JP2000046863A - Mechanical quantity sensor - Google Patents

Abstract

(57) [Problem] To provide a mechanical quantity sensor that does not short-circuit between electrodes. SOLUTION: The diaphragm 1 has a thin portion 11 to which a mass portion 13 is fixed and deformed in accordance with displacement of the mass portion 13, and a frame 12 to which the thin portion 11 is fixed, and is formed while leaving a frame 22 on a peripheral edge. Pit with small depth 2
1, a pad forming surface 24 formed outside the frame 22,
Metal film electrode 25 formed in depression 21, pad formation surface 2
4, the pad 26, the metal film electrode 25 and the pad 26
In the mechanical quantity sensor having the stopper 2 composed of the wiring 27 connecting the diaphragm frame 12 and the stopper frame 22 and forming the groove 23 for passing the wiring 27 on the joint surface where the diaphragm frame 12 and the stopper frame 22 are joined, the groove 23 has the bent portion 231. A mechanical quantity sensor formed in a crank-shaped groove 230 and having a pocket 232 formed near a bent portion 231.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic quantity sensor, and more particularly, to a dynamic quantity sensor which does not cause malfunction due to conductive foreign matter.

[0002]

2. Description of the Related Art A conventional example will be described with reference to FIG. FIG.
FIG. 3A is a perspective view illustrating a diaphragm of a conventional example of a dynamic quantity sensor, and FIG. 3B is a perspective view illustrating a stopper. In FIG. 3A, reference numeral 1 denotes the entire diaphragm. The diaphragm 1 is formed using a silicon substrate which is a semiconductor in this conventional example as a raw material. The surface of the raw material silicon substrate is subjected to a well-known and commonly used anisotropic etching process, thereby forming a thin portion 11 by etching. As a result, a diaphragm frame 12 is integrally formed around the periphery and a mass portion is formed at the center. The diaphragm 1 is formed by integrally forming the remaining portions 13. In this manner, an integral diaphragm having the mass portion 13 supported on the peripheral diaphragm frame 12 via the thin portion 11 which is an elastic body is formed.

In FIG. 3B, reference numeral 2 denotes the entire stopper. The stopper 2 is made of a glass plate as a raw material in this conventional example. By subjecting the surface of the raw material glass plate to a well-known and commonly used chemical or mechanical etching process, a depression 21 having a very small depth is formed by etching, leaving a stopper frame 22 on the periphery. In this case, a pad forming surface 24 having a height lower than the upper surface of the stopper frame 22 is formed outside the stopper frame 22 and a part of the stopper frame 22 is formed with a groove 23 having a depth equal to the depth of the depression 21. Then, the dent 21 and the pad forming surface 24 communicate with each other. The depression 21 of the stopper 2 thus configured
A metal film is formed on the surface of the substrate by a metal sputtering technique, and this is used as a metal film electrode 25. When this metal film is formed, the pad 26 is simultaneously formed on the pad forming surface 24, and the wiring 27 connecting the metal film electrode 25 and the pad 26 is also formed simultaneously. Groove 23 and wiring 2
7, a wiring portion 28 is formed.

Here, the frame 12 of the diaphragm 1 in FIG. 3A and the frame 22 of the stopper 2 in FIG. 3B are integrated by, for example, an adhesive or anodic bonding, and the diaphragm 1 and the stopper 2 are integrated. Thus, a diaphragm structure of the acceleration sensor is formed. Referring to FIG. 4, this is a diagram of the wiring portion 28 of the diaphragm structure viewed from above. FIG. 4A shows that the depth formed in a part of the stopper frame 22 when the recess 21 is formed by etching is
A straight groove 23 equal to a depth of 1 is shown. In the linear groove 23, a wiring 27 connecting the metal film electrode 25 and the pad 26 is formed. Referring to FIG. 4B, this is also a view of the wiring portion 28 of the diaphragm structure viewed from above, and the groove 23 of the wiring portion 28 is formed in a crank shape.

[0005] In the conventional example of FIGS. 3 and 4 described above, the groove 23 of the wiring portion 28 is formed on the stopper side.
Reference numeral 3 denotes a diaphragm frame 12 on the diaphragm 1 side. In this case, since the groove 23 is not formed in the frame 22 of the stopper 2, the wiring 27 is formed from the depression 21 over the upper surface of the stopper frame 22 and reaches the pad 26. The wiring 27 formed over the upper surface of the stopper frame 22 passes through the groove 23 formed in the diaphragm frame 12, so that no gap is formed between the diaphragm frame 12 and the stopper frame 22 when they are joined. Can be joined.

