JP2006250583A - Vibration type gyro sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a precise and stable change in angular velocity by the optimum configuration and packaging structure of a vibration element. <P>SOLUTION: In the vibration type gyro sensor, the vibration element 20 that projects integrally in a cantilever shape from the outer-periphery section of a base section 22 and comprises a vibration terminal 23 wherein a first electrode layer 27, a second electrode layer 29 and a detection electrode 30 are laminated and formed in a longitudinal direction via a piezoelectric thin-film layer 28 is mounted on a support substrate 2 via a gold bump 25 provided at the base section 22. The vibration element 20 is formed by increasing the width of the base section 22 at least two times larger than the width dimension (t6) of a vibrator section 23 and positioning the center gravity at a region within the range of [±2×t6] to the center axis in the longitudinal direction of the vibrator section 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vibration gyro sensor including a vibration element having a cantilever vibrator.

  The gyro sensor is mounted on a video camera or the like that is likely to cause a camera shake phenomenon in a recorded image due to, for example, high zoom ratio and miniaturization, and image information on an imaging substrate such as a CCD (Charge-Coupled Device). This is used in a camera shake correction mechanism that outputs a control signal for controlling the take-in position. Further, the gyro sensor is used in a virtual reality device to constitute a motion detector, and is used in a car navigation device to constitute a direction detector.

  A video camera shake correction mechanism is also provided that performs correction by matching the positional deviation itself on the time axis of the recorded image, but in general, the rotation angle of the holding state of the video camera is set. A configuration in which an actual camera shake amount is corrected using a gyro sensor that detects and outputs a corresponding angular velocity is used. In the gyro sensor, a rotating body or optical means is used as a detection mechanism, or a vibration element is used.

  The vibration type gyro sensor is conventionally manufactured by cutting an appropriate piezoelectric material by machining and shaping it into a predetermined shape. Vibratory gyrosensors require further miniaturization and higher performance along with the reduction in the size and weight of mounted equipment and the increase in multi-functional performance. It was difficult to manufacture the element.

  For this reason, some vibration-type gyro sensors include a vibration element that forms a cantilever vibrator by stacking a pair of electrode layers on a silicon wafer with a piezoelectric thin film layer interposed therebetween using semiconductor technology. Provided (see, for example, Patent Document 1). The vibration-type gyro sensor detects a change in angular velocity due to vibration or the like by causing a vibrator to vibrate at a predetermined resonance frequency and detecting a Coriolis force generated by a change in angular velocity with a piezoelectric thin film layer and a detection electrode. The vibration-type gyro sensor has features such as a simple structure, high responsiveness by being activated in a short time, small size, and low cost.

Japanese Patent Laid-Open No. 7-113643

  By the way, in the vibration type gyro sensor, further downsizing and high performance are demanded with the reduction in size and weight of the main device to be mounted and the improvement in multifunctional performance. In the vibration type gyro sensor, the connection terminal part of the conventional vibration element and the land on the support substrate side are connected with a wire by the wire bonding method, and a space for drawing the wire around the vibration element is required and the size is small. There was a limit to conversion. In the vibration type gyro sensor, since the IC circuit elements and various electronic components constituting the drive detection circuit unit are surface-mounted by the flip chip method, the vibration elements are mounted in a separate process. There was a problem that the efficiency of the system decreased.

  In the vibration type gyro sensor, the vibration element is also provided with a metal bump on each connection terminal portion and mounted on the support substrate by the surface mounting method. The machine quality factor Q value (Q-factor) to be defined is greatly affected. In a vibration type gyro sensor, it is necessary to have a high Q value characteristic in order to obtain a highly sensitive and stable detection characteristic.

  In the vibration type gyro sensor, there has been a problem that the size of the vibration gyro sensor is greatly affected by an external load such as external vibration, and the structure for fixing the vibration element is complicated and the cost is increased. . In the vibration type gyro sensor, the installation posture and the like are determined in accordance with the specifications of the main device, so that it has versatility so that a predetermined detection characteristic can be exhibited regardless of the installation posture. There must be.

  Accordingly, an object of the present invention is to provide a vibration type gyro sensor that detects a change in angular velocity with high accuracy and stability by using an optimal configuration and mounting structure of a vibration element.

  The vibration type gyro sensor according to the present invention that achieves the above-described object includes a support substrate on which circuit elements are mounted and a wiring pattern having a plurality of lands is formed, and a cantilever-like vibrator portion is a base portion. The integrally formed vibration element is mounted. The vibration element is provided with a base portion provided with a plurality of connection terminal portions and fixed to the support substrate, and protrudes integrally in a cantilever shape from the outer peripheral portion of the base portion, and is long with each connection terminal portion as a base end. It consists of a vibrator portion in which a first electrode layer, a second electrode layer, and a detection electrode are stacked in a vertical direction via a piezoelectric thin film layer. In the vibration type gyro sensor, the vibration element has a base whose width is larger than twice the width dimension (t6) of the vibrator part and [± 2 × t6] with respect to the central axis in the longitudinal direction of the vibrator part. The center of gravity is located in a region within the range of.

  In the vibration type gyro sensor, the vibration element has a base portion with a thickness larger than 1.5 times the thickness dimension (t4) of the vibrator portion. In the vibration type gyro sensor, the vibration element welds a metal bump such as a gold bump, a copper bump, or a solder bump provided at each connection terminal portion to each opposing land, and thereby a predetermined facing to the support substrate. Implemented with spacing.

  Specifically, in the vibration type gyro sensor, each metal bump is provided with the entire center of gravity positioned in a region within the range of the width (t6) with respect to the central axis in the longitudinal direction of the vibrator portion. In the vibration type gyro sensor, each metal bump is provided in the outer region of the region of radius [2 × t6] from the base portion of the vibrator portion protruding from the base portion. In the vibration-type gyro sensor, at least one of the metal bumps is provided in a region within a range of [2 × t1] from the base portion of the vibrator portion protruding from the base portion of the thickness dimension (t1). .

  In the vibration-type gyro sensor, a natural vibration is generated in the vibrator portion by applying an alternating electric field having a predetermined frequency to the vibration element from the drive detection circuit portion. In the vibration type gyro sensor, the vibrator element is displaced by a Coriolis force generated by hand shake or the like, and the piezoelectric thin film layer detects this displacement and outputs detection signals having opposite polarities from the pair of detection electrodes. In the vibration type gyro sensor, this detection signal is processed by the drive detection circuit unit and output as an angular velocity signal.

  In the vibration type gyro sensor, the base portion has a width larger than twice the width dimension (t6) of the vibrator portion, and within a range of [± 2 × t6] with respect to the central axis in the longitudinal direction of the vibrator portion. By providing the vibration element formed by locating the center of gravity in this region, the vibrator section that vibrates in the thickness direction can perform a vibration operation in a stable state without losing the left and right balance. Therefore, in the vibration type gyro sensor, the detection signal based on the displacement of the vibrator portion due to the Coriolis force caused by the hand shake or the like becomes a stable level without losing the left and right balance, so that the hand shake and the like can be detected with high accuracy. Become.

  In the vibration type gyro sensor, the base has a vibration element formed with a thickness larger than 1.5 times the thickness dimension (t4) of the vibrator portion, so that the mechanical rigidity of the base is maintained and the support substrate is provided. It is firmly fixed and prevents the occurrence of vibration operation accompanying the vibration operation of the vibrator section. In the vibration type gyro sensor, the occurrence of deviation of the resonance frequency of the vibrator part due to the vibration of the base part is suppressed, and the vibration part performs a vibration operation in a stable state to detect high-precision camera shake or the like. Will come to be.

  In the vibration type gyro sensor, the vibration element has each metal bump provided with the entire center of gravity positioned in a region within the range of the width (t6) of the vibrator portion with respect to the central axis in the longitudinal direction of the vibrator portion. By fixing the base portion to the support substrate, the vibrator portion that vibrates in the thickness direction can be oscillated in a stable state without losing the left-right balance.

  In the vibration type gyro sensor, the vibration element fixes the base portion to the support substrate via each metal bump provided in the outer region of the radius [2 × t6] from the base portion of the vibrator portion protruding from the base portion. Thus, the action of absorbing the vibration of the vibrator portion by each metal bump for reducing the Q value is reduced. In the vibration type gyro sensor, the reduction of the Q value is suppressed, and high-precision camera shake and the like are detected.

  In the vibration-type gyro sensor, the vibration element has each metal bump provided in a region within a range of [2 × t1] from the root portion of the vibrator portion protruding from the base portion of the thickness dimension (t1). By fixing the base to the support substrate via the base, the occurrence of the vibration of the base accompanying the vibration of the vibrator is prevented. In the vibration type gyro sensor, the vibrator unit performs the vibration operation in a stable state while suppressing the occurrence of the resonance frequency deviation due to the vibration operation of the base so that high-precision camera shake or the like can be detected. Become.

  According to the vibration type gyro sensor of the present invention, the vibration element having the optimum shape of the base portion and the cantilever-like vibrator portion that detects the detection signal is mounted on the support substrate in an optimized manner. Therefore, the structure can be simplified and miniaturized, and the vibrator unit can stably and highly accurately oscillate to detect a highly accurate and stable change in angular velocity.

  Hereinafter, the vibration type gyro sensor 1 shown in the drawings as an embodiment of the present invention will be described in detail. As shown in FIG. 1, the vibration type gyro sensor 1 includes an outer appearance member including a support substrate 2 and a cover member 15 that is assembled on the main surface 2-1 of the support substrate 2 and constitutes the component mounting space portion 3. For example, it is mounted on a video camera to constitute a camera shake correction mechanism. The vibration gyro sensor 1 is used for a virtual reality device to constitute an operation detector, or used for a car navigation device to constitute a direction detector.

  In the vibration gyro sensor 1, for example, a ceramic substrate or a glass substrate is used as the support substrate 2, and a predetermined wiring pattern 5 having a large number of lands 4 is formed on the main surface 2-1 though details are omitted. Thus, a component mounting area 6 is configured. The support substrate 2 is connected to each land 4 and has a pair of vibration elements 20X and 20Y, which will be described in detail later on the main surface 2-1, (hereinafter collectively referred to as the vibration element 20 unless otherwise described). In addition, an IC circuit element 7 or a large number of external ceramic capacitors and appropriate electronic components 8 are mounted.

  The vibration type gyro sensor 1 detects the displacement of the vibration element 20 due to the Coriolis force generated by hand shake or the like by the piezoelectric thin film layer 28 formed on the piezoelectric element 20 and the detection electrode 30 as will be described in detail later, and outputs a detection signal. Output. In the vibration type gyro sensor 1, when the piezoelectric thin film layer 28 is irradiated with light, a voltage is generated due to the pyroelectric effect, and this pyroelectric voltage affects the detection operation and the detection characteristics are deteriorated.

