JP2010002348A - Physical quantity sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a physical quantity sensor device for mounting the face of a circuit substrate by completing a mounting process in one time. <P>SOLUTION: The physical quantity sensor device includes: a mounting substrate 2 erected in a height direction (Z direction) on a circuit substrate 6; and a gyro sensor element 3 mounted on a vertical face 8a of the mounting substrate 2 by being seen from the surface of the circuit substrate 6. The bottom face 36 of the mounting substrate 2 is a mounting face to the circuit substrate 6 exposing an electrode 35. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention particularly relates to a physical quantity sensor device for mounting a physical quantity sensor element in a standing state.

  For example, in a gyro sensor device equipped with a tuning fork type vibrator, in order to detect the angular velocity Ω around the axis in the Z-axis direction (height direction), the tuning-fork type vibrator is mounted in a standing state in the Z-axis direction. There must be.

Patent Document 1 below discloses an invention related to an angular velocity sensor.
The angular velocity sensor shown in Patent Document 1 is configured such that the vibrator 21 is stowed in a case 30 and the case 30 having the vibrator 21 is housed in a housing portion 43.

  However, in the configuration shown in Patent Document 1, there are a step of mounting the sensor element in the case and a step of mounting the case provided with the sensor element in the storage unit, and a plurality of mounting steps for the sensor element in the device are performed. I need it. This complicates the manufacturing process and increases the cost.

Patent Document 2 below discloses an invention related to an acceleration sensor.
In the acceleration sensor shown in Patent Document 2, the semiconductor sensor element 2 is supported by the base substrate 3 and is housed in the package 11 in a state in which the semiconductor sensor element 2 is erected. The cover 13 is covered. A plurality of protruding leg portions 12d are provided on the bottom surface of the package 11, and the acceleration sensor is mounted by inserting the leg portions 12d into the circuit board PL.

However, as in the invention described in Patent Document 2, in the configuration in which the leg portion 12d is inserted and mounted on the circuit board, mounting is performed in a separate process from other surface mount components, and thus the number of processes increases, and High cost. Further, in Patent Document 2, there are a process of mounting the semiconductor sensor element 2 on the base substrate 3 and a process of mounting the base substrate 3 including the semiconductor sensor element 2 in the package 11. A plurality of mounting processes for the sensor element are performed, and the same problem as in Patent Document 1 occurs.
International Publication No. 2003/046479 Pamphlet Japanese Patent Laid-Open No. 9-318652

  Accordingly, the present invention is to solve the above-described conventional problems, and in particular, an object of the present invention is to provide a physical quantity sensor device that can be mounted on a circuit board by a single mounting process.

A physical quantity sensor device according to the present invention includes a mounting board that is erected on a circuit board in a height direction, and a physical quantity sensor element that is mounted on a vertical surface of the mounting board as viewed from the surface of the circuit board. Have
The bottom surface of the mounting substrate is a mounting surface on the circuit substrate where the electrodes are exposed.

  According to the present invention, the mounting process for the physical quantity sensor element in the physical quantity sensor device is performed only once, and surface mounting can be performed on the circuit board.

  In the present invention, the mounting board includes a first board mounted on the circuit board and a second board erected on the surface of the first board, and is viewed from the surface of the first board. It is preferable that the physical quantity sensor element is mounted on a vertical surface of the second substrate, and a bottom surface of the first substrate is the mounting surface on the circuit board. As a result, the mounting board can be reliably mounted on the circuit board, and a stable standing state of the mounting board can be obtained.

In the present invention, the first substrate and the second substrate can be integrally formed.
In the present invention, it is preferable that a concave portion is formed in the mounting substrate, and an IC electrically connected to the physical quantity sensor element is accommodated in the concave portion. Thereby, the IC can be appropriately mounted on the mounting substrate.

  Moreover, it is preferable that the said recessed part is formed in the said perpendicular | vertical surface. At this time, by mounting the IC in the recess, the IC installation does not interfere with the mounting of the physical quantity sensor element.

