JP2012194032A - Sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor device in which deterioration of detection performance is suppressed.SOLUTION: A sensor device comprises: a package body 2 including a bottom surface 2A1 that is inclined at the angle of θ with respect to a mounting surface; an angular velocity sensor element 1 mounted on the bottom surface 2A1; a lead 5 mounted on the package body 2 so as to form a hollow part 2A for housing the angular velocity sensor element 1 on the bottom surface 2A1; and a die bond member 4 lying between the bottom surface 2A1 and the angular velocity sensor element 1 and having flexibility higher than that of the package body 2. The sensor device has a structure in which the lead 5 faces the mounting surface, and a rear surface 2B of the package body 2 extends parallel to a horizontal direction.

Description

  The present invention relates to a sensor device, and more particularly to a sensor device in which a sensor element is mounted on a package body.

  Conventionally, the detection axis of the physical quantity sensor is tilted. The structure in which the detection axis of the physical quantity sensor is inclined is described in, for example, Japanese Patent Application Laid-Open No. 2009-41962 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2008-96420 (Patent Document 2).

  In the angular velocity sensor as the external force detection device described in Patent Document 1, the resin layer (11) is inclined with respect to the surface of the mounting substrate (16), and the angular velocity sensor element (1) is formed on the inclined surface (11a). ) Is installed. For this reason, the detection axis provided so as to be perpendicular to the bottom surface of the angular velocity sensor element is inclined with respect to the mounting surface (16a). The mounting substrate (16) on which the angular velocity sensor element (1) and the IC device (12) are mounted is adhered and fixed inside the concave portion of the ceramic package (14) with an adhesive (17) interposed therebetween. The opening of the recess is sealed with a cap (15) with a sealing material interposed.

  The inertial sensor described in Patent Document 2 includes a lead terminal (3) in a state where the angular velocity detection axis (G) of the gyro sensor (10) is inclined by an angle θ with respect to the normal V on the upper surface of the inertial sensor (1). And is sealed by a resin mold package (2).

Japanese Unexamined Patent Publication No. 2009-41962 JP 2008-96420 A

  In the external force detection device described in Patent Document 1, the semiconductor substrate (41) on which the angular velocity sensor elements (1) are collectively formed has a surface opposite to the surface on which the external electrodes of the angular velocity sensor elements (1) are formed. The resin layer (11) whose upper surface is inclined is integrally formed and divided individually by cutting. Since the thermal expansion coefficient of the resin (11) integrally formed with the angular velocity sensor (1) is significantly different from the thermal expansion coefficient of the angular velocity sensor element (1), stress is applied to the gyro sensor (10). For this reason, there is a problem that the gyro sensor (10) is deformed and a zero point fluctuation occurs. Further, since the electronic circuit of the angular velocity sensor element (1) having the inclined surface and the mounting substrate (16) are electrically connected by wire bonding, there is a problem that productivity is lowered.

  In the inertial sensor described in Patent Document 2, the thermal expansion coefficient differs greatly between the gyro sensor (10), the lead terminal (3), and the resin mold package (2), so that stress is generated in the gyro sensor (10). For this reason, there is a problem that the gyro sensor (10) is deformed and a zero point fluctuation occurs.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sensor device in which deterioration of detection performance is suppressed.

  A sensor device according to the present invention is mounted on a box-shaped package body having a hollow portion, a plurality of lead terminals provided on two opposing side walls of the package body, and a bottom surface of the hollow portion, and has a detection shaft. A sensor element, a lid member attached to the package main body so as to seal the hollow portion, and an adhesive portion interposed between the bottom surface of the hollow portion and the sensor element and having higher flexibility than the package main body. The length of the lead terminal provided on one of the side walls among the plurality of lead terminals is different from the length of the lead terminal provided on the other side of the side wall, so that the detection axis is at an angle θ with respect to the vertical direction. This is a sensor device that satisfies (0 ° <θ <90 °). The sensor device has a structure in which the lid member faces the mounting surface of the sensor device, and the back surface of the package body extends parallel to the mounting surface.

  In one embodiment, the sensor device further includes an IC element mounted in the hollow portion together with the sensor element.