[0006] Consider the use of a diaphragm structure as a physical quantity detector of an acceleration sensor. When an acceleration in the vertical direction on the paper of FIG. 3 is applied, an inertial force acts on the mass unit 13. Thereby, the capacitance between the mass portion 13 and the thin portion 11 and the metal film electrode 25 of the stopper 2 changes. The input acceleration can be detected by detecting the change in the capacitance. When the acceleration in the vertical direction on the paper in FIG. 3 is input to the diaphragm structure,
As a result of the inertial force acting on the mass portion 13, the capacitance between the thin portion 11 of the diaphragm 1 and the metal film electrode 25 of the stopper 2 changes. Therefore, the input acceleration is detected by detecting the change in the capacitance. can do.

[0007]

DISCLOSURE OF THE INVENTION The above diaphragm 1
In manufacturing either of the stopper 2 and the stopper 2, instead of manufacturing one by one, a large number of the same diaphragms 1 or stoppers 2 are simultaneously formed in a matrix on one large wafer. Then, these two wafers are joined by, for example, an adhesive or anodic bonding, and then subjected to dicing to produce individual cuts.

Here, when dicing the diaphragm 1 using a silicon semiconductor wafer as a raw material, cutting is performed while supplying a cooling liquid to a place where the silicon semiconductor wafer and the dicing blade are in contact with each other.
At this time, fine particles of silicon semiconductor, which are conductive foreign substances, are generated, and the silicon semiconductor fine particles may enter the groove 23 by being contained in the cooling liquid and stay there. This may cause a short circuit between the metal-coated electrode 25 side and the diaphragm 1 side of the diaphragm structure formed by joining the diaphragm 1 and the stopper 2, whereby a capacitance can be formed between the two. Disappears. The conductive foreign matter is generated not only from the workpiece, but also due to wear of the dicing blade during dicing. In the case where the stopper 2 is processed using glass as an insulating material as a raw material, a conductive foreign matter is similarly generated due to wear of the dicing blade, and when the groove 23 is formed in the stopper frame 22, there is a possibility that the foreign matter will stay there. is there. The stagnation of the conductive foreign matter occurs when the groove 23 is formed linearly or when the groove 23 is formed in a crank shape.

The present invention is to provide a dynamic quantity sensor having a diaphragm structure which solves the above-mentioned problem, in which conductive foreign matter is unlikely to stay in a region of the groove 23 where the wiring 27 is formed.

[0010]

Means for Solving the Problems Claim 1: Mass part 13,
The diaphragm 1 includes a thin portion 11 to which the mass portion 13 is fixed and deformed in accordance with the displacement of the mass portion 13, and a diaphragm frame 12 to which the thin portion 11 is fixed, and a stopper frame 22 is formed around the periphery. Recess 21 having a very small depth, a pad forming surface 24 formed outside the stopper frame 22, a metal film electrode 25 formed in the recess 21, a pad 26 formed in the pad forming surface 24, a metal film electrode A mechanical sensor having a diaphragm 2 having a stopper 2 consisting of a wiring 27 connecting the pad 25 and the pad 26 and having a groove 23 for passing the wiring 27 formed on a joint surface where the diaphragm frame 12 and the stopper frame 22 are joined. , The groove 23 is formed as a crank-shaped groove 230 having a bent portion 231, and a pocket 232 is formed near the bent portion 231. You configure the academic amount sensor.

Claim 2: In the dynamic quantity sensor according to claim 1, the crank-shaped groove 230 constitutes a dynamic quantity sensor formed on one of the diaphragm side and the stopper side. Claim 3: In the physical quantity sensor according to any one of claims 1 and 2, the pocket 232 constitutes a physical quantity sensor formed adjacent to the bent portion 231.

Further, claim 4: claim 1 and claim 2
In the physical quantity sensor described in any one of the above, the pocket 232 constitutes a physical quantity sensor formed slightly apart from the bent portion 231. Claim 5: In the physical quantity sensor according to any one of Claims 1 to 4, the pocket 232 is formed along the extending direction from the outside to the inside of the crank-shaped groove 230. Was configured.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram illustrating an embodiment of a diaphragm structure. FIG. 1A is a perspective view illustrating an embodiment of a diaphragm of a physical quantity sensor, and FIG. 1B is a perspective view illustrating a stopper. FIG.
2A and 2B are diagrams for explaining an embodiment of a wiring portion. 1 and 2, the same reference numerals as those of the conventional example in FIGS. 3 and 4 indicate the same members.