In the present invention, a sensor side connection part electrically connected to the physical quantity sensor element, an IC side first connection part electrically connected to the IC, and an IC side second connection part are formed on the vertical surface. From the bottom to the height direction, the IC side second connection part, the IC side first connection part, and the sensor side connection part are formed in this order,
A first wiring pattern that electrically connects the sensor side connection portion and the IC side first connection portion, and a second wiring pattern that electrically connects the IC side second connection portion and the electrode, It is preferable that they are arranged in parallel in the height direction. As a result, the first wiring pattern and the second wiring pattern can be appropriately separated, so that the crosstalk resistance of the signal can be improved and the mounting area of the vertical surface can be reduced.

  In the present invention, the physical quantity sensor is a gyro sensor for detecting an angular velocity around an axis in the height direction, including a vibrator having at least two arm portions and a base portion connecting the arm portions. Suitable for configuration.

  According to the physical quantity sensor element device of the present invention, the mounting process for the physical quantity sensor element in the physical quantity sensor device can be performed only once, and surface mounting can be performed on the circuit board.

  1 is a cross-sectional view of a gyro sensor device according to a first embodiment of the present invention (a cross-sectional view taken along the line AA in FIG. 2 and viewed from the direction of the arrow), and FIG. 2 is a gyro according to the first embodiment. FIG. 3 is a bottom view of the gyro sensor device of the first embodiment, FIG. 4 is a front view of the gyro sensor device with a cover removed from the gyro sensor device shown in FIG. 2, and FIG. FIG. 6 is a rear view of the gyro sensor device of the first embodiment, FIG. 6 is a front view of the gyro sensor device of the second embodiment of the present invention (showing a cover removed), and FIG. 7 is a tuning fork constituting the gyro sensor device. FIG. 8 is an enlarged sectional view of the tuning fork vibrator viewed from the direction of the arrow cut along the line BB shown in FIG.

  The X-axis direction and the Y-axis direction in each figure refer to two orthogonal directions on the horizontal plane. The Z-axis direction indicates a height direction (vertical direction) orthogonal to the X-axis direction and the Y-axis direction. 2 and 4, the X-axis direction is the width direction of the gyro sensor device when the gyro sensor device 1 is viewed from the front, and the Y-axis direction indicates the depth direction of the gyro sensor device.

  A gyro sensor device 1 shown in FIG. 1 includes a mounting substrate 2, a gyro sensor element 3, an IC 4, and a cover 5.

  The mounting board 2 includes a first board 7 mounted on the circuit board 6 and a second board 8 erected on the surface 7 a of the first board 7. In the form shown in FIG. 1, the first substrate 7 and the second substrate 8 are integrated. The first substrate 7 and the second substrate 8 are, for example, resin molded products.

  As shown in FIG. 1, the cross-sectional shape of the mounting substrate 2 viewed from the side is substantially L-shaped, but the shape is not limited. However, as shown in FIG. 1, the length dimension of the first substrate 7 in the depth direction (Y-axis direction) is larger than the length dimension (thickness dimension) of the second substrate 8 in the depth direction (Y-axis direction). By forming and forming a mounting area of the first substrate 7 with the circuit board 6 wide, the mounting board 2 can be reliably mounted on the circuit board 6. Further, the mounting substrate 2 in the standing state shown in FIG. 1 can be obtained stably.

  As shown in FIGS. 1 and 4, the second substrate 8 is provided with a vertical surface 8 a extending in the height direction (Z-axis direction) when viewed from the surface 7 a of the first substrate 7. The vertical surface 8a is a surface parallel to the XZ plane, and is formed as a flat surface except for a concave portion 8b described later. The planar shape of the vertical surface 8a is preferably a rectangular shape, but other planar shapes are not excluded.

  As shown in FIGS. 1 and 4, the gyro sensor element 3 is directly mounted on the vertical surface 8 a of the second substrate 8.

  As shown in FIGS. 1, 4, and 7, the gyro sensor element 3 vibrates the vibrator 12, the pedestal portion 13, and the vibrator 12 in a predetermined direction, and the vibrator 12 receives Coriolis force. And a piezoelectric functional element 14 for detecting the amount of displacement.