  In the vibration type gyro sensor 1, the component mounting space 3 is shielded from light by the support substrate 2 and the cover member 15, and the characteristic deterioration due to the influence of external light is prevented. As shown in FIG. 1, the support substrate 2 has a light shielding step portion 9 formed of a vertical wall, the outer peripheral portion being stepped down from the main surface 2-1 so as to rim the component mounting region. A cover fixing part 10 is formed. In the vibration type gyro sensor 1, the component mounting space 3 is hermetically sealed by bonding a cover member formed of a thin metal plate to the support substrate 2 over the entire periphery of the cover fixing portion 9 with adhesive resin. It is dust-proof and moisture-proof and constitutes a light shielding space.

  As shown in FIG. 1, the cover member 15 has a main surface portion 16 having an outer dimension sufficient to cover the component mounting region 6 of the support substrate 2, and is bent integrally around the outer periphery of the main surface portion 16 over the entire periphery. The entire outer peripheral wall portion 17 is formed in a box shape. The cover member 15 has a height dimension that constitutes the component mounting space portion 3 in which the vibrator portion 23 of the vibration element 20 can perform a vibration operation in a state where the outer peripheral wall portion 17 is assembled to the support substrate 2. Is formed. In the cover member 15, an outer peripheral flange portion 18 having a slightly smaller width than the cover fixing portion 10 formed on the support substrate 2 is integrally bent at the opening edge of the outer peripheral wall portion 17 over the entire periphery. . Although not shown, the cover member 15 is formed with a ground convex portion on the outer peripheral flange portion, and is connected to the ground in a state where the vibration type gyro sensor 1 is mounted on a mounting board or the like.

  The cover member 15 is formed of a thin metal plate so that the vibration-type gyro sensor 1 can be kept small and light. However, the cover member 15 has a sufficient light shielding function because the light shielding property against external light having an infrared wavelength is reduced. Sometimes you don't get it. Therefore, the cover member 15 is coated with, for example, an infrared absorbing paint that absorbs light of an infrared wavelength on the entire surface of the main surface portion 16 and the outer peripheral flange portion 42 to form the light shielding layer 19, and the cover member 15 enters the component mounting space portion 3. The vibration element 20 performs a stable operation by shielding the radiation of external light having an infrared wavelength. The cover member 15 is formed by dipping the light shielding layer 19 in the infrared absorbing paint solution to form the front and back main surfaces, or by performing black chrome plating treatment, black dyeing treatment or black alumite (registered trademark) treatment. May be.

  In the vibration type gyro sensor 1, the cover member 15 is assembled to the support substrate 2 by superimposing the outer peripheral flange portion 18 on the cover fixing portion 10 and joining them with an adhesive, and is sealed and shielded from light. The space part 3 is configured. However, in the vibration type gyro sensor 1, external light enters the component mounting space 3 through the adhesive layer interposed in the gap between the overlapped cover fixing portion 10 and the outer peripheral flange portion 18. In the vibration type gyro sensor 1, as described above, the support substrate 2 is formed by stepping the cover fixing portion 10 with respect to the main surface 2-1 through the light shielding step portion 9, so that the outside that has passed through the adhesive layer is transmitted. The light is shielded by the light shielding step 9.

  In the vibration type gyro sensor 1, the cover member 15 is assembled to the support substrate 2 by the surface mounting method in the same manner as the other constituent members, so that the assembly process can be rationalized. In the vibration type gyro sensor 1, the cover member 15 is fixed on the cover fixing portion 10 that has been dropped from the support substrate 2, so that the thickness can be reduced and the adhesive material can be prevented from flowing into the component mounting region 6. The In the vibration type gyro sensor 1, the component mounting space portion 3 is configured as a dust-proof and moisture-proof space portion and also as a light-shielding space portion, thereby suppressing the generation of the pyroelectric effect in the vibration element 20 and stable camera shake. And so on.

  In the vibration type gyro sensor 1, the support substrate 2 and the cover member 15 are not limited to the assembly structure described above, and an appropriate assembly structure is employed. In the vibration type gyro sensor 1, for example, a frame-like cover fitting groove is formed on the main surface 2-1 of the support substrate 2 so as to surround the component mounting region 6, and the opening edge of the outer peripheral wall portion 17 is formed in this cover fitting groove. The cover member 15 may be assembled by fitting and fixing with an adhesive. Further, in the vibration type gyro sensor 1, for example, a frame-shaped light-shielding convex portion is integrally formed on the main surface 2-1 of the support substrate 2 so as to surround the component mounting region 6, and a cover member is formed at an outer peripheral portion of the light-shielding convex portion. Fifteen outer peripheral flange portions 18 may be joined.

  The support substrate 2 mounts the vibration element 20 together with the IC circuit element 7 and the electronic component 8 on the component mounting region 6 by a surface mounting method such as a flip chip method using an appropriate mounting machine. The support substrate 2 has a pair of vibration elements 20X and 20Y formed in the same shape as described in detail later, positioned at opposite corner portions 2C-1 and 2C-2 of the main surface 2-1, and having different axes. And implement. Although not described in detail, the support substrate 2 is positioned and placed on the mounting machine, and the position of each land 4 is recognized by the mounting machine side. As will be described in detail later, the vibration element 20 is mounted on the support substrate 2 with the mounting position specified by the mounting machine.

  The support substrate 2 is formed with interval configuration recesses 11A and 11B (hereinafter collectively referred to as interval configuration recesses 11 unless otherwise described) in the component mounting region 6 corresponding to the vibration elements 20X and 20Y. Yes. The spacing component recess 11 is formed with a predetermined depth and opening size by, for example, etching or grooving the main surface 2-1 of the support substrate 2.

  As will be described in detail later, the vibration type gyro sensor 1 is supported by a vibration element 20 in which a base 22 and a cantilever-like vibrator 23 are integrally formed with a silicon substrate 21 as a base material through gold bumps 26. It is mounted on the main surface 2-1 of the substrate 2. In the vibration element 20, the distance between the vibrator portion 23 and the main surface 2-1 of the support substrate 2 is defined by the thickness of the gold bump 26. Cannot be held.

  The vibration element 20 generates an air flow with the main surface 2-1 of the support substrate 2 in accordance with the vibration operation of the vibrator unit 23, and this air flow hits the main surface 2-1 of the support substrate 2 to generate a vibrator. It receives the action of a damping effect that pushes up the portion 23. As shown in FIG. 2, the vibration-type gyro sensor 1 is affected by the damping effect that acts on the vibration element 20 by forming the spacing component recess 11 on the main surface 2-1 of the support substrate 2 as described above. The main surface 2-1 and the vibrator portion 23 are held at a sufficient distance so as to be reduced.

  In the vibration type gyro sensor 1, the gap forming recess 11 is optimized and formed on the support substrate 2 in accordance with the size of the vibrator portion 23 of the vibration element 20. In the vibration type gyro sensor 1, when the vibration element 20 is formed with a dimension value to be described later and the maximum amplitude amount of the vibrator portion 23 is p, the opening 11 has an opening dimension of 2.1 mm × 0.32 mm. And the depth dimension k is formed such that k ≧ p / 2 + 0.5 (mm). In the vibration type gyro sensor 1, by forming the gap-constituting recess 11 on the support substrate 2, the height dimension can be suppressed and the thickness can be reduced, and the influence of the damping effect on the vibration element 20 can be reduced. A high-sensitivity and stable camera shake detection operation is performed such that the Q value is maintained.

  In the present specification, each part is described with specific dimension values, but only the center reference value is shown for each dimension value. Each part is not limited to be formed with a dimension value limited to the central reference value, and is of course formed with a dimension value in a general tolerance range.

  In the vibration type gyro sensor 1, each vibration element 20X, 20Y is formed on the basis of a silicon single crystal substrate 21 (hereinafter abbreviated as a silicon substrate 21) as will be described in detail later, as shown in FIG. Mounted on the main surface 2-1 of the support substrate 2 in a state shifted by 90 ° from each other. The vibration element 20 will be described in detail later. As shown in FIGS. 2 and 3, as shown in FIGS. 2 and 3, the base 22 is formed in a rectangular block shape with a slightly thick cross section having a deformed pentagonal shape, and one side of the base 22. And a vibrator portion 23 integrally projecting from the portion.

  In the vibration element 20, the second main surface of the base 22 constituted by the second main surface 21-2 of the silicon substrate 21 constitutes a fixed surface with respect to the support substrate 2 as will be described later. Although details are omitted on the second main surface of the base 22, the vibration element 20 includes a first terminal portion 25 </ b> A to a fourth terminal portion 25 </ b> D (hereinafter, unless otherwise described) via a planarization layer 24. The first gold bumps 26A to the fourth gold bumps 26D (hereinafter collectively referred to as gold bumps 26 unless otherwise described) are formed on the terminal portions 25. Is formed.

  The vibration element 20 is formed so that each terminal portion 25 corresponds to each land 4 formed on the wiring pattern 5 on the support substrate 2 side. As will be described in detail later, the terminal portion 25 and the land 4 which are opposed to each other are formed. The alignment is combined with the support substrate 2. In this state, the vibration element 20 applies the ultrasonic wave to the gold bumps 26 while being pressed against the support substrate 2 to perform welding, thereby joining the terminal portions 25 and the lands 4 to each other on the support substrate 2. To be implemented. The vibration element 20 is mounted via the gold bumps 26 having a predetermined height, so that the vibrator unit 23 has a second main surface of the vibration element 20 with respect to the main surface 2-1 of the support substrate 2 as described above. It is held at the height position of so that it can be vibrated.

  The vibration element 20 is provided with a gold bump 26 on the terminal portion 25 within a range satisfying the following conditions as will be described in detail by an analysis description to be described later, and the base portion 22 is fixed on the main surface 2-1 of the support substrate 2. So that That is, in the vibration element 20, each gold bump 26 is provided with the entire center of gravity positioned in a region within the range of the width dimension t <b> 6 of the vibrator portion 23 with respect to the central axis C in the longitudinal direction of the vibrator portion 23. Like that.

  Further, in the vibrating element 20, each gold bump 26 has a radius r that is twice the width dimension t6 of the vibrator portion 23 from the root portion 43 (see FIG. 17) of the vibrator portion 23 protruding from the base portion 22. It is arranged to be located outside the area.

  Further, the vibration element 20 is configured such that at least one of the gold bumps 26 is located in a region twice the thickness dimension t1 of the base portion 22 from the root portion 43 of the vibrator portion 23 protruding from the base portion 22. Provided.