  In one embodiment, in the above sensor device, the adhesive portion includes a silicon-based resin or a fluorine-based resin.

  ADVANTAGE OF THE INVENTION According to this invention, deterioration of the detection performance of a physical quantity sensor can be suppressed.

It is sectional drawing which shows the sensor apparatus which concerns on one embodiment of this invention. FIG. 2 is a cross-sectional view showing a part of a state in which a vibrator substrate and a protective substrate constituting an angular velocity sensor element in the sensor device shown in FIG. 1 are connected. FIG. 2 is a plan view showing a structure of a vibrator substrate used for an angular velocity sensor element in the sensor device shown in FIG. 1.

  Embodiments of the present invention will be described below. Note that the same or corresponding portions are denoted by the same reference numerals, and the description thereof may not be repeated.

  Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential for the present invention unless otherwise specified.

(Structure of sensor device)
FIG. 1 is a cross-sectional view showing a sensor device according to the present embodiment. As shown in FIG. 1, the sensor device according to the present embodiment includes an angular velocity sensor element 1, a package body 2, an Au wire 3, a die bond material 4, a lid 5, a lead terminal 6, and a potting material 7. Including.

  The structure of the angular velocity sensor element 1 will be described later. The package body 2 is made of a synthetic resin material such as polyphenylene sulfide resin (PPS). The lead terminal 6 is made of, for example, a copper-based metal material. The package body 2 and the lead terminals 6 are integrally formed by, for example, insert molding.

  The package body 2 has a rectangular box shape having a hollow portion 2A. An angular velocity sensor element 1 and an IC element (not shown) such as an ASIC that processes a signal from the angular velocity sensor element 1 are bonded and fixed to the bottom surface 2A1 of the hollow portion 2A with a die bond material 4 (adhesive). . As the die bond material 4, for example, a material containing a silicon resin or a fluorine resin having a predetermined flexibility even after curing is used. Even after curing, the die bond material 4 has higher flexibility than the package body 2, the lid 5, a protective substrate 20 described later, and the like. More specifically, the die bond material 4 preferably has a value measured with a Type A durometer in accordance with JIS K6253 of 50 or less. The angular velocity sensor element 1 and the IC element are electrically connected to one end of the lead terminal 6 via the Au wire 3.

  The package body 2 has a back surface 2B. The extending direction of the bottom surface 2A1 of the hollow portion 2A and the extending direction of the back surface 2B form an angle θ. The bottom surface 2A1 of the hollow portion 2A forms an angle θ with respect to the mounting surface, and the back surface 2B extends in parallel with the mounting surface.

  First step portions 8 are provided on the four inner surfaces of the hollow portion 2A. When the lid 5 is fitted to the first step portion 8, the package of the sensor device is sealed. Furthermore, the 2nd step part 9 is provided in the two inner surface which opposes among the four inner surfaces of 2 A of hollow parts. The second step portion 9 is formed inside the first step portion 8 and at a position lower than the first step portion 8 (position close to the back surface 2B of the package body 2). The plurality of lead terminals 6 are provided so as to penetrate the side wall provided with the second step portion 9 of the package body 2. That is, one end of each of the plurality of lead terminals 6 extends outward from two opposing side walls of the package body 2 and is connected to the mounting surface of the circuit board. The other end of the lead terminal 6 is exposed on the second step portion 9 (lower side in FIG. 1). This exposed surface is electrically connected to the Au wire 3.

  A portion of the lead terminal 6 exposed to the outside of the package body 2 has a shape that is once bent downward and further bent outward. The lead terminal 6 on the other side wall side of the package body 2 is longer than the lead terminal 6 on one side wall side of the package body 2, and the bottom surface 2A1 of the hollow portion 2A of the package body 2 is at a predetermined angle with respect to the mounting surface. The lead terminal 6 is bent so as to satisfy θ (0 ° <θ <90 °). Thus, the angle formed by the detection axis of the angular velocity sensor element 1 with respect to the vertical direction is θ. In addition, since a metal mold is used for processing the lead terminal 6, it can be processed with high accuracy.

