JPH08304081A - Inertia sensor assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inertia sensor assembly which can be assembled easily and can sense the rotation about each axis and acceleration in a three- dimensional system comprising three orthogonal axes. SOLUTION: A chip 1' incorporates two tuning fork type sensors 2' and a pallet type one-dimensional acceleration sensor 9. A mortise 10 and a tongue 11 are formed closely to the fringe of the chip 1' such that each chip 1' is held while making an angle with respect to other chip by same technology or process as that for forming the tuning fork 2' and the pallet. Since three chips 1' are coupled through the mortise 10 and the tongue 11, quadruple rotation and double translation can be sensed in all three axes of X, Y and Z.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inertial sensor assembly including first and second planar members each having an inertial sensor.

[0002]

It is known to micromachine solid state inertial sensing devices from monolithic materials such as silicon. Such a sensing device is a "tuning fork" (in the form of a solid rate gyro) that produces a detectable resonance based on rotational acceleration, or a cantilevered mass that produces a detectable displacement based on translational acceleration. It is equipped with a form for vibrating "Hera" (form of solid accelerometer).

When the material for microfabrication of such a device is completed, such a material will be a solid inertial sensing device or 〃
It is known to integrate the analog and / or digital electrical drive, sensing, arithmetic and signal generator required to operate the chip.

[0004]

Since such a conventional device is originally microfabricated from a two-dimensional flat material, the tuning fork and spatula thus formed are arranged in the material plane. The tuning fork type rate gyro thus formed senses the rotation around the axis of symmetry, and the spatula type accelerometer formed in this way senses the acceleration in the direction orthogonal to the plane of symmetry. In general, an array of such devices cannot detect rotation about two or more axes and acceleration in one or more directions.

Two such planar array devices have been assembled in a three-dimensional configuration to sense rotation about three orthogonal axes. Three devices have been similarly assembled to sense acceleration in three orthogonal axes. In order to accurately measure the effects of inertia, the assembly must be aligned in exactly the orthogonal fashion. Since the planar array device is small, it is costly to arrange and maintain them so that they are exactly orthogonal to each other during assembly.

It is an object of the present invention to provide an improved inertial sensor assembly and manufacturing method.

[0007]

To this end, the present invention provides an inertial sensor assembly comprising first and second planar members, each having an inertial sensor, wherein said planar members are engaged with each other to form a planar shape. It is characterized in that surface features are formed so as to hold the members at an angle to each other.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION It is preferable that flat members are arranged and assembled so as to be orthogonal to each other. It is preferable that the surface-shaped portion is located around the edge of the planar member and is configured by protrusions and depressions that are alternately provided along the edge of the planar member.
The surface profile of the at least one planar member preferably comprises at least one opening in the planar member.

Further, it is preferable that the assembly has three planar members that are assembled orthogonally to each other by the engagement of the surface-shaped portions.

Furthermore, the sensor is a solid vibration inertial sensor, and it is preferable that each of the planar members has two inertial sensors arranged at right angles to each other. The sensor preferably comprises an acceleration sensor. Further, it is preferable that the sensor be finely processed from the material of the planar member.

In addition, the planar member is preferably supported by associated electronics for the sensor. The planar members are preferably electrically interconnected with each other at a position near the line of intersection of the planar members.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

First, referring to FIG. 1, a planar silicon chip 1 is constructed by incorporating a tuning fork type rotation sensor 2 integrally finely processed in the central portion thereof. The sensor 2 is sensitive to rotational acceleration about an axis X parallel to the arm of the tuning fork and is arranged in the plane of vibration. Also,
The sensor 2 includes an electric truck 5 and an integrated arithmetic unit 6
Under the influence of the excitation driver 3 and the resonance sensor 4 connected to, the arithmetic unit 6 is connected to the electric connector pad 7 on the edge of the chip. The edge of the tip is microfabricated by the same technique or process used to form the tuning fork 2, but at this time, the edge lap connection shape 8 is formed in the same working process. The joint shape 8 is a rectangular protrusion and a depression that are continuous along the edge of the chip 1.