  In the resonator element 20, the vibrator portion 23 has the second main surface of the base portion 22, that is, the second main surface constituted by the second main surface 21-2 of the silicon substrate 21 and the second main surface of the base portion 22. The one end is integrated with the base portion 22 and protrudes in a cantilever shape. The vibration element 20 has a predetermined thickness as the vibrator portion 23 is stepped down from the first main surface of the base portion 22 constituted by the first main surface 21-1 of the silicon substrate 21 on the first main surface side. The The vibration element 20 is configured by a rectangular cantilever in which the vibrator portion 23 has a predetermined length and a cross-sectional area and is integrally formed with the base portion 22.

  As shown in FIG. 5, the vibration element 20 includes a base portion 22 having a thickness dimension t <b> 1 of 300 μm, a length dimension t <b> 2 to the tip of the vibrator section 23 of 3 mm, and a width dimension t <b> 3. Is formed with a size of 1 mm. As shown in FIG. 6, the resonator element 23 is formed with a thickness dimension t4 of 100 μm, a length dimension t5 of 2.5 mm, and a width dimension t6 of 100 μm. As will be described in detail later, the vibration element 20 vibrates with a drive voltage of a predetermined frequency applied from the drive detection circuit unit 50, but vibrates at a resonance frequency of 40 KHz from the above-described shape. In addition, the vibration element 20 is not limited to such a configuration, and variously set according to a frequency to be used and a target overall shape.

  In the vibration element 20, the base portion 22 and the vibrator portion 23 are formed with the above-described specific dimension values, and are appropriately set within a range that satisfies the following conditions as will be described in detail by an analysis description to be described later. To be formed. That is, the vibration element 20 is formed such that the base portion 22 has a width dimension t3 larger than at least twice the width dimension t6 of the vibrator portion 23. The vibration element 20 is formed such that the base portion 22 has the center of gravity G located in a region within a range of [± 2 × t6] with respect to the central axis C in the longitudinal direction of the vibrator portion 23. Further, in the vibration element 20, the base portion 22 is formed with a thickness dimension t 1 of at least 1.5 times the thickness dimension t 4 of the vibrator portion 23.

  As shown in FIGS. 2 and 3, the vibrating element 20 is formed on the second main surface of the vibrator portion 23 over the substantially entire length in the longitudinal direction by a vibrating element manufacturing process described later. An electrode layer 27, a piezoelectric thin film layer 28, and a drive electrode layer (second electrode layer) 29 are stacked. The vibration element 20 has a pair of detection electrodes 30R and 30L on the second main surface of the vibrator portion 23 with the drive electrode layer 29 interposed therebetween (hereinafter collectively referred to as the detection electrode 30 unless otherwise described). ) Are laminated. In the vibration element 20, a reference electrode layer 27 is formed as a first layer on the second main surface of the vibrator unit 23, and a piezoelectric thin film layer 28 having substantially the same length is stacked on the reference electrode layer 27. The vibration element 20 is formed by laminating a drive electrode layer 28 having substantially the same length and width on the piezoelectric thin film layer 28 so as to be positioned at the center in the width direction, and sandwiching the drive electrode layer 2. A pair of detection electrodes 30R and 30L are stacked on top of each other.

  In the vibration element 20, as shown in FIG. 3, a first lead 31 </ b> A that connects the reference electrode layer 27 and the first terminal portion 25 </ b> A is formed on the second main surface of the base 22, and the drive electrode layer 29. A third lead 31C that connects the first terminal portion 25C and the third terminal portion 25C is formed. The vibration element 20 includes a second lead 31B that connects the first detection electrode 25R and the third terminal portion 25C, and a fourth lead 31D that connects the second detection electrode 30L and the fourth terminal portion 25D. Is formed. The leads 31A to 31D are hereinafter collectively referred to as leads 31 except when individually described.

  The first lead 31A is integrally extended from the base end portion of the reference electrode layer 27 formed on the vibrator portion 23 to the base portion 22 side, and on the second main surface of the base portion 22, as shown in FIG. Are integrated with the first terminal portion 25 </ b> A formed at one corner portion on the side formed integrally. Although the details of the drive electrode layer 29 and the detection electrode 30 are omitted, the base end portions of the drive electrode layer 29 and the detection electrode 30 are integrally extended from the vibrator portion 23 to the base portion 22 by a slightly wide portion, and these wide portions are covered with the planarizing layer 24. The

  The second lead 31B is formed so that one end portion thereof passes over the planarization layer 24, and is guided along the one side portion of the base portion 22 to the rear corner portion facing the first terminal portion 25A. The second terminal portion 25B formed at the corner portion is connected. The third lead 31C is formed so that one end thereof gets over the flattening layer 24, is guided to the rear side across the substantially central portion of the base portion 22, and faces the second terminal portion 25B along the rear end side. By being led to the corner portion to be connected, it is connected to the third terminal portion 25C formed at this corner portion. The fourth lead 31D is also formed so that one end of the fourth lead 31D extends over the planarization layer 24, and the other of the front side facing the first terminal portion 25A along the other side portion of the base 22 facing the second lead 31B. By being led to the corner portion, it is connected to the fourth terminal portion 25D formed in this corner portion.

  Note that, in the vibration element 20, the terminal portions 25 are formed on the second main surface of the base portion 22 at an appropriate position and in an appropriate number regardless of the configuration described above. In addition, in the vibration element 20, the connection pattern between the lead 31 of each electrode layer and the terminal portion 25 is not limited to the configuration described above, and the base portion 22 depends on the position and number of the terminal portions 25. The second main surface is appropriately formed.

  In the vibration element 20, the gold bumps 26 are formed on the respective terminal portions 25. However, the gold bumps 26 may be formed by so-called two-stage bumps. In addition, the vibration element 20 may be formed with a so-called dummy fifth gold bump that does not perform electrical connection on the second main surface of the base portion 22. Of course, a dummy terminal part to which the fifth gold bump is welded and fixed is formed on the support substrate 2 side.

  In the vibration type gyro sensor 1, the Q value is determined by the structure in which the vibration element 20 is fixed to the support substrate 2. In the vibration type gyro sensor 1, the mounting process is made more efficient by mounting the vibration element 20 on the support substrate 2 by the surface mounting method. In the surface mounting method, not only the gold bumps 26 described above but also various metal bumps such as solder balls and copper bumps are used as connectors. The vibration type gyro sensor 1 is generally employed in a semiconductor process, and a gold bump 26 having high heat resistance is employed as a connector because reflow soldering or the like is performed in a device mounting process.

  In the vibration element 20, the base 22 is mounted in a state of floating from the main surface 2-1 of the support substrate 2 via the gold bumps 26, so that, for example, compared with a case where the entire surface of the base 22 is joined by a gold connection layer. As a result, the attenuation rate of the tip of the vibrator portion 23 is increased, and a good Q value can be obtained. Further, in the vibration element 20, a good Q value characteristic is obtained by a structure in which the base portion 22 is fixed at a plurality of locations rather than being fixed at one location with respect to the main surface 2-1 of the support substrate 2. In the vibration element 20, good Q-value characteristics are obtained by fixing the base 22 to the four corner positions with respect to the main surface 2-1 of the support substrate 2.

  In the vibration type gyro sensor 1, the two vibration elements 20 </ b> X and 20 </ b> Y are positioned at the opposite corner portions 2 </ b> C- 1 and 2 </ b> C- 2 of the support substrate 2 and mounted with different axes as described above. In the vibration type gyro sensor 1, as shown in FIG. 1, the first vibration element 20X fixes the base 22 on the main surface 2-1 of the support substrate 2 via the gold bump 26 described above at the corner portion 2C-1. Then, the vibrator portion 23 integrally projected from the base portion 22 is directed to the adjacent corner portion 2 </ b> C- 3 along the side edge of the support substrate 2.

  In the vibration gyro sensor 1, the second vibration element 20 </ b> Y is fixed on the main surface 2-1 of the support substrate 2 through the gold bump 26 described above at the corner portion 2 </ b> C- 2. The integrally projecting transducer portion 23 is directed along the side edge of the support substrate 2 to the adjacent corner portion 2C-3. In the vibration-type gyro sensor 1, the first vibration element 20X and the second vibration element 20Y are provided with an angle of 90 ° with the respective vibrator portions 23 facing each other toward the corner portion 2C-3, and the support substrate 2 respectively. To be implemented.

  In the vibration type gyro sensor 1, in order to precisely position and mount the first vibration element 20X and the second vibration element 20Y having the same shape with respect to the support substrate 2, the support substrate 2 is provided with each land as described above. The position of 4 is recognized by the mounting machine side. In order to be positioned and mounted on each land 4 recognized by the mounting machine, the vibration element 20 is positioned on the base 22 with alignment marks 32A and 32B (hereinafter collectively referred to as alignment marks 32). Is provided).

  As shown in FIGS. 1 and 3, the vibration element 20 includes a pair of rectangular portions made of metal foil or the like that are formed on the first main surface of the base portion 22 so as to be spaced apart from each other in the width direction. Composed. The vibration element 20 is configured such that the positioning mark 32 is read by the mounting machine, and mounting data of the position and orientation with respect to the support substrate 2 is generated. The vibration element 20 is precisely positioned and mounted on the support substrate 2 based on the mounting data and the data of the land 4 described above.

  The vibration element 20 has the alignment mark 32 formed on the first main surface of the base 22, but is not limited to this configuration. The alignment mark 32 is formed on the second main surface of the base portion 22 at an appropriate position avoiding the terminal portion 25 and the lead 31 in the same process as the wiring process. Also good. The alignment mark 32 is a reference marker used in the reactive ion etching process by the inductively coupled plasma apparatus used in the outer groove forming process for forming the electrode layer of the vibration element 20 and the vibrator portion 23 as will be described in detail later. It is preferable to be positioned and formed according to the above. The alignment mark 32 can be formed with an accuracy of 0.1 m or less with respect to the vibrator portion 23 by using a stepper exposure apparatus.

  The alignment mark 32 is formed by an appropriate method. For example, when it is formed by patterning the first electrode layer 40 composed of a titanium layer and a gold layer on the second main surface of the base portion 22 as described later, When reading is performed in the mounting process and image processing is performed, a good contrast is obtained, and mounting accuracy is improved.

  In the vibration type gyro sensor 1, each vibration element 20 detects the angular velocity in one direction applied to the longitudinal direction generated in the vibrator section 23 having a rectangular cross section as described above. In the vibration type gyro sensor 1, the first vibration element 20 </ b> X and the second vibration element 20 </ b> Y are mounted on the support substrate 2 at different angles, thereby simultaneously detecting the angular velocities in the X-axis direction and the Y-axis direction. The vibration type gyro sensor 1 outputs a control signal based on a vibration state caused by a camera shake by the first vibration element 20X and the second vibration element 20Y mounted with different axes, and constitutes a camera shake correction mechanism.