  The vibrator 12 is preferably formed by processing a Si substrate. In this embodiment, the vibrator 12 is a tuning fork vibrator, but may be a sound piece vibrator.

  As shown in FIG. 7, the vibrator 12 has two arm portions 15 and 16 (first arm portion 15 and second arm portion 16) that extend long in the Z-axis direction with a predetermined interval in the X-axis direction, and these arms. It has a base portion (connecting portion) 17 that connects one end portions of the portions 15 and 16.

  The base portion 17 is formed thicker than the arm portions 15 and 16 and also functions as the pedestal portion 13. The base portion 17 may be formed with substantially the same thickness as the arm portions 15 and 16, and the base portion 13 may be separately provided on the back surface of the base portion 17.

  By mounting the pedestal portion 13 on the vertical surface 8a of the second substrate 8, the arm portions 15 and 16 of the vibrator 12 are supported in a state separated from the vertical surface 8a as shown in FIG.

  As shown in FIG. 7, the piezoelectric functional element 14 is formed from the arm portions 15 and 16 to the base portion 17. Hereinafter, the form of the piezoelectric functional element 14 will be described.

  As shown in FIG. 7, the first drive unit 18 and the second drive unit 19 provided on the first arm unit 15 so as to be spaced apart from each other in the X-axis direction and the drive units 18 and 19 are provided apart from each other. The detected unit 20 is provided.

  As shown in FIG. 8, the first driving unit 18 and the second driving unit 19 are composed of lower electrodes 18a and 19a from the bottom, for example, piezoelectric films 18b and 19b made of PZT and polarized in the Y-axis direction, and upper electrodes ( Drive electrodes) are stacked in the order of 18c and 19c.

  Further, as shown in FIG. 8, the detection unit 20 is laminated in order of a lower electrode 20a from the bottom, for example, a piezoelectric film 20b made of PZT and polarized in the Y-axis direction, and an upper electrode (detection electrode) 20c. .

  The detection unit 20 is provided along the Z-axis direction at a substantially central position in the X-axis direction (width direction) of the arm unit 15, and each drive unit 18, 19 is moved from the detection unit 20 in the X-axis direction (width direction). ) At substantially equal intervals along the Z-axis direction.

  As shown in FIG. 7, the same piezoelectric functional element 14 as the first arm portion 15 is also formed on the second arm portion 16 side. The piezoelectric functional element 14 formed on the first arm portion 15 and the piezoelectric functional element 14 formed on the second arm portion 16 are in the Z-axis direction between the first arm portion 15 and the second arm portion 16. It is formed in a line symmetrical relationship with the center line as the axis of symmetry.

  As shown in FIG. 7, a common ground 25 connected to each lower electrode is formed on the base 17 of the vibrator 12.

  As shown in FIG. 7, the upper electrode 18 c of the first drive unit 18 formed on the first arm unit 15 and the upper electrode 18 c of the first drive unit 18 formed on the second arm unit 16 are the base 17. It is pulled out to the top and connected to the common electrode pad 21 on the piezoelectric film 26 of the base 17.

  Further, as shown in FIG. 7, the upper electrode 19 c of the second driving unit 19 formed on the first arm unit 15 and the upper electrode 19 c of the second driving unit 19 formed on the second arm unit 16 are the base 17. It is pulled out to the top and connected to the common electrode pad 22 on the piezoelectric film 26 of the base 17.

  Further, as shown in FIG. 7, the upper electrode 20 c of the detection unit 20 formed on the first arm unit 15 and the upper electrode 20 c of the detection unit 20 formed on the second arm unit 16 are respectively formed on the base 17. To the electrode pads 23 and 24 on the base 17.

  Drive vibrations having phases opposite to each other are supplied to the electrode pads 21 and 22 from the drive circuit. At this time, for example, when the piezoelectric film 18b of the first drive unit 18 contracts in the Z-axis direction, the piezoelectric film 19b of the second drive unit 19 extends in the Z-axis direction. As a result, the arm portions 15 and 16 are bent in the X-axis direction in the opposite phase to cause tuning fork vibration.