As will be described with reference to FIG. 1, this embodiment also has a mass portion 13 which is fixed and deforms in accordance with the displacement of the mass portion 13, similarly to the conventional example of the physical quantity sensor. A diaphragm 21 comprising a diaphragm frame 12 to which the thin portion 11 is fixed, and a very small recess 21 formed by leaving a stopper frame 22 on the periphery, formed outside the stopper frame 22 Pad forming surface 24, metal film electrode 2 formed in depression 21
5, a pad 26 formed on the pad forming surface 24, and a stopper 2 including a wiring 27 connecting the metal film electrode 25 and the pad 26. Then, the diaphragm frame 12 and the stopper frame 22 are joined, and a groove 23 for passing the wiring 27 is formed on the joining surface.

In the embodiment of the present invention, the groove 23 is formed as a crank-shaped groove 230 having a bent portion 231, and a pocket 232 is formed near the bent portion 231. Although the illustrated crank-shaped groove 230 is formed on the stopper 2 side, it is formed on either the diaphragm 1 side or the stopper 2 side. FIG. 2A shows that the wiring portion 28 is enlarged and a pocket 232 is formed adjacent to the bent portion 231. FIG. 2 (b) shows that the wiring portion 28 is enlarged and the pocket 232 is formed slightly apart from the bent portion 231.

The pocket 232 is formed in the crank-shaped groove 23.
0 is formed along the extending direction from the outside to the inside. By adopting the above configuration, conductive foreign substances that are contained in the cooling liquid and enter in the dicing process are captured in the pocket 232. That is, the coolant flows along the crank-shaped groove 230. However, when the coolant reaches the bent portion 231, conductive foreign substances contained therein are pushed to the outside of the flow of the coolant, and The pocket 232 that is formed will be captured. As a result, the conductive foreign matter entering the pocket 232 during the dicing process is trapped in the region of the groove 23 where the wiring 27 is formed. Short circuits are almost eliminated. In particular, by forming the pocket 232 along the direction in which the conductive foreign matter enters, the pocket 232 is more appropriately captured by the pocket 232.

[0017]

As described above, according to the present invention, the groove of the wiring portion is formed as a crank-shaped groove having a bent portion, and a pocket is provided near the bent portion, so that the conductive material that has entered the groove is formed. The conductive foreign matter can be excluded from the region where the wiring is formed, and the short circuit between the metal film electrode side and the diaphragm side hardly occurs.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment. FIG. 1A is a perspective view illustrating a diaphragm, and FIG. 1B is a perspective view illustrating a stopper.

FIG. 2 is a diagram illustrating an example of a wiring unit.

3A and 3B are diagrams illustrating a conventional example. FIG. 3A is a perspective view illustrating a diaphragm, and FIG. 3B is a perspective view illustrating a stopper.

FIG. 4 is a diagram illustrating a conventional example of a wiring unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diaphragm 11 Thin part 12 Diaphragm frame 13 Mass part 2 Stopper 21 Depression 22 Stopper frame 23 Groove 230 Crank-shaped groove 231 Bent part 232 Pocket 24 Pad formation surface 25 Metal film electrode 26 Pad 27 Wiring 28 Wiring part

Claims (5)

[Claims] 1. A diaphragm comprising a mass portion, a thin portion in which the mass portion is fixed and deformed in response to displacement of the mass portion, and a diaphragm frame in which the thin portion is fixed, and formed with a stopper frame on the periphery. A dent with an extremely small depth, a pad forming surface formed outside the stopper frame,
It has a metal film electrode formed in the depression, a pad formed on the pad formation surface, and a stopper composed of a wire connecting the metal film electrode and the pad, and allows the wiring to pass through a joint surface where the diaphragm frame and the stopper frame are joined. A dynamic quantity sensor comprising a diaphragm structure having a groove, wherein the groove is formed as a crank-shaped groove having a bent portion, and a pocket is formed near the bent portion. 2. The physical quantity sensor according to claim 1, wherein the crank-shaped groove is formed on one of the diaphragm side and the stopper side. 3. The physical quantity sensor according to claim 1, wherein the pocket is formed adjacent to the bent portion. 4. The physical quantity sensor according to claim 1, wherein the pocket is formed slightly apart from the bent portion. 5. The dynamic quantity sensor according to claim 1, wherein the pocket is formed along an extending direction from the outside to the inside of the crank-shaped groove. Quantity sensor.