  The vibration type gyro sensor 1 is connected to the first vibration element 20X and the second vibration element 20Y, respectively, and is configured by an IC circuit element 7, an electronic component 8, and the like, for example, a first drive detection circuit unit 50X shown in FIG. 2 drive detection circuit unit 50Y. Since the first drive detection circuit unit 50X and the second drive detection circuit unit 50Y have the same circuit configuration, the vibration type gyro sensor 1 will be hereinafter collectively referred to as the drive detection circuit unit 50. The drive detection circuit unit 50 includes an impedance conversion circuit 51, an addition circuit 52, an oscillation circuit 53, a differential amplification circuit 54, a synchronous detection circuit 55, a DC amplification circuit 56, and the like.

  As shown in FIG. 4, in the drive detection circuit unit 50, an impedance conversion circuit 51 and a differential amplification circuit 54 are connected to the first detection electrode 30 </ b> R of the vibration element 20. In the drive detection circuit unit 50, an addition circuit 52 is connected to the impedance conversion circuit 51, and an oscillation circuit 53 connected to the addition circuit 52 is connected to the second detection electrode 30L. In the drive detection circuit unit 50, a synchronous detection circuit 55 is connected to the differential amplifier circuit 54 and the oscillation circuit 53, and a DC amplifier circuit 56 is connected to the synchronous detection circuit 55. The reference electrode layer 27 of the vibration element 20 is connected to the reference potential 57 on the support substrate 2 side.

  In the drive detection circuit unit 50, the vibration element 20, the impedance conversion circuit 51, the addition circuit 52, and the oscillation circuit 53 constitute a self-excited oscillation circuit, and drive electrodes formed on the vibrator unit 23 of the vibration element 20 from the oscillation circuit 53. By applying an oscillation output Vg0 having a predetermined frequency to the layer 29, a natural vibration is generated. In the drive detection circuit unit 50, the output Vgr from the first detection electrode 30R and the output Vgl from the second detection electrode 30L of the vibration element 20 are supplied to the impedance conversion circuit 51, and the impedance conversion circuit 51 is based on these inputs. Output Vzr and Vzl to the adder circuit 52, respectively. The drive detection circuit unit 50 feeds back the addition output Vsa from the addition circuit 52 to the oscillation circuit 53 based on these inputs.

  In the drive detection circuit unit 50, the output Vgr from the first detection electrode 30 </ b> R of the vibration element 20 and the output Vgl from the second detection electrode 30 </ b> L are supplied to the differential amplifier circuit 54. The drive detection circuit unit 50 obtains a predetermined output Vda by the differential amplifier circuit 54 because a difference occurs between the output Vgr and the output Vgl in a state where the vibration element 20 detects a hand shake as will be described later. In the drive detection circuit unit 50, the output Vda from the differential amplifier circuit 54 is supplied to the synchronous detection circuit 55. The drive detection circuit unit 50 synchronously detects the output Vda in the synchronous detection circuit 55 to convert the output Vda into a DC signal Vsd and supply the DC signal Vsd to the DC amplifier circuit 56, and outputs a DC signal Vsd that has been subjected to predetermined DC amplification.

  The drive detection circuit unit 50 integrates the synchronous detection circuit 55 after full-wave rectifying the output Vda of the differential amplifier circuit 54 at the timing of the clock signal Vck output from the oscillation circuit 53 in synchronization with the drive signal. To obtain a DC signal Vsd. As described above, the drive detection circuit unit 50 amplifies the DC signal Vsd in the DC amplifier 14 and outputs the amplified signal to detect an angular velocity signal caused by camera shake.

  The drive detection circuit unit 50 is configured to obtain a low impedance output z3 when the impedance conversion circuit 51 is in a high impedance input z2, and adds to the impedance z1 between the first detection electrode 30R and the second detection electrode 30L. There exists an effect | action which isolate | separates impedance z4 between the inputs of the circuit 52. FIG. In the drive detection circuit unit 50, it is possible to obtain a large output difference from the first detection electrode 30R and the second detection electrode 30L by providing the impedance conversion circuit 51.

  In the drive detection circuit unit 50, the impedance conversion circuit 51 described above performs an impedance conversion function between input and output, and does not affect the magnitude of the signal. Accordingly, in the drive detection circuit unit 50, the output Vgr from the first detection electrode 30R, the output Vzr on one side of the impedance conversion circuit 51, the output Vgl from the second detection electrode 30L, and the output on the other side of the impedance conversion circuit 51 Vzl is the same size. In the drive detection circuit unit 50, even if there is a difference between the output Vgr from the first detection electrode 30 </ b> R and the output Vgl from the second detection electrode 30 </ b> L due to hand vibration detection by the vibration element 20, It is held at the output Vsa.

  In the drive detection circuit unit 50, the noise component superimposed on the output Vgo of the oscillation circuit 53 is equivalent to the band filter in the vibration element 20, even if noise is superimposed due to, for example, a switching operation or the like. By removing components other than those, it is possible to obtain a highly accurate output Vda from which noise components have been removed from the differential amplifier circuit 54. The vibration-type gyro sensor 1 is not limited to the drive detection circuit unit 50 described above, and a displacement due to a hand movement operation of the vibration element unit 23 that vibrates naturally is detected by the piezoelectric thin film layer 28 and the pair of detection electrodes 30. The detection output may be obtained by performing an appropriate process.

  As described above, the vibration type gyro sensor 1 includes the first vibration element 20X that detects the angular velocity in the X-axis direction and the second vibration element 20Y that detects the angular velocity in the Y-axis direction. In the vibration type gyro sensor 1, the detection output VsdX in the X-axis direction is obtained from the first drive detection circuit unit 50X connected to the first vibration element 20X, and the second drive detection circuit connected to the second vibration element 20Y. A detection output VsdY in the Y-axis direction is obtained from the unit 50Y. In the vibration type gyro sensor 1, the two vibration elements 20 are precisely mounted on one support substrate 2 with different axes 23, thereby simplifying the structure and reducing the size. The detection operation in the biaxial direction can be performed with high accuracy.

  In the vibration type gyro sensor 1, the vibration element 20 described above includes, for example, as shown in FIGS. 7 and 8, the azimuth plane of the main surface 21-1 is the (100) plane and the azimuth plane of the side surface 21-3 is (110). ) After a large number of silicon substrates 21 cut out to form a surface are formed as a base material, they are cut into pieces one after another through a cutting process. Note that the silicon substrate 21 is cut into a predetermined size in a state where the vibration element 20 is completed, but for the sake of convenience of explanation, the same reference numerals are given to large materials.

  The outer dimensions of the silicon substrate 21 are appropriately determined according to the equipment specifications used in the process, and are set to, for example, 300 × 300 (mm). The thickness dimension of the silicon substrate 21 is determined depending on workability, cost, and the like, but may be a thickness that is at least larger than the thickness dimension of the base portion 22 of the vibration element 20. As described above, since the thickness of the base portion 22 is 300 μm and the thickness of the vibrator portion 23 is 100 μm, the silicon substrate 21 is a 300 μm substrate.

  As the silicon substrate 21, a substantially pure single crystal silicon substrate that is not subjected to doping treatment or a single crystal silicon substrate having a volume resistivity of 100Ω · cmm as described later is used. By using such a single crystal silicon substrate, the silicon substrate 21 has a high resistance value characteristic.

The silicon substrate 21 is subjected to a thermal oxidation process, and as shown in FIG. 8, silicon oxide films (SiO ₂ films) 33A and 33B (on the first main surface 21-1 and the second main surface 21-2, respectively). Hereinafter, the silicon oxide film 33 is generically formed unless otherwise described). As will be described later, the silicon oxide film 33 functions as a protective film when the silicon substrate 21 is subjected to crystal anisotropic etching.

  In the vibration element manufacturing process, an opening is formed by removing the vibration element formation portion corresponding to the formation region of each vibration element 20 from the silicon oxide film 33A formed on the first main surface 21-1 of the silicon substrate 21. The process to perform is given. In the vibration element manufacturing process, a photoresist layer 34 is formed over the entire surface of the silicon oxide film 33A of the silicon substrate 21 by using, for example, a photosensitive photoresist material. Similar to the semiconductor process, the photoresist layer 34 is formed of a photosensitive resin after a pre-baking process for removing moisture by heating the silicon oxide film 33A with microwaves.

  In the vibration element manufacturing process, the photoresist layer 34 is exposed and developed in a state in which the photoresist layer 34 is masked with each vibration element forming portion as an opening. Through these steps, the vibration element manufacturing process removes the photoresist layer 34 corresponding to the vibration element forming portion and exposes the silicon oxide film 33A to the outside as shown in FIGS. A portion 35 is formed. In the silicon substrate 21, as shown in FIG. 9, 3 × 5 photoresist layer openings 35 are formed, so that 15 vibration elements 20 are collectively formed.

  In the vibration element manufacturing process, after removing the photoresist layer 34, a first etching process is performed to remove the silicon oxide film 33 </ b> A exposed to the photoresist layer opening 35, and the vibration element 20 is applied to the silicon substrate 21. A second etching process for forming a portion corresponding to the vibrator portion 23 is performed. The first etching process employs a wet etching method in which only the silicon oxide film 33A is removed in order to maintain the smoothness of the interface of the silicon substrate 21, but is not limited to this method. For example, an ion etching method or the like is used. The appropriate etching process may be used.

  In the first etching process, for example, an ammonium fluoride solution is used as an etchant, and the silicon oxide film 33A is removed to form a silicon oxide film opening 36, thereby forming a silicon substrate as shown in FIGS. The 21st main surface 21-1 of 21 is made to face outward. In the first etching process, when etching is performed for a long time, a so-called side etching phenomenon occurs in which the etching proceeds from the side surface of the silicon oxide film opening 36, and therefore, when the silicon oxide film 33A is etched. It is preferable to accurately manage the etching time so that the process ends.

  The second etching process is a process in which the silicon substrate 21 exposed outward from the silicon oxide film opening 36 is etched to the thickness of the vibrator portion 23, and the etching rate depends on the crystal direction of the silicon substrate 21. The crystal anisotropic wet etching is used. In the second etching process, for example, TMAH (tetramethylammonium hydroxide), KOH (potassium hydroxide), or EDP (ethylenediamine-pyrocatechol-water) solution is used as an etchant. Specifically, in the second etching process, a TMAH 20% solution that increases the etching rate selectivity of the silicon oxide films 33A and 33B on the front and rear surfaces is used as an etchant, and the temperature is raised to 80 ° C. while stirring the etchant. Kept for 6 hours etching.