  As described above, when the vibrator 12 vibrates in the tuning fork in the X-axis direction, when the angular velocity Ω around the Z-axis is applied to the gyro sensor element 3, the arms 15 and 16 are moved in the Y-axis direction by Coriolis force. Displaces in opposite phase. The displacement amount of each arm part 15 and 16 at this time is detected by the upper electrode 20c of the detection part 20 provided in each arm part 15 and 16. The charges detected by the upper electrodes 20c of the arm portions 15 and 16 have opposite polarities, and these charges are guided to the electrode pads 23 and 24, respectively. Then, signal processing is performed by an IC 4 including a differential amplifier connected to each electrode pad 23, 24, and an angular velocity signal is output.

  The form of the gyro sensor element 3 shown in FIGS. 7 and 8 is only one form. For example, a form in which a support plate is provided below the pedestal portion 13 and this support plate is mounted on the vertical surface 8a may be used.

  As shown in FIG. 4, a plurality of sensor side connection portions 30 are provided on the vertical surface 8 a near the base portion 17 of the vibrator 12, and between the sensor side connection portions 30 and the electrode pads of the vibrator 12. Are electrically connected by wire bonding, for example.

  As shown in FIGS. 1 and 4, a concave portion 8 b is formed on a vertical surface 8 a on the first substrate 7 side (downward direction in the drawing) from the base portion 17 of the vibrator 12. Since the portion of the base portion 17 is a mounting position (fixed position) on the vertical surface 8a, the concave portion 8b is formed on the vertical surface 8a at a position away from the gyro sensor element 3. IC4 is accommodated in the recess 8b. A plurality of IC side first connection portions 31 and IC side second connection portions 32 are provided on the vertical surface 8a in the vicinity of the IC 4.

  As shown in FIG. 4, the IC-side first connection portion 31 is located closer to the first substrate 7 than the sensor-side connection portion 30, but is located farther from the first substrate 7 than the IC-side second connection portion 32. is there. That is, the IC-side second connection portion 32, the IC-side first connection portion 31, and the sensor-side connection portion 30 are provided in this order from the bottom toward the top in the figure.

  The IC 4 and the IC side first connection part 31 and the IC side second connection part 32 are electrically connected, for example, by wire bonding. The IC 4 is embedded in the recess 8b with a potting resin 38 or the like.

  As shown in FIG. 4, the sensor side connection part 30 and the IC side first connection part 31 are electrically connected by a first wiring pattern 33. The first wiring pattern 33 is formed of a conductive material on the vertical surface 8a by sputtering or plating.

  On the other hand, the second wiring pattern 34 is electrically connected to the IC-side second connection portion 32. The second wiring pattern 34 is electrically connected to an electrode 35 provided exposed on the bottom surface 36 of the mounting substrate 2 (first substrate 7) shown in FIG. The electrode 35 has a flat plate shape and is formed on the flat bottom surface 36 with a thin film thickness.

  In the present embodiment, among the plurality of second wiring patterns 34, half of the second wiring patterns 34 extend to the electrode 35 through the vertical surface 8 a that is the front surface of the mounting substrate 2, and the remaining half of the second wiring patterns 34. As shown in FIGS. 4 and 5, the two wiring pattern 34 is passed through the back surface of the mounting substrate 2 through the via hole 37 and extends from the back surface to the electrode 35.

  The cover 5 is used for preventing dust from entering and preventing external contact with the gyro sensor element 3. The cover 5 is a metal cover, for example. In addition, although installation of the cover 5 is not essential, it is preferable to provide it.

  A characteristic configuration of the gyro sensor device 1 in the present embodiment is that a mounting board 2 is provided on a circuit board 6 so as to be erected in the height direction (Z-axis direction), and a gyro sensor is provided on a vertical surface 8 a of the mounting board 2. The element 3 is directly mounted, and the bottom surface 36 of the mounting substrate 2 is a mounting surface to the circuit substrate 6 where the electrodes 35 are exposed.