  By attaching the lid 5 to the package body 2, the hollow portion 2A is sealed. Specifically, a lid 5 made of a synthetic resin such as polyphenylene sulfide resin (PPS) is fitted to the first step portion 8 on the four inner side surfaces of the hollow portion 2A, and bonded by an adhesive or thermocompression bonding. Fixed. The lid 5 may be an integrally formed structure or a structure in which two or more parts are bonded. The material of the lid 5 is not limited to resin, and may be metal.

  The angle formed by the bottom surface 2A1 and the back surface 2B of the hollow portion 2A of the package body 2 is equal to the angle θ described above. Thereby, the back surface 2B of the package body 2 is parallel to the mounting surface. Therefore, the back surface 2B of the package body 2 can be easily sucked by the component suction nozzle of the component mounting apparatus.

  The angular velocity sensor element 1 and the IC element are covered with a potting material 7 made of, for example, a silicon-based resin or a fluorine-based resin material having a predetermined flexibility even after curing in order to relieve external stress. It is desirable. Even after curing, the potting material 7 has higher flexibility than the package body 2, the lid 5, the protective substrate 20 described later, and the like. More specifically, the potting material 7 preferably has a value measured with a Type A durometer in accordance with JIS K6253 of 50 or less. Furthermore, the potting material 7 is preferably a gel-like potting material. Further, it is desirable that the angular velocity sensor element 1 and the IC element are arranged in parallel to one side surface of the lead terminal formation. By doing so, the sensor device as a whole can be further downsized.

(Manufacturing method of sensor device)
Next, a method for manufacturing the sensor device shown in FIG. 1 will be described.

First, a plurality of package bodies 2 are molded at predetermined locations on the lead frame.
Next, a die bond material 4 (adhesive) is applied to the bottom surface of the hollow portion 2A of the package body 2 to die bond the angular velocity sensor element 1 and the IC element.

  Then, wire bonding is performed so that the angular velocity sensor element 1 and the IC element and one end of the lead terminal 6 are electrically connected via the Au wire 3.

  Thereafter, a potting material 7 is applied so as to cover the angular velocity sensor element 1 and the IC element.

  Further, an adhesive is applied to the first step portion 9 of the hollow portion 3 of the package body 2, and the lid 5 is mounted.

  Then, the lead frame is cut using a mold, and the lead terminal 6 is processed to have a predetermined length. Further, the lead terminal 6 is bent so as to have a predetermined shape using a mold.

  The suspension lead is cut, and the sensor device including the package body 2 is separated from the lead frame.

(Structure of angular velocity sensor element 1)
Next, the structure of the angular velocity sensor element 1 will be described. FIG. 2 is a cross-sectional view showing a part of a state in which the vibrator substrate and the protective substrate constituting the angular velocity sensor element are joined. FIG. 3 is a plan view showing the structure of the vibrator substrate used in the angular velocity sensor element.

  An angular velocity sensor element 1 shown in FIG. 2 is an electrostatic drive / capacitance detection type and non-resonance type, for example, a vibrator substrate 10 made of a single-crystal or polycrystal low-resistance silicon material, The vibrator substrate 10 has a protective substrate 20 made of, for example, a high-resistance silicon material or glass material bonded to both the main surface and the back surface. The vibrator substrate 10 and the protective substrate 20 are integrally bonded by a bonding method such as anodic bonding, for example, except for the formation portion of the cavity 30 for securing the movable part of the vibrator substrate 10. A recess is formed in the surface of the protective substrate 20 on both sides of the transducer substrate 10 on the side facing the transducer substrate 10, and a cavity 30 is formed inside the angular velocity sensor element 1. The cavity 30 is maintained in a vacuum state or a low pressure state in order to reduce vibration damping. An opening is formed in one side of the protective substrate 20, and an electrical signal is transmitted to and received from the transducer substrate 10 by forming a film-like electrode 40 in the opening.

  As shown in FIG. 3, the vibrator substrate 10 is formed with first to fourth mass portions 71 to 74, a driving beam 80, and fixing portions 181 and 182 by performing fine processing such as etching. ing. Also, first and second monitor electrodes 91 and 92, first to fourth drive electrodes 101 to 104, first to fourth detection electrodes 161 to 164, and the like are formed.

