force including an angular velocity and an acceleration.
The small electronic component according to 2, 3, or 4. 6. The small-sized semiconductor device according to claim 1, wherein another insulating substrate is surface-bonded to the semiconductor substrate on a surface opposite to a surface to which the insulating substrate is bonded. Electronic components. 7. A first joining step of joining a semiconductor substrate to a first insulating substrate having an accommodation recess formed therein, and a functional part processing step of machining a functional portion on the semiconductor substrate at a position corresponding to the accommodation recess. An electrode film processing step of processing an electrode film having an electrode portion located on a surface of a first insulating substrate facing a functional portion of the semiconductor substrate and a lead portion extending from the electrode portion; Bonding the second insulating substrate to the semiconductor substrate in a state where the lead portion is sandwiched between the semiconductor substrate and the second insulating substrate, and forming a ventilation line along a side surface of the lead portion. A communication hole processing step of forming a communication hole penetrating the insulating substrate and penetrating at least a part of a lead portion of the electrode film; and evacuating the inside of the accommodation recess through the ventilation line and the communication hole. A deaeration step, and Forming a conductive film on an inner wall, electrically connecting the conductive film to a lead portion of the electrode film, and sealing the ventilation line.