Referring to FIG. 2, there is shown another configuration of a planar silicon chip 1'incorporating an array of inertial sensors, which array comprises two microfabricated tuning fork type rotation sensors 2'aligned at a right angle. The rotational accelerations about the axes X and Y are detected. Also, chip 1 '
Has a spatula-type one-dimensional acceleration sensor 9 which is micromachined integrally, and the acceleration sensor 9 is provided with an axis Z perpendicular to the sensor plane.
The translational acceleration in the direction (not shown) is detected. In the vicinity of the edge, the tip 1'is micromachined by the same process used to form the tuning fork 2'and spatula 9,
At this time, the tenon hole 10 is formed in the main body, and the tenon tongue piece 11 protruding so as to match the tenon hole is formed in the edge, and the electric connector pad 7 (FIG. 7) is provided on each.

FIG. 3 is an assembly of three of the planar silicon chip 1 shown in FIG. 1 in which each edge lap connection shape 8 is interconnected to form a circle about orthogonal axes X, Y and Z. Form a three-dimensional sensing device capable of sensing rotation.

In FIG. 4, another means of the present invention is shown in FIG.
It shows before assembling the three planar array silicon chips 1'of FIG. After assembly, the mortise 10 and the mortise tongue 11 are interconnected to form a three-dimensional sensing device, and the tuning fork sensors 2'having different alignments are used to double the rotational accelerations of the three axes X, Y and Z respectively. Sensing can be done. This assembly also includes a spatula sensor 9
The same translational acceleration of the three axes X, Y and Z can be sensed by each. Further, the sensors can be aligned with each other or oriented differently and integrally formed on each chip to increase the multiplicity and / or redundancy of the sensing capability of the assembly for each axis.

FIG. 5a shows a six-piece closed assembly 12 of the silicon chip 1'shown in FIG. 2, which assembly 12 has quadruple rotation sensing and double translational movement in all three axes. It can perform sensing and sensing. FIG. 5 b shows a pedestal carrier chip 13 suitable for mounting the assembly 12. It has a recess 14 which receives the tenon 11 of the assembly 12, as shown in Figure 5c. The carrier chip 13 electrically connects this integrated assembly to the connector pads 15 and tracks 16 and other electrical devices (not shown) that are aligned to receive the electrical connection with the assembly 12. The terminal pad 17 has a shape for

FIG. 6 is a partially enlarged view showing an electrical connector pad 7 in an edge-wrap coupling shape 8 of each chip 1 in which the two silicon chips 1 shown in FIG. 1 are aligned with each other. is there. The pads 7 on the two chips are the solder plug 18 shown in FIG. 7 and the pad 7 shown in FIG.
It can be electrically connected by wire bonding.

FIG. 9a shows a sensor chip 1'shown in FIG.
2 shows the surface structure of the matching tenon 10 and tenon tongue 11 in two of the above. The electrical connector pads 7, which are on the surface shaped for the mortise and tenon tongue to join, are arranged to connect to each other on the mating surfaces of the two chips. Since the tenon 10 and tenon tongue 11 are wedge-shaped, the residual stress pressure of the interference fit maintains the connection between the electrical connector pads 7 when assembled as shown in FIG. 9b.

FIG. 10a shows the edge-wrapped shape of the silicon chip 1 shown in FIG.
Are formed in a partially protruding state by the photo-edging material removing process used to form the edge-wrap bonded shape.

When the two chips 1 are assembled together,
The protrusion 7'on one chip has a pad 7 on the edge-wrapped feature of the other chip, as shown in Figure 10b.
Connected in a distorted state, electrically connecting the chip.

FIG. 11a shows the interconnection of the edge-wrapped shapes 8 of the silicon chip 1 shown in FIG. 1 aligned with each other, showing another configuration of the electrically conductive pads 7 and the tracks 5 arranged on the outside. The pads 7 are interconnected by other electrical assembly components 20, which electrically conductive projections 7 "interconnect each with a track 5".
A non-transmission carrier material having As shown in FIG. 11c, the projecting portion 7 ″ projects at a right angle and is in a position where it is connected to the pad 7 on the chip 1, so that the circuits on the two chips can be electrically connected.

The interconnections are possible in other forms. It is not important to assemble the planar chips in a right angle arrangement. When these are assembled together,
It does not necessarily have to be a right angle. The inertial sensor is preferably formed from the material of the planar member itself, but it is also possible to form the inertial sensor independently and then attach it to a mounting board formed with interengaging surface formations. .

The rigidity of the assembly and / or the integrity of the structure depends on the nature of the geometrical coupling geometry and the electrical connections. Conventional bonding or potting techniques can be utilized to improve the rigidity of the structure.