  Here, in FIG. 3, the longitudinal direction of the vibrator substrate 10 is defined as the Y-axis direction, the transverse direction perpendicular thereto is defined as the X-axis direction, and the direction perpendicular to the paper surface perpendicular to both axes is defined as the Z-axis direction. The first to fourth mass parts 71 to 74 are supported in series along the Y-axis direction by the drive beam 80, whereby the first to fourth mass parts 71 to 74 are arranged in the X-axis direction. It is possible to vibrate along. That is, the first to fourth mass parts 71 to 74 are movable parts, and the first and second monitor electrodes 91 and 92 and the first to fourth drive electrodes 101 to 104 are fixed parts. Yes.

  The first mass portion 71 includes a comb-like movable side electrode that protrudes left and right so as to face the first monitor electrode 91 and the comb-like portions of the first and second drive electrodes 101 and 102. 111a, 111b, and 111c are provided.

  The second mass unit 72 includes a first detection frame 141 having a shape in which a rectangular first drive frame 121 supported by the drive beam 80 and two rectangles supported by the upper and lower first detection beams 131 are connected to each other. And have. On the outside of the first drive frame 121, comb-shaped movable electrodes 151a and 151b that are close to the first mass portion 71 and face the comb-shaped portions of the first and second drive electrodes 101 and 102 described above. Is formed. In addition, comb-shaped movable side electrodes 171 are formed on the inner sides of the two quadrangular portions of the first detection frame 141 so as to face the comb-shaped first and second detection electrodes 161 and 162, respectively. Yes. As a result, the first detection frame 141 can be vibrated along the Y-axis direction by the first detection beam 131 together with the movable electrode 171.

  The fourth mass portion 74 includes a comb-like movable side electrode that protrudes left and right so as to face the comb-like portions of the second monitor electrode 92 and the third and fourth drive electrodes 103 and 104. 112a, 112b, and 112c are provided.

  The third mass portion 73 includes a rectangular second drive frame 122 supported by the drive beam 80 and a second detection frame 142 having a shape in which two squares supported by the upper and lower second detection beams 132 are connected to each other inside the second detection frame 142. And have. On the outside of the second drive frame 122, comb-shaped movable electrodes 152a and 152b that are close to the fourth mass portion 74 and face the comb-shaped portions of the third and fourth drive electrodes 103 and 104 described above. Is formed. In addition, comb-shaped movable side electrodes 172 are formed inside the two quadrangular portions of the second detection frame 142 so as to face the comb-shaped third and fourth detection electrodes 163 and 164, respectively. Yes. As a result, the second detection frame 142 can be vibrated along the Y-axis direction by the second detection beam 132 together with the movable electrode 172.

  The Z axis perpendicular to the plane of the transducer substrate 10 is the angular velocity detection axis. The angular velocity around the detection axis (Z axis) perpendicular to the transducer substrate 10 can be detected by the displacement of the transducer substrate 10 due to the vibration in the Y-axis direction. That is, the angular velocity sensor element 1 outputs an output signal (capacitance change) according to the rotational angular velocity with the Z-axis direction shown in FIG.

(Function and effect)
As described above, as the angular velocity sensor element 1 according to the present embodiment, a driving unit and a detection unit having an interdigital structure are formed on a single crystal Si substrate (vibrator substrate 10) using a fine processing technique. An angular velocity sensor element having a so-called MEMS structure in which a drive unit and a detection unit are sandwiched between glass substrates (protective substrate 20) so as to be hollow is used. When stress due to an external factor is generated in such an angular velocity sensor element 1, zero point fluctuation (a state in which an error signal is generated due to deformation or warping of the sensor chip even though the angular velocity is not generated) occurs. Therefore, it is important to suppress the stress in the angular velocity sensor element 1.

  On the other hand, in the sensor device according to the present embodiment, since the bottom surface of the hollow portion 2A of the package body 2 is inclined with respect to the mounting surface, the angular velocity is used as a pedestal for inclining the detection axis of the angular velocity sensor element 1. No resin or lead terminal that contacts the sensor element 1 is required. Therefore, a material having relatively high flexibility can be interposed as the die bond material 4 and the potting material 7 between the angular velocity sensor element 1 and the package body 2. Thereby, generation | occurrence | production of the stress in the angular velocity sensor element 1 can be suppressed, and deterioration of detection performance can be suppressed.