  In the present embodiment, with the above-described configuration, the mounting process for mounting the gyro sensor element 3 in the gyro sensor device 1 in a state where the gyro sensor element 3 stands in the height direction (Z-axis direction) Only one mounting is required directly on the vertical surface 8a, and there is no need to perform a plurality of times as in the prior art. Moreover, the gyro sensor device 1 can be surface-mounted on the circuit board 6. As described above, in the gyro sensor device 1 in which the gyro sensor element 3 is mounted upright in the height direction (Z-axis direction) as compared with the prior art, the mounting process of the gyro sensor element 3 is not complicated, and other surface mounting is performed. The gyro sensor device 1 can be mounted on the circuit board 6 in the same process as the parts, and the manufacturing cost can be reduced.

  In the present embodiment, the concave portion 8b is formed in the mounting substrate 2, and the IC 4 is accommodated in the concave portion 8b, so that the gyro sensor device 1 can be securely fixed and supported in a limited space while being miniaturized. Considering the electrical connection with the gyro sensor element 3, it is preferable to provide the IC 4 together with the gyro sensor element 3 on the vertical surface 8a. At this time, since the recess 8b is formed in the vertical surface 8a and the IC 4 is accommodated in the recess 8b, the installation of the IC 4 on the vertical surface 8a does not interfere with the mounting of the gyro sensor element 3. Further, when the concave portion 8b is formed on the vertical surface 8a, the concave portion 8b is formed at the position of the vertical surface 8a facing the arm portions 15 and 16, thereby increasing the area of the vertical surface 8a without increasing the area of the vertical surface 8a. Can be reduced in size.

  Further, by defining the arrangement in the height direction (Z-axis direction) of the sensor side connection part 30, the IC side first connection part 31, and the IC side second connection part 32 as shown in FIG. The first wiring pattern 33 that electrically connects the part 30 and the IC side first connection part 31 and the second wiring pattern 34 that electrically connects the IC side second connection part 32 and the electrode 35 that appears on the bottom surface 36. Can be juxtaposed in the height direction (Z-axis direction).

  That is, FIG. 6 is also an aspect of the present embodiment, but in FIG. 6, the sensor-side connection portion 30, the IC-side first connection portion 31, and the IC-side second portion are directed from the first substrate 7 side upward in the drawing. The connection portions 32 are formed in this order. In such a case, the first wiring pattern 33 that electrically connects the sensor side connection part 30 and the IC side first connection part 31, and the second wiring line that electrically connects the IC side second connection part 32 and the electrode 35. The wiring patterns 34 cannot be arranged side by side in the height direction, and are in an arrangement relationship facing the width direction (X-axis direction), so that the first wiring pattern 33 and the second wiring pattern 34 are close to each other.

  In FIG. 4, the first wiring pattern 33 and the second wiring pattern 34 extend away from the IC side connection portions 31 and 32, but in the form of FIG. 6, the first wiring pattern 33 and the second wiring pattern 34 Since the wiring pattern 34 is more likely to be closer than in the form of FIG. 4, crosstalk resistance between a minute detection signal from the gyro sensor element 3 toward the IC 4 and a signal amplified by the IC 4 is reduced. In the embodiment of FIG. 6, the distance between the first wiring pattern 33 and the second wiring pattern 34 facing each other in the width direction can be increased by increasing the width direction (X-axis direction) dimension of the vertical surface 8a. However, the area (mounting area) of the vertical surface 8a is increased, and the gyro sensor device 1 cannot be reduced in size.

  Therefore, by using the form of FIG. 4 compared to the form of FIG. 6, the crosstalk resistance of the signal can be improved, and the gyro sensor device 1 can be downsized.