  In the second etching process, the silicon substrate 21 has a surface orientation of an angle of about 55 ° with respect to the (100) plane due to the low etching resistance of the side surface 21-3 with respect to the first main surface 21-1. A (110) plane appears, and a rectangular recess 37 having a predetermined size and shape is formed on the first main surface 21-1 of the silicon substrate 21 as shown in FIGS. In the second etching process, the thickness of the silicon substrate 21 exposed to the silicon oxide film opening 36 is etched until the thickness of the vibrator portion 23 is reached, thereby forming a so-called diaphragm portion 38 shown in detail in FIG. .

  The rectangular recess 37 has an opening dimension of a length dimension t8 and a width dimension t9 as shown in FIG. 13, and is formed with a depth dimension t10 as shown in FIG. As shown in FIG. 15, the rectangular concave portion 37 forms a trapezoidal space section whose opening size gradually decreases from the first main surface 21-1 toward the second main surface 21-2 side. As described above, the rectangular recess 37 is formed with an inclination angle θ of 55 ° inwardly descending as described above. The diaphragm portion 38 is defined by a width dimension t6 and a length dimension t5 of the vibrator portion 23 and a width dimension t7 (see FIG. 28) of an outer groove 39 which will be formed on the outer peripheral portion as will be described later. The outer groove 39 is required to have a width dimension t7 (depth dimension t10 × 1 / tan 55 °).

  Therefore, the rectangular recess 37 has an opening width dimension t9 that defines the width of the diaphragm section 38, from (t10 × 1 / tan 55 °) × 2 + t6 (width dimension of the vibrator section 23) + 2 × t7 (slit width dimension). Desired. When the width t9 of the rectangular recess 34 is t10 = 200 μm, t6 = 100 μm, and t7 = 200 μm, t9 = 780 μm.

  By performing the second etching process described above, the silicon substrate 21 is formed with a rectangular recess 37 whose inner wall is configured as an inclined surface having an inclination angle of 55 ° in the length direction as in the width direction. Therefore, the rectangular recess 37 has a length dimension t8 that defines the length of the diaphragm section 38, from (t10 × 1 / tan 55 °) × 2 + t5 (length dimension of the vibrator section 23) + t7 (width dimension of the slit). Desired. When the length t8 of the rectangular recess 37 is t10 = 200 μm, t5 = 2.5 mm, and t7 = 200 μm, t8 = 2980 μm.

  In the vibration element manufacturing process, the vibrator unit 23 is configured to have a predetermined thickness between the bottom surface of the rectangular recess 37 and the second main surface 21-2 on the silicon substrate 21 through the above-described steps. A rectangular diaphragm portion 38 shown in FIG. In the vibration element manufacturing process, an electrode forming process is performed with the second main surface 21-2 side of the diaphragm portion 38 as a processed surface. The electrode forming step is performed by, for example, using a magnetron sputtering apparatus, the first electrode layer 40 constituting the reference electrode layer 27 on the second main surface 21-2 via the silicon oxide film 33B as shown in FIG. A piezoelectric film layer 41 constituting the layer 28 and a second electrode layer 42 constituting the drive electrode layer 29 and the detection electrode 30 are laminated.

  In the vibration element manufacturing process, each lead 31 and terminal part 25 is formed on the formation part of the base 22 in accordance with the above-described formation process of the first electrode layer 40 and the formation process of the second electrode layer 42 with respect to the vibrator part 23. The step of forming a conductor layer for forming the film is also performed at the same time.

  In the first electrode layer forming step, a titanium thin film layer is formed by sputtering titanium over the entire surface of the silicon oxide film layer 30B of the vibrator constituting portion 35, and platinum is sputtered on the titanium thin film layer. A platinum layer is formed to form a first electrode layer 40 having a two-layer structure. In the titanium thin film layer forming step, a titanium thin film layer having a thickness of about 50 nm is formed on the silicon oxide film layer 30B under sputtering conditions of a gas pressure of 0.5 Pa and an RF (high frequency) power of 1 kW. In the platinum layer forming step, a platinum thin film layer having a thickness of about 200 nm is formed on the titanium thin film layer under sputtering conditions of a gas pressure of 0.5 Pa and an RF power of 0.5 kW.

  As for the 1st electrode layer 40, while a titanium thin film layer has the effect | action which improves the adhesiveness with the silicon oxide film layer 30B, a platinum layer acts as a favorable electrode. In the first electrode layer forming step, the electrode layer constituting the first lead 31A and the first terminal portion 25A is formed by extending from the diaphragm portion 38 to the formation region of the base portion 22 simultaneously with the formation of the first electrode layer 40 described above. Form.

In the piezoelectric film layer forming step, a piezoelectric film layer 37 having a predetermined thickness is formed by sputtering, for example, lead zirconate titanate (PZT) over the entire surface of the first electrode layer 40 described above. The piezoelectric film layer forming step is performed by using a Pb _{(1 + x)} (Zr _0.53 Ti _0.47 ) O _3-y oxide as a target and a sputtering condition with a gas pressure of 0.7 Pa and an RF power of 0.5 kW. A piezoelectric film layer 41 made of a PZT layer having a thickness of about 1 μm is formed on the electrode layer 40 as a thin film. In the piezoelectric film layer forming step, a crystallization heat treatment is performed by baking the piezoelectric film layer 41 with an electric furnace. For example, the baking process is performed in an oxygen atmosphere at 700 ° C. for 10 minutes. The piezoelectric film layer 41 is formed so as to cover a part of the electrode layer formed in the formation region of the base portion 22 extended from the first electrode layer 40 described above.

  In the second electrode layer forming step, the second electrode layer 42 is formed by laminating platinum over the entire surface of the piezoelectric film layer 41 to form a platinum layer by sputtering platinum. In the second electrode layer forming step, a platinum thin film layer having a thickness of about 200 nm is formed on the piezoelectric film layer 41 under sputtering conditions of a gas pressure of 0.5 Pa and an RF power of 0.5 kW.

  As shown in FIGS. 17 and 18, the vibration element manufacturing process is driven in a predetermined shape as shown in FIGS. 17 and 18 by the second electrode layer patterning process in which the second electrode layer 42 formed in the uppermost layer through the above-described processes is subjected to the patterning process. An electrode layer 29 and a pair of detection electrodes 30R and 30L are formed. The drive electrode layer 29 is an electrode to which a predetermined drive voltage for driving the vibrator unit 23 is applied as described above, and the longitudinal direction with a predetermined width in the center region in the width direction of the vibrator unit 23. Is formed over almost the entire area. The detection electrode 30 is an electrode for detecting the Coriolis force generated in the vibrator unit 23 and is formed on the both sides of the drive electrode layer 29 so as to be insulated from each other over almost the entire length direction in parallel. The

  In the second electrode layer patterning step, the second electrode layer 42 is subjected to a photolithography process to form the drive electrode layer 29 and the detection electrode 30 on the piezoelectric film layer 37 as shown in FIG. In the second electrode layer patterning step, a resist layer is formed on the second electrode layer 42, and the resist layer is washed after removing a corresponding portion between the drive electrode layer 29 and the detection electrode 30 by, for example, an ion etching method. Through the process, the drive electrode layer 29 and the detection electrode 30 are patterned. The second electrode layer patterning step is not limited to this step, and the drive electrode layer 2 and the detection electrode 30 may be formed using an appropriate conductive layer forming step employed in the semiconductor process. Of course.

  In the second electrode layer patterning step, the drive electrode layer 29 and the detection electrode 30 are formed so as to be the same at the root portion 43 as the root of the vibrator portion 23 as well as the tip portion as shown in FIG. The In the second electrode layer patterning step, lead connection portions 29-1, 30R-1, and 30L-1 that are widened at the base end portions of the drive electrode layer 29 and the detection electrode 30 that are matched at the root portion 43, respectively. Are integrally formed with a pattern.

  In the second electrode layer patterning step, for example, the first detection electrode 30R and the second detection electrode 30L each having a width dimension t14 of 10 μm sandwiching the drive electrode layer 29 having a length dimension t12 of 2 mm and a width dimension t13 of 50 μm. Are formed with an interval dimension t15 of 5 μm. In the second electrode layer patterning step, lead connection portions 29-1, 30R-1, and 30L-1 having a length dimension t16 of 50 μm and a width dimension t17 of 50 μm, respectively, are pattern-formed. In the second electrode layer patterning step, the drive electrode layer 29 and the detection electrode 30 are not limited to the above-described dimension values, and can be formed on the second main surface of the vibrator portion 23. It is formed as appropriate.

  In the vibration element manufacturing process, the piezoelectric thin film layer 28 is formed by performing a piezoelectric film layer patterning process on the piezoelectric film layer 41 while leaving a portion having a larger area than the drive electrode layer 29 and the detection electrode 30 described above. The piezoelectric thin film layer 28 is slightly smaller than the width of the vibrator portion 23 and is formed from the proximal end portion to the vicinity of the distal end of the distal end portion.

  In the piezoelectric film layer patterning process, a photolithography process is performed on the piezoelectric film layer 41 to form a resist layer at a corresponding portion of the piezoelectric thin film layer 28, and the piezoelectric film layer 41 at an unnecessary portion is made of, for example, a hydrofluoric acid solution. After removal by a wet etching method or the like, the piezoelectric thin film layer 28 shown in FIGS. 19 and 20 is formed through a process such as cleaning the resist layer. In the piezoelectric film layer patterning step, the piezoelectric film layer 41 is etched by a wet etching method. However, the present invention is not limited to such a process, and for example, an ion etching method or a reactive ion etching method (RIE). Of course, the piezoelectric thin film layer 28 may be formed by applying an appropriate method such as (Reactive Ion Etching).

  In the piezoelectric film layer patterning step, the base end portion of the piezoelectric thin film layer 28 is made to be the same as the drive electrode layer 29 and the detection electrode 30 at the root portion 43 which is the root of the vibrator portion 23 as shown in FIG. It is formed. In the piezoelectric film layer patterning step, the terminal receiving portion 28-1 has a larger area than the lead connection portions 29-1, 30R-1, and 30L-1 of the drive electrode layer 29 and the detection electrode 30 from the base end portion. Patterned together.

  In the piezoelectric film layer patterning step, the piezoelectric thin film layer 28 having a length dimension t18 of 2.2 mm and a width dimension t19 of 90 μm is patterned. In the piezoelectric film layer patterning step, the terminal receiving portion 28-1 is patterned with a width of 5 μm around the lead connecting portions 29-1, 30R-1, and 30L-1. In the piezoelectric film layer patterning step, the piezoelectric thin film layer 28 is not limited to the above-described dimension value, and has a larger area than the drive electrode layer 29 and the detection electrode 30, and the second main main portion of the vibrator unit 23. It is suitably formed as long as it can be formed on the surface.