By varying the shape of the sensor in the planar device during or after formation and before assembly, vibration resonance and the effects of unwanted cross-coupling between other sensors are avoided. can do.

[Brief description of drawings]

FIG. 1 is a plan view of a sensor chip having an edge lap connection shape.

FIG. 2 is a plan view of a chip having a plurality of sensors and another shape in which a mortise and tenon pieces are combined.

3 is a perspective view of the three-sensor assembly shown in FIG. 1. FIG.

4 is an exploded view of the three-sensor assembly shown in FIG. 2. FIG.

5a is a perspective view of an assembly of six of the sensor chips shown in FIG. 2. FIG. 5b is a perspective view of a pedestal carrier chip to which the assembly shown in FIG. 5a can be attached. 5c is a perspective view of the assembly shown in FIG. 5a attached to the carrier chip shown in FIG. 5b.

FIG. 6 is a partial perspective view showing the coupling between the two sensor chips shown in FIG.

FIG. 7 is a cross-sectional view showing an electrical connection between two sensor chips.

FIG. 8 is another cross-sectional view showing an electrical connection between two sensor chips.

9a is a partial perspective view of the front assembly showing the combined shape of the two sensor chips shown in FIG. 2. FIG. 9b is a partial perspective view showing a coupled state between the two sensor chips shown in FIG. 9a. FIG.

10A is another partial perspective view of the coupling shape having the electrical connector of the sensor chip shown in FIG. 1 before assembly. FIG. FIG. 10b is a partial perspective view showing a coupled state between the two sensor chips shown in FIG. 10a.

11a is a partial perspective view showing an assembled sensor chip of the type shown in FIG. 1. FIG. FIG. 11b is a partial perspective view showing an electrical interconnection element suitable for coupling the assembled sensor chip shown in FIG. 11a. c is FIG.
The two interconnected sensor chips shown in FIG.
FIG. 6 is a partial perspective view showing a combined state in which the components are electrically connected by the interconnection element shown in FIG.

[Explanation of symbols]

 1 Planar Silicon Chip 2 Tuning Fork Type Rotation Rate Sensor 3 Excitation Driver 4 Resonance Sensor 6 Integrated Computing Unit 7 Electrical Connector Pad 8 Edge Wrap Joint Shape 9 Spatula Type One-Dimensional Accelerometer 10 Mortise Hole 11 Mortise 12 Assembly 13 Pedestal Shape Carrier chip 14 Recess 15 Connector pad 16 Track 17 Terminal pad 18 Solder plug 20 Electrical assembly components

Claims (12)

[Claims] 1. An inertial sensor assembly comprising first and second planar members each having an inertial sensor, wherein planar members (1, 1 ') are engaged with each other so that the planar members form an angle with each other. Inertial sensor assembly, characterized in that it has surface features (8, 10, 11) arranged to hold it in place. 2. The inertial sensor assembly according to claim 1, wherein the planar members (1, 1 ') are assembled so as to be orthogonal to each other. 3. The surface shape portion (8, 10, 11) is located near the edge of the planar member.
Or the inertial sensor assembly according to 2. 4. Inertial sensor assembly according to claim 3, characterized in that the surface profile is constituted by projections and depressions (8) arranged alternately along the edge of the planar member (1). 5. The surface profile of at least one planar member (1 ′) comprises at least one opening (10) in said planar member. Inertial sensor assembly according to paragraph. 6. The assembly comprises surface features (8,1).
Inertial sensor assembly according to any one of claims 1 to 5, characterized in that it has three planar members (1,1 ') assembled orthogonally to each other by the engagement of (0,11). . 7. A solid vibration inertial sensor (2,
Inertial sensor assembly according to any one of claims 1 to 6, characterized in that it is 2 '). 8. Inertial sensor assembly according to claim 7, characterized in that each of the planar members comprises two vibration inertial sensors (2 ') arranged at right angles to each other. 9. Inertial sensor assembly according to any one of claims 1 to 8, characterized in that the sensor comprises an acceleration sensor (9). 10. Inertial sensor according to claim 1, characterized in that the sensor (2, 2 ′) is microfabricated from the material of the planar member (1, 1 ′). assembly. 11. Inertial sensor assembly according to any one of the preceding claims, characterized in that the planar member (1,1 ') is supported by associated electronics for the sensor (2,2'). . 12. The planar members (1, 1 ′) are electrically interconnected with each other at a position (7) near the intersection of the planar members. An inertial sensor assembly according to claim 1.