  In the manufacturing method of the gyro sensor device 1 according to the present embodiment, the vertical surface 8a is provided, and the sensor side connection portion 30, the IC side first connection portion 31, the IC side second connection portion 32, the first wiring pattern 33, and the second. The mounting substrate 2 on which the wiring pattern 34 is formed is formed. A flat electrode 35 is formed on the planar bottom surface 36 of the mounting substrate 2 by sputtering or plating, and the bottom surface 36 is used as a mounting surface for the circuit substrate 6. Subsequently, the IC 4 is mounted on the mounting substrate 2. At this time, it is preferable to form a recess in the mounting substrate 2 and house the IC 4 in the recess. Subsequently, the gyro sensor element 3 is directly mounted on the vertical surface 8 a of the mounting substrate 2. Subsequently, the gyro sensor element 3 and the connection part 30 and the IC 4 and the connection parts 31 and 32 are electrically connected by wire bonding or the like. Finally, the cover 5 is put on. According to the manufacturing method of the gyro sensor device 1 of the present embodiment, the mounting process of the gyro sensor element 3 in the device is only required once. Since the bottom surface 36 can be used as a mounting surface on the circuit board 6, the gyro sensor device 1 can be easily mounted on the circuit board 6 in the same process as other surface mounting components.

  In the above embodiment, the gyro sensor device 1 has been described. However, the present invention can also be applied to other physical quantity sensor devices (such as a pressure sensor and an acceleration sensor) that are mounted with the physical quantity sensor elements standing.

Sectional drawing (sectional drawing cut | disconnected along the AA line of FIG. 2 and seen from the arrow direction) of the gyro sensor apparatus of 1st Embodiment of this invention, The front view of the gyro sensor device of a 1st embodiment, A bottom view of the gyro sensor device of the first embodiment, FIG. 2 is a front view of the gyro sensor device with a cover removed from the gyro sensor device shown in FIG. The back view of the gyro sensor device of a 1st embodiment, A front view of the gyro sensor device of the second embodiment of the present invention (showing a state where the cover is removed), An enlarged plan view of a tuning fork type vibrator constituting the gyro sensor device, FIG. 7 is an enlarged cross-sectional view of a tuning fork vibrator viewed from the direction of the arrow cut along the line BB shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gyro sensor apparatus 2 Mounting board 3 Gyro sensor element 5 Cover 6 Circuit board 7 1st board 8 2nd board | substrate 8a Vertical surface 8b Recessed part 12 Vibrator 14 Piezoelectric functional element 15, 16 Arm part 17 Base part 30 Sensor side connection part 31, 32 IC side connection part 33 1st wiring pattern 34 2nd wiring pattern 35 Electrode 36 Bottom face

Claims (7)

A mounting board that is erected on the circuit board in the height direction, and a physical quantity sensor element that is mounted on a vertical surface of the mounting board when viewed from the surface of the circuit board,
The physical quantity sensor device according to claim 1, wherein a bottom surface of the mounting substrate is a mounting surface on the circuit substrate from which an electrode is exposed.   The mounting board includes a first board mounted on the circuit board and a second board erected on the surface of the first board, and the second board as viewed from the surface of the first board. The physical quantity sensor device according to claim 1, wherein the physical quantity sensor element is mounted on a vertical plane, and a bottom surface of the first substrate is the mounting surface on the circuit board.   The physical quantity sensor device according to claim 2, wherein the first substrate and the second substrate are integrally formed.   The physical quantity sensor device according to claim 1, wherein a concave portion is formed in the mounting substrate, and an IC electrically connected to the physical quantity sensor element is accommodated in the concave portion.   The physical quantity sensor device according to claim 1, wherein the concave portion is formed on the vertical surface. A sensor-side connection portion that is electrically connected to the physical quantity sensor element, an IC-side first connection portion that is electrically connected to the IC, and an IC-side second connection portion are formed on the vertical surface, and have a height from below. In the direction, the IC side second connection part, the IC side first connection part, and the sensor side connection part are formed in this order,
A first wiring pattern that electrically connects the sensor side connection portion and the IC side first connection portion, and a second wiring pattern that electrically connects the IC side second connection portion and the electrode, The physical quantity sensor device according to claim 1, wherein the physical quantity sensor device is arranged in parallel in a height direction.   The physical quantity sensor is a gyro sensor for detecting an angular velocity around an axis in a height direction including a vibrator having at least two arm portions and a base portion connecting the arm portions. The physical quantity sensor device according to any one of the above.

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