  In the vibration element manufacturing process, the same patterning process as that of the second electrode layer patterning process described above is performed on the first electrode layer 40 from which the piezoelectric film layer 41 has been removed by the first electrode layer patterning process. The reference electrode layer 27 is patterned as shown in FIG. In the first electrode layer patterning step, a resist layer is formed on the first electrode layer 40, the corresponding portion of the reference electrode layer 27 is removed by, for example, an ion etching method, and then the resist layer is washed. The electrode layer 27 is patterned. The first electrode layer patterning step is not limited to this step, and it is needless to say that the reference electrode layer 27 may be formed using an appropriate conductive layer forming step employed in the semiconductor process.

  In the first electrode layer patterning step, the reference electrode layer 27 is formed on the second main surface of the vibrator portion 23 and has a width slightly smaller than the width and larger than the piezoelectric thin film layer 28. In the first electrode layer patterning step, the drive electrode layer 29, the detection electrode 30, the piezoelectric thin film layer 28, and the base end portion of the reference electrode layer 27 are located at the root portion 43 that is the root of the vibrator portion 23 as shown in FIG. They are formed to be the same. In the first electrode layer patterning step, the first lead 31A and the first terminal portion 25A are pattern-formed on the portion where the base portion 22 is formed by being pulled out integrally from the base end portion. In the first electrode layer patterning step, the length dimension t20 is 2.3 mm, the width dimension t21 is 94 μm, and the reference electrode layer 27 is formed around the piezoelectric thin film layer 28 with a width dimension of 5 μm. Note that the first electrode layer patterning step is not limited to the above-described dimension value, and is appropriately formed as long as the reference electrode layer 27 can be formed on the second main surface of the vibrator portion 23. .

  The vibration element 20 includes the drive electrode layer 29 formed in the formation portion of the base portion 22 through the above-described steps, the lead connection portions 29-1, 30R-1, and 30L-1 of the detection electrode 30, and the terminal portions 25B to 25D. The leads 31B to 31D are connected to each other. In the vibration element manufacturing process, the planarization layer 24 shown in FIGS. 23 and 24 is formed so that the leads 31B to 31D are smoothly connected to the opposing lead connection portions 29-1, 30R-1, and 30L-1.

  In the vibration element 20, the leads 31 </ b> B to 31 </ b> D that connect the lead connection portions 29-1, 30 </ b> R- 1 and 30 </ b> L- 1 to the terminal portions 25 </ b> B to 25 </ b> D are the terminal receiving portions 28-1 and the reference electrode layers of the piezoelectric thin film layer 28. The portion where the base portion 22 is formed is routed through the end portion of 27. In the vibration element 20, as described above, the piezoelectric thin film layer 28 performs patterning by performing wet etching on the piezoelectric film layer 41, so that the end portion of the etching portion is on the second main surface 21-2 side of the silicon substrate 21. It is a reverse taper or a vertical step. In the vibration element 20, when the leads 31 </ b> B to 31 </ b> D are directly formed at the formation portion of the base portion 22, disconnection is caused at the stepped portion. In the vibration element 20, the first lead 31 </ b> A of the reference electrode layer 27 is routed around the base 22 so as to be exposed from the terminal receiving portion 28-1 of the piezoelectric thin film layer 28. It is also necessary to maintain insulation between the one lead 31A and the leads 31B to 31D.

  In the planarization layer forming step, the resist layer formed on the formation portion of the base portion 22 is subjected to photolithography processing to cover the lead connection portions 29-1, 30R-1, 30L-1 and the first lead 31A. The pattern is formed. In the planarization layer forming step, the patterned resist layer is heated and cured at about 280 ° C. to 300 ° C. to form the planarization layer 24. In the planarization layer forming step, the planarization layer 24 having a width dimension t24 of 200 μm, a length dimension t25 of 50 μm, and a thickness dimension of 2 μm is formed. Note that the planarization layer forming step is not limited to this step, and the planarization layer 24 is formed using an appropriate resist layer forming step performed in a semiconductor process or the like or an appropriate insulating material. May be.

  In the vibration element manufacturing process, the wiring layer forming process for forming the second terminal portion 25B to the fourth terminal portion 25D and the second lead 31B to the fourth lead 31D described above is performed on the formation portion of the base portion 22. In the wiring layer forming step, a photosensitive photoresist layer is formed over the entire surface of the base 22 forming portion, and the photoresist layer is subjected to a photolithography process to form the second terminal portion 25B to the fourth terminal portion. An opening pattern corresponding to 25D and the second lead 31B to the fourth lead 31D is formed, and a conductor layer is formed in each opening by sputtering to form a wiring layer. In the wiring layer forming step, after a predetermined conductor portion is formed, the photoresist layer is removed and the second terminal portion 25B to the fourth terminal portion 25D and the second lead 31B to the fourth lead 31D shown in FIGS. The pattern is formed.

  In the wiring layer forming step, after forming a titanium layer for improving the adhesion to the silicon oxide film 33B, a low-cost copper layer having a low electrical resistance is formed on the titanium layer. In the wiring layer forming step, the titanium layer is formed with a thickness of 20 nm, and the copper layer is formed with a thickness of 300 nm. The wiring layer forming step is not limited to such a step, and the wiring layer may be formed by various wiring pattern forming techniques widely used in a semiconductor process, for example.

  In the vibration element manufacturing process, an outer shape groove forming process that penetrates the diaphragm portion 38 and constitutes the outer peripheral portion of the vibrator portion 23 is performed. The groove forming step is a diagram in which the root portion 43 on the one side of the vibrator portion 23 of the silicon substrate 21 on which the above-described electrode layers are stacked is started and the root portion 43 on the other side is terminated so as to surround the vibrator portion 23. A substantially U-shaped outer groove 39 shown in FIG. 27 and FIG. 28 is formed. The outer shape groove 39 is formed with a width of 200 μm as described above.

  Specifically, the outer shape groove forming step includes a first etching step for removing the silicon oxide film 33B in a U-shape and a second etching step for forming a through groove in the exposed silicon substrate 21. In the first etching step, a photosensitive photoresist layer is formed over the entire surface of the silicon oxide film 33B, and a photolithographic process is performed on the photoresist layer to form a U-shaped opening pattern. In the first etching step, the silicon oxide film 33B exposed in the opening pattern is removed by ion etching. In the first etching step, the silicon oxide film 33B can be removed in a U shape by, for example, wet etching, but ion etching is preferably performed in consideration of generation of a dimensional error due to side etching. .

In the outer shape groove forming step, the second etching step is performed using the remaining silicon oxide film 33B as a protective film. In the second etching step, for example, reactive ion etching is performed on the silicon substrate 21 so that the outer peripheral portion of the vibrator portion 23 is configured by a highly accurate vertical surface. In the second etching process, an etching apparatus including an inductively coupled plasma (ICP) that generates high-density plasma is used, and an etching process for introducing SF ₆ gas and a C ₄ F ₈ gas are used. Formed on the silicon substrate 2 is an external groove 39 having a vertical inner wall at a speed of about 10 μm per minute by a Bosch (Bosch) process that repeats a protective film forming step for protecting the outer peripheral wall at the introduced and etched location. To do.

  In the vibration element manufacturing process, a cutting process for separating each vibration element 20 from the silicon substrate 21 is performed. In the vibration element manufacturing process, each vibration element 20 is cut by cutting the base 22 with a diamond cutter or the like, for example. About a cutting process, after forming a cutting groove with a diamond cutter, the silicon substrate 21 is folded and divided. In the cutting step, cutting may be performed using a surface orientation of the silicon substrate 21 by a grindstone or grinding.

  In the vibration element manufacturing process, since the vibration element 20 is surface-mounted on the support substrate 2 as described above, the gold bumps 26 are formed on the respective terminal portions 25. In the gold bump forming process, a plating resist layer having a predetermined opening is formed on the terminal portion 25, and after the gold plating layer is grown to a predetermined height in each opening by gold plating, the plating resist layer is removed. The gold bumps 26 are formed by a lift-off method or the like.

  In the gold bump forming step, the thickness (height) of the gold bump 26 formed by the plating process is limited, and the gold bump 26 having a desired height may not be formed. In the gold bump forming process, when a desired gold bump 26 cannot be obtained by a single plating process, a so-called stepped gold bump 26 is formed by performing a twice plating process using the first gold plating layer as an electrode. You may make it form. In the gold bump forming process, so-called dummy bumps are also formed on the base 22 as necessary.

  In the vibration element manufacturing process, not only bump formation by the gold plating method described above but also bump formation by an appropriate bump formation technique implemented in a semiconductor process, for example, vapor deposition method, transfer method, stud bump or the like. Of course, it is also good. Further, in the vibration element manufacturing process, in order to improve the adhesion between the gold bump 26 and each terminal portion 25, a so-called bump base metal layer is formed on each terminal portion 25 although the details are omitted.

  The vibration element 20 manufactured through the above steps is mounted on the main surface 2-1 of the support substrate 2 by a surface mounting method with the second main surface 21-2 side of the silicon substrate 21 as a mounting surface. In the vibration element 20, the gold bumps 26 provided on the terminal portions 25 are aligned with the opposing lands 4 on the support substrate 2 side. As described above, the vibration element 20 is mounted by reading the alignment mark 32 and positioning the position and orientation with high accuracy by a mounting machine. The vibration element 20 is mounted on the main surface 2-1 of the support substrate 2 by welding the gold bumps 26 to which the ultrasonic waves are applied while pressed against the support substrate 2 to the opposing lands 4. A cover member 15 is attached to the support substrate 2 after mounting the IC circuit element 7 and the electronic component 8 on the main surface 2-1 to complete the vibration gyro sensor 1.

  In the vibration type gyro sensor 1, when the vibration element 20 is applied with an alternating voltage of a predetermined frequency from the drive detection circuit unit 50 to the drive electrode layer 29, the vibrator unit 23 has a specific frequency. Vibrate. In the vibration type gyro sensor 1, the vibrator unit 23 of the vibration element 20 resonates at the longitudinal resonance frequency in the thickness direction and at the longitudinal resonance frequency, and also resonates at the lateral resonance frequency in the width direction. The vibration type gyro sensor 1 has higher sensitivity characteristics as the detuning degree, which is the difference between the longitudinal resonance frequency and the transverse resonance frequency, of the vibration element 20 is smaller. As described above, the vibration type gyro sensor 1 is subjected to the crystal anisotropic etching process and the reactive ion etching process to accurately form the outer peripheral part of the vibrator part 23 so as to achieve a high degree of detuning.