  Furthermore, since the angle formed between the bottom surface 2A1 and the back surface 2B of the hollow portion 2A of the package body 2 is equal to the inclination angle θ of the bottom surface 2A1 with respect to the mounting surface, the back surface 2B of the package body 2 is in relation to the mounting surface. Become parallel. Therefore, the back surface 2B of the package body 2 can be easily sucked by the component suction nozzle of the component mounting apparatus.

(Summary)
The above contents are summarized as follows. That is, the sensor device according to the present embodiment includes a package body 2 having a bottom surface 2A1 inclined at an angle θ with respect to the mounting surface, an angular velocity sensor element 1 mounted on the bottom surface 2A1, and an angular velocity on the bottom surface 2A1. A lid 5 as a “lid member” attached to the package body 2 so as to form a hollow portion 2A for housing the sensor element 1, a plurality of lead terminals 6, a bottom surface 2A1, and the angular velocity sensor element 1 are interposed. And a die bond material 4 as an “bonding portion” having higher flexibility than the package body 2. In the sensor device, the length of the lead terminal 6 provided on one of the side walls out of the plurality of lead terminals 6 is different from the length of the lead terminal 6 provided on the other side of the side wall. Is at an angle θ (0 ° <θ <90 °) with respect to the vertical direction (direction perpendicular to the mounting surface). The sensor device has a structure in which the lid 5 faces the mounting surface, and the back surface 2B of the package body 2 extends parallel to the mounting surface.

  In the present embodiment, the example in which the potting material 7 is provided so as to cover the angular velocity sensor element 1 is described, but the potting material 7 may not be provided.

  Moreover, although silicon-type resin or fluorine-type resin was mentioned as an example of the raw material of the die-bonding material 4 and the potting material 7, the raw material of the die-bonding material 4 and the potting material 7 is not limited to these, but has predetermined | prescribed flexibility If so, it can be arbitrarily changed.

  Further, in the present embodiment, the angular velocity sensor element 1 has been described as an example of the “sensor element”. However, the sensor element (sensor chip) of the present invention is not limited to the angular velocity sensor element 1, and for example, an acceleration sensor element or the like The physical quantity sensor element having the same problem may be used.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Angular velocity sensor element, 2 package body, 2A hollow part, 2B back surface, 3 Au wire, 4 die bond material, 5 lid, 6 lead terminal, 7 potting material, 8 1st step part, 9 2nd step part, 10 vibrator Substrate, 20 protective substrate, 30 cavities, 40 electrodes, 71, 72, 73, 74 parts by mass, 80 driving beams, 91, 92 monitor electrodes, 101, 102, 103, 104 driving electrodes, 111a, 111b, 111c, 112a, 112b, 112c movable electrode, 121, 122 drive frame, 131, 132 detection beam, 141, 142 detection frame, 151a, 151b, 152a, 152b, 171, 172 movable electrode, 161, 162, 163, 164 detection electrode, 181 and 182 fixing parts.

Claims (3)

A box-shaped package body having a hollow portion;
A plurality of lead terminals provided on two opposing side walls of the package body;
A sensor element mounted on the bottom surface of the hollow portion and having a detection axis;
A lid member attached to the package body so as to seal the hollow portion;
An adhesive portion interposed between the bottom surface of the hollow portion and the sensor element, and having a higher flexibility than the package body,
Among the plurality of lead terminals, the length of the lead terminal provided on one of the side walls is different from the length of the lead terminal provided on the other side of the side wall, so that the detection axis is perpendicular to the vertical direction. A sensor device having an angle θ (0 ° <θ <90 °),
The lid member has a structure facing the mounting surface of the sensor device;
A sensor device, wherein a back surface of the package body extends parallel to the mounting surface.   The sensor device according to claim 1, further comprising an IC element mounted in the hollow portion together with the sensor element.   The sensor device according to claim 1, wherein the adhesion portion includes a silicon-based resin or a fluorine-based resin.

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