  The vibration element 20 has a great influence on the longitudinal resonance frequency characteristics due to the accuracy of the length dimension t5 of the vibrator portion 23. As described above, in the vibration element 20, the root portion 43 that defines the length dimension t5 of the vibrator portion 23 is formed by performing crystal anisotropic etching treatment on the (100) plane of the diaphragm portion 38 and 55 °. When a “deviation” occurs between the (111) plane that is the inclined surface and the boundary line that is a flat surface, the degree of detuning increases in accordance with this “deviation” amount.

  That is, in the vibration element 20, the amount of such “deviation” is caused by the positional deviation between the resist film pattern formed on the silicon oxide film 33B during the crystal anisotropic etching process and the resist film pattern during the reactive ion etching process. It becomes. Accordingly, the vibration element 20 may be positioned by a double-side aligner that can observe the front and back main surfaces 21-1 and 21-2 of the silicon substrate 21 at the same time in the process. In addition, the vibration element 20 may be appropriately positioned by an alignment device that forms an appropriate positioning pattern or mark on the main surface of the silicon substrate 21 and regulates the position of the other main surface based on these patterns. Good. The vibration element 20 can be applied to the positioning process on the support substrate 2 in correspondence with the positioning.

  In the vibration element 20, the longitudinal resonance frequency and the transverse resonance frequency substantially coincide with each other if the above-described “deviation” amount is in a range smaller than about 30 μm. Therefore, the vibration element 20 can suppress a decrease in the detuning characteristic due to a substantial “deviation” amount by performing a slightly accurate etching process, and eliminates the need for the above-described alignment apparatus. Manufactured.

  By the way, in a general semiconductor process, an N-type or P-type silicon substrate subjected to doping treatment such as Bo or Ph is used. For this reason, a general silicon substrate has a volume resistivity of several tens of Ω · cm, has a certain degree of conductivity, and has a ground function, a lower electrode function when forming a thin film, and the like. On the other hand, as described above, the vibration element 20 is a pure silicon single crystal silicon substrate that is not subjected to doping treatment or a single crystal silicon substrate having a volume resistivity of 100 Ω · cm or more. The silicon substrate 21 has an extremely high resistance value characteristic, and thus has a low conductive characteristic.

  As described above, the silicon substrate 21 has the silicon oxide films 33A and 33B formed on the front and back main surfaces 21-1 and 21-2, and the silicon oxide film 33 functions as a protective film when each etching process is performed. In the vibration element manufacturing process, the silicon oxide film 33 is removed to form a rectangular recess 37 in the silicon substrate 21 in order to form a diaphragm portion 38 having a predetermined thickness. The silicon substrate 21 may be damaged by the silicon oxide film 33 when foreign matter or the like is mixed in the photoresist material applied during the etching process or the like. In the silicon substrate 21, there may be “soot” generated in the silicon oxide film 33 that is difficult to detect by appearance inspection, fine scratches, scratches in the process, or the like.

  In the vibration element manufacturing process, when a general silicon substrate is used, as described above, the first electrode layer 40 formed as a thin film on the silicon oxide film 33B is electrically connected to the silicon substrate 21 through the scratches described above. At the same time, the second electrode layer 42 becomes conductive through a silicon substrate having better conductivity. In the vibration element manufacturing process, when a general conductive silicon substrate is used, a short circuit defect with a yield rate of about 20% has occurred. In the vibration element manufacturing process, when a general silicon substrate is used, a silicon oxide film having a sufficient thickness is formed, and high-precision inspection and sufficient process management are required.

  On the other hand, in the vibration element manufacturing process, the short-circuit failure rate is reduced to about 4% by manufacturing the vibration element 20 using the low-conductivity silicon substrate 21 as described above. . Further, in the vibration element manufacturing process, it is possible to efficiently perform temperature management and gas management in each process, and it is also possible to form each electrode layer and piezoelectric thin film layer with high accuracy. Significant efficiency improvement will be achieved.

  The vibration type gyro sensor 1 includes the vibration element 20 manufactured using the low-conductivity silicon substrate 21 as a base material, so that a stable operation can be performed against disturbances such as external light and heat load. . The vibration-type gyro sensor 1 has a reduced capacitance change of the piezoelectric thin film layer 28 due to external light and an offset as compared with a vibration-type gyro sensor including a vibration element formed of a general N-type or P-type silicon substrate. A high-sensitivity and stable camera shake detection operation with a small change in voltage value is performed.

  In the vibration element manufacturing process, as described above, a large number of vibration elements 20 formed by integrally forming the vibrator portion 23 on the base portion 22 are collectively manufactured on the silicon substrate 21 and separated from each other. In the vibration element manufacturing process, the first vibration element 20 </ b> X having the same shape and the first vibration element 20 </ b> X provided in the vibration type gyro sensor 1 mounted on the main surface of the support substrate 2 so as to be positioned on two axes and obtaining a detection signal of two axes are provided. The two vibration element 20Y is manufactured.

  The basic configuration of the vibration element 20 manufactured through the above steps will be described below. As described above, the vibrating element 20 has the base portion 22 having a thickness dimension larger than 1.5 times the thickness dimension t4 of the vibrator section 23. In the vibration element 20, the resonance frequency (KHz) characteristic changes as shown in FIG. 29 by changing the thickness dimension t <b> 1 of the base portion 22. As is clear from the figure, the vibration element 20 is formed such that the thickness dimension t1 of the base portion 22 is larger than 1.5 times the thickness dimension t4 of the vibrator portion 23, so that the resonance frequency is kept constant. As the thickness dimension t1 of the base portion 22 is smaller than 1.5 times the thickness dimension t4 of the vibrator portion 23, the vibration element 20 is shifted in resonance frequency.

  The vibration element 20 gradually decreases in mechanical rigidity as the base portion 22 is thinned, and the vibration operation of the vibrator portion 23 causes the base portion 22 to vibrate and causes a shift in the resonance frequency. . In the vibration element 20, the base 22 is formed under the above-described conditions, so that the base 22 is fixed to the support substrate 2 while being thinned and maintaining sufficient mechanical rigidity. In the vibration element 20, the occurrence of a shift in the resonance frequency due to the vibration operation of the base portion 22 is suppressed, and the vibration portion 23 performs the vibration operation in a stable state, so that highly accurate hand shake and the like can be detected. .

  As shown in FIG. 30A, the vibration element 20 has a base portion 22 having a width dimension larger than twice the width dimension t6 of the vibrator section 23 and a longitudinal axis C of the vibrator section 23. On the other hand, the center of gravity G-1 is located in the region within the range of [± 2 × t6]. The vibration element 20 is fixed on the main surface 2-1 of the support substrate 2 through the gold bumps 25 </ b> A to 25 </ b> D provided with the base 22 at the four corners, and the vibrator 23 is vibrated in the thickness direction by being supported by the base 22. Operate.

  On the other hand, in the vibration element 60 shown in FIG. 30B, for example, the vibrator portion 23 is formed so as to protrude integrally from the outer peripheral portion with a position shifted to one side in the longitudinal direction with respect to a base portion 61 formed in a horizontally long rectangle. ing. The vibration element 60 is provided with gold bumps 62A to 62D located at the four corners of the base 61, and the base 61 is fixed on the main surface 2-1 of the support substrate 2 through the gold bumps 62A to 62D. The The vibration element 60 is in a state in which the center of gravity G-2 of the base portion 61 is shifted by Δx1 to the side with respect to the central axis C in the longitudinal direction of the vibrator portion 23 due to the structure described above.

  For the vibration element 20 and the vibration element 60 having the vibration element part 23 with the width t6 of the vibration element part 23 being 100 μm, the gravity centers G-1 and G-2 of the base portions 22 and 61 with respect to the central axis C of the vibration element part 23 With respect to the influence of deviation, the state of output balance from the left and right detection electrodes 30R, 30L was measured, and the result is shown in FIG. In the vibration element 20 in which the center of gravity G-1 of the base portion 22 is formed within a range of [± 2 × t6] with respect to the central axis C of the vibration element portion 23, as is apparent from FIG. There is almost no difference and a characteristic that is maintained in a balanced state is obtained. Therefore, the vibration element 20 performs a vibration operation in a state where the vibrator unit 23 is stable, and the detection signal based on the displacement of the vibrator unit 23 due to the Coriolis force generated by hand shake or the like becomes a stable level without losing the left-right balance. Thus, high-precision camera shake and the like are detected.

  On the other hand, the vibration element 60 formed so that the center of gravity G-2 of the base 61 is displaced from the range of [± 2 × t6] with respect to the central axis C of the vibration element unit 23 is detected on the left and right sides as the displacement amount increases. A characteristic is obtained in which the signal difference gradually increases and the balance is lost. As is apparent from this result, the vibration element 60 performs a vibration operation in a state in which the vibrator unit 23 is inclined obliquely with a mode of vibration operation shifted from an ideal vertical direction. Therefore, the reliability of the vibration element 60 is impaired by the unstable vibration operation of the vibrator unit 23.

  The vibration element 20 is fixed on the main surface 2-1 of the support substrate 2 through the gold bumps 25 </ b> A to 25 </ b> D provided at the four corners of the base portion 22 as described above, and the vibrator portion 23 is supported by the base portion 22. Vibrates in the thickness direction. As shown in FIG. 31A, the vibration element 20 has the center of gravity BG-1 of the four gold bumps 25A to 25D such that the width dimension of the vibrator part 23 with respect to the central axis C in the longitudinal direction of the vibrator part 23. It is provided in the base portion 22 so as to be located in a region within the range of t6.

  On the other hand, the vibration element 70 shown in FIG. 31B is also fixed on the main surface 2-1 of the support substrate 2 via the gold bumps 72 </ b> A to 72 </ b> D provided on the base 71, and is supported by the base 71 to vibrate. The child portion 23 vibrates in the thickness direction. In the vibration element 70, the gold bumps 72 </ b> A to 72 </ b> D are provided at appropriate positions with respect to the base 71, whereby the center of gravity BG-2 of the four gold bumps 72 </ b> A to 72 </ b> D is the center in the longitudinal direction of the vibrator unit 23. It is in a state of being shifted by Δx2 from the region within the range of the width dimension t6 of the vibrator portion 23 with respect to the axis C.

  For the vibration element 20 and the vibration element 70 having the vibration element part 23 with the width t6 of the vibration element part 23 being 100 μm, the centers of gravity BG-1 and BG− of the respective gold bumps 25 and 72 with respect to the central axis C of the vibration element part 23. Regarding the influence of the deviation of 2, the state of the output balance from the left and right detection electrodes 30R, 30L was measured, and the result is shown in FIG. As described above, in the vibration element 20 in which each gold bump 25 is provided in the base portion 22 with the center of gravity BG-1 positioned within the range of the width dimension t6 with respect to the central axis C of the vibration element portion 23, it is apparent from FIG. Thus, there is almost no difference between the left and right detection signals, and a characteristic that is maintained in a balanced state is obtained. Therefore, the vibration element 20 performs a vibration operation in a state where the vibrator unit 23 is stable, and the detection signal based on the displacement of the vibrator unit 23 due to the Coriolis force generated by hand shake or the like becomes a stable level without losing the left-right balance. Thus, high-precision camera shake and the like are detected.

  On the other hand, each of the gold bumps 72 has the center of gravity BG-2 shifted from the center axis C of the vibration element portion 23 from the range of the width dimension t6. The difference between the detected signals gradually increases and the balance is lost. As is apparent from this result, the vibration element 70 performs a vibration operation in a state where the vibrator unit 23 is inclined obliquely with a mode of vibration operation shifted from an ideal vertical direction. Therefore, the reliability of the vibration element 70 is impaired by the unstable vibration operation of the vibrator unit 23.

  As shown in FIG. 33A, the vibration element 20 extends from the base portion 43 of the vibrator portion 23 protruding from the base portion 22 to the outer region of the region having a radius r that is twice the width dimension t6 of the vibrator portion 23. The gold bumps 25 </ b> A to 25 </ b> D are provided, and the base 22 is fixed on the main surface 2-1 of the support substrate 2 through the gold bumps 25. In the vibration element 20, as described above, each gold bump 25 functions to absorb the vibration of the vibrator portion 23, so that the output characteristics of the detection signal change depending on the interval from the root portion 43 of the vibrator portion 23. .

  FIG. 33B is a characteristic diagram of a change in output of the detection signal accompanying a change in the distance between the gold bumps 25 with respect to the root portion 43 of the transducer unit 23. In the vibration element 20, as the gold bump 25 approaches the root portion 43 of the vibrator portion 23, the above-described vibration absorbing action by the gold bump 25 increases, and the Q value gradually decreases. In the vibration element 20, as is clear from the figure, the gold bumps 25A and 25D provided on the base portion 43 side are outside regions where the radius r is twice the width dimension t6 of the vibrator portion 23 from the root portion 43. The detection signal of a stable level is obtained by providing in. That is, the vibration element 20 reduces the influence of the gold bumps 25 on the vibration operation of the vibrator unit 23 with the above-described configuration, so that the reduction of the Q value is suppressed and high-precision camera shake is detected. Become.

  As shown in FIG. 34A, the vibration element 20 includes four gold bumps 25A provided in a region within a range twice the thickness dimension t1 of the base portion 22 from the root portion 43 of the vibrator portion 23. The base 22 is fixed on the main surface 2-1 of the support substrate 2 through ˜25D. In the vibration element 20, for example, the gold bumps 25A and 25D on the side of the root portion 43 of the vibrator portion 23 have a horizontal distance s of 1.5 times the thickness dimension t1, that is, 450 μm or more, with respect to the base portion 22 having a thickness dimension t1 of 300 μm. It is formed with a close interval. In the vibration element 20, as the gold bump 25 moves away from the root portion 43 of the vibrator portion 23, the interval between the non-bonded portions between the root portion 43 of the base portion 22 and the gold bump 25 increases. With the vibration operation 23, vibration is generated in the base portion 22.

  In the vibration element 20, the output characteristic of the detection signal varies depending on the size of the interval s between the fixed position of the base portion 22 and the root portion 43 of the vibrator portion 23. FIG. 34B is a characteristic diagram of an output change of the detection signal accompanying a change in the horizontal distance s of the gold bump 25 with respect to the root part 43 of the transducer unit 23. In the vibration element 20, as apparent from the figure, when the position of the gold bump 25 is 450 μm or more from the root part 43, the deviation of the resonance frequency gradually increases. In the vibration element 20, as described above, the gold bump 25 is provided in the region within the range twice the thickness dimension t <b> 1 from the root portion 43 with respect to the base portion 22, whereby the resonance frequency due to the vibration of the base portion 22 is increased. Occurrence of deviation is suppressed, and a vibration operation is performed in a state in which the vibrator unit 23 is stable, so that a highly accurate hand shake or the like is detected.

It is a principal part disassembled perspective view which removes a cover member and shows the vibration type gyro sensor shown as embodiment. It is principal part sectional drawing of a vibration type gyro sensor. It is a principal part bottom view of a vibration element. It is a circuit block diagram of a vibration type gyro sensor. It is a figure explaining the dimension value of each part of a vibration element. It is a figure explaining the dimension value of each part of a vibrator part. It is a top view of the silicon substrate used for the manufacturing process of a vibration element. It is a side view of a silicon substrate. It is a top view of the silicon substrate which patterned the vibration element formation part in the photoresist layer. It is sectional drawing of the silicon substrate. It is a top view of the silicon substrate which patterned the vibration element formation part in the silicon oxide film layer. It is sectional drawing of the silicon substrate. It is a top view of the silicon substrate in which the rectangular recessed part which comprises the diaphragm part which prescribes | regulates the thickness of a vibrator | oscillator part was formed. It is sectional drawing of the silicon substrate. It is principal part sectional drawing explaining the structure of a diaphragm part. It is principal part sectional drawing of the state which laminated | stacked and formed the 1st electrode layer, the piezoelectric film layer, and the 2nd electrode layer in the diaphragm part. It is a principal part top view of the state which patterned the drive electrode layer and the detection electrode in the 2nd electrode layer. It is the principal part sectional drawing. It is a principal part top view of the state which patterned the piezoelectric thin film layer on the piezoelectric film layer. It is the principal part sectional drawing. It is a principal part top view of the state which patterned the reference electrode layer in the 1st electrode layer. It is the principal part sectional drawing. It is principal part sectional drawing of the length direction of the state which formed the external shape groove | channel which forms the external shape of a vibrator | oscillator part. It is principal part sectional drawing of the same width direction. It is a principal part top view in the state where the wiring layer was formed in the base formation part. It is the principal part sectional drawing. It is principal part sectional drawing of the state which formed the external shape groove | channel which comprises the external shape of a vibrator | oscillator part. It is the principal part longitudinal cross-sectional view. FIG. 6 is a characteristic diagram showing a shift in resonance frequency depending on a thickness dimension of a base portion of a vibration element. FIG. 3A is a diagram in which a deviation between a center axis of a vibrator portion and a center of gravity of a base portion in a vibration element is analyzed. FIG. 3A is a bottom view of a main part of the vibration element of the embodiment, and FIG. The bottom view of the principal part of the element, FIG. 5C is a characteristic diagram of the deviation of the center of gravity and the deviation of the detection signal. It is the figure which analyzed the shift | offset | difference of the center axis line of the vibrator | oscillator part in a vibration element, and the gravity center of a gold bump, The figure (A) is a principal part bottom view of the vibration element of embodiment, and the figure (B) has a gap. It is a principal part bottom view of a vibration element. FIG. 10 is a characteristic diagram of a deviation of a center axis of a vibrator part, a center of gravity of a gold bump, and a deviation of a detection signal in a vibration element. It is the figure which analyzed the position of the gold bump from the root part of a vibrator part in a vibration element, the figure (A) is a principal part bottom view of a vibration element of an embodiment, and the figure (B) is a vibrator part. It is a characteristic view of the position of the gold bump from the root part and the detection signal level. It is the figure which analyzed the horizontal position of the gold bump from the root part of a vibrator part in a vibration element, the figure (A) is a principal part bottom view of a vibration element of an embodiment, and the figure (B) is a vibrator part. FIG. 6 is a characteristic diagram of a position of a gold bump from a root part of the wire and a detection signal level.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibration type gyro sensor, 2 support substrate, 3 component mounting space part, 4 land, 5 wiring pattern, 6 component mounting area, 7 IC circuit element, 8 electronic component, 9 light shielding step part, 10 cover fixing part, 11 space | interval structure Concave part, 15 cover member, 16 main surface part, 17 outer peripheral wall part, 18 outer peripheral flange part, 19 light shielding layer, 20 vibration element, 21 silicon substrate, 22 base part, 23 vibrator part, 24 flattening layer, 25 terminal part, 26 Gold bump, 27 Reference electrode layer, 28 Piezoelectric thin film layer, 29 Drive electrode layer, 30 Detection electrode, 31 Lead, 32 Alignment mark, 33 Silicon oxide film, 38 Diaphragm part, 39 Outline groove, 40 First electrode layer, 41 Piezoelectric film layer, 42 Second electrode layer, 50 Drive detection circuit section, 51 Impedance conversion circuit, 52 Addition circuit, 53 Oscillation circuit, 54 Differential amplification circuit, 55 Synchronization Detection circuit, 56 DC amplification circuit, 57 Reference potential

Claims (5)

A support substrate on which a circuit pattern is mounted and a wiring pattern having a plurality of lands is formed;
A base portion provided with a plurality of connection terminal portions and fixed to the support substrate, and protruding in a cantilever shape from the outer peripheral portion of the base portion, and in the longitudinal direction with the connection terminal portions as base ends. And a vibration element comprising a vibrator portion in which a first electrode layer, a second electrode layer, and a detection electrode are laminated via a piezoelectric thin film layer,
The vibration element has a width larger than twice the width dimension (t6) of the vibrator portion and a range of [± 2 × t6] with respect to the central axis in the longitudinal direction of the vibrator portion. A vibration type gyro sensor characterized in that the center of gravity is positioned in the inner region.   2. The vibration gyro sensor according to claim 1, wherein the vibration element has the base portion having a thickness larger than 1.5 times a thickness dimension (t4) of the vibrator portion. The vibration element is mounted at a predetermined interval on the support substrate by welding metal bumps provided at least on the connection terminal portions to the respective lands facing each other.
2. The metal bumps according to claim 1, wherein each of the metal bumps is provided in a region within a range of a width dimension (t 6) with respect to a central axis in a longitudinal direction of the vibrator portion, with the entire center of gravity positioned. Vibration gyro sensor. The vibration element is mounted at a predetermined interval on the support substrate by welding metal bumps provided at least on the connection terminal portions to the respective lands facing each other.
2. The vibration gyro sensor according to claim 1, wherein each of the metal bumps is provided in an outer region of a radius [2 × t6] from a base portion of the vibrator portion protruding from the base portion. The vibration element is mounted at a predetermined interval on the support substrate by welding metal bumps provided at least on the connection terminal portions to the respective lands facing each other.
At least one of the metal bumps is provided in a region within a range of [2 × t1] from the base portion of the vibrator portion protruding from the base portion having a thickness dimension (t1). The vibration type gyro sensor according to claim 1.

Images