JP2007040965A - Sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor device for dramatically enhancing the flexibility of installation in a limited space, in particular, in regard to the disposition of a rotation sensor and an acceleration sensor. <P>SOLUTION: This sensor device is equipped with: a first sensor chip 10 comprising magnetoresistive elements MRE1 to MRE4; a second sensor chip 20 comprising an acceleration detection element; a lead frame 60 where these first and second sensor chips 10 and 20 are mounted; and a magnet 30 for giving a bias magnetic field to the magnetoresistive elements MRE1 to MRE4 of the sensor chip 10. Among them, the sensor chips 10 and 20 are disposed in a form hermetically closed by a cover member 40 and a lid material 50 to isolate them from external atmosphere. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sensor device used for detecting rotational speed and acceleration.

  As is well known, many sensors are mounted on the vehicle, and various information necessary for vehicle control is detected through these sensors. Among such sensors, there are a rotation sensor used for detecting the rotation speed and rotation angle of various rotating bodies, and an acceleration sensor used for detecting various accelerations generated in the vehicle. Among these, as the rotation sensor, one that detects the rotation mode of the rotating body using, for example, the resistance value change of the magnetoresistive element following the rotation of the rotating body is known. Widely used for wheel rotation speed (wheel speed). Incidentally, when this rotation sensor is used for detecting the wheel speed, it is usually provided in a mode of detecting the rotation of a rotor that is provided in the vicinity of the wheel and that can rotate integrally with the wheel shaft ( For example, see Patent Document 1).

On the other hand, as the acceleration sensor, for example, a capacitance type, a strain gauge type (piezoresistive type), a piezoelectric type and the like are known, and are widely used for detecting acceleration in the vertical direction and the front-rear direction of the vehicle, for example. ing. The detected acceleration is used, for example, for vehicle brake control, airbag control, suspension control, or the like. When this acceleration sensor is used particularly for vehicle suspension control, it may be used to monitor information indicating flickering of the vehicle, which is information required for the suspension control. The acceleration sensor is also usually disposed in the vicinity of the wheel.
JP-A-7-333236

  By the way, in the case of using the rotation sensor for detecting the wheel speed and the acceleration sensor for monitoring the fluttering of the vehicle, these sensors are both disposed in the vicinity of the wheel, so that the wiring and the like are taken into consideration. Then, it is desirable to arrange these sensors as close as possible. However, since these rotation sensors and acceleration sensors are each formed as a single assembly (structure) and their mounting modes are different, both of these sensors are provided in a limited arrangement space near the wheel. It is difficult to arrange the sensors close to each other, and ultimately, the degree of freedom regarding the mounting of these sensors is greatly limited.

  It should be noted that the present invention is not limited to the rotation sensor used for detecting the wheel speed and the acceleration sensor used for monitoring the flickering of the vehicle. Limitation of freedom is inevitable.

  The present invention has been made in view of such circumstances, and the object thereof is a sensor that can greatly increase the degree of freedom in mounting in a limited space, particularly with regard to the arrangement of the rotation sensor and the acceleration sensor. To provide an apparatus.

  In order to achieve such an object, according to the first aspect of the present invention, a first sensor chip having a magnetoresistive element, a second sensor chip having an acceleration detecting element, and the first and second sensor chips are provided. A lead frame to be mounted and a magnet for applying a bias magnetic field to the magnetoresistive element of the first sensor chip are provided, and at least the first and second sensor chips should be shielded from the external atmosphere. A change in a magnetic vector, which is arranged in a sealed housing and is generated in cooperation with the bias magnetic field when the rotor rotates in the vicinity of the first sensor chip, is detected as a change in the resistance value of the magnetoresistive element. And detecting the rotation mode of the rotor and detecting the acceleration acting on the housing on the acceleration detecting element provided on the second sensor chip. It was to be detected in conjunction through.

  According to the above configuration, since the first sensor chip having the magnetoresistive element and the second sensor chip having the acceleration detecting element are arranged in the housing and integrated into one, the sensor device is arranged. Such a space is sufficient for one sensor, and the degree of freedom for mounting in a limited space can be greatly increased.

  Further, in the sensor device according to claim 1, for example, in the invention according to claim 2, at least the first sensor chip is mounted in a bare chip state on the mounting surface of the lead frame, and is used for power supply. The frame portion is shared by the first and second sensor chips.

  According to such a configuration, at least the first sensor chip is mounted on the mounting surface of the lead frame in a bare chip state, that is, without being subjected to resin molding or the like. It can be mounted together with the chip. In addition, in this case, the first sensor chip (more precisely, the magnetoresistive element) can be brought closer to a stronger part of the magnetic force such as the inner wall or the tip of the magnet, and the bias magnetic field stronger than the magnetoresistive element. Can be granted. In addition, since the lead frame portion used for power feeding is shared by the first and second sensor chips, the necessary lead frame can be minimized, so that the sensor device can be miniaturized. It becomes like this.

Further, in the sensor device according to claim 1 or 2, when the first and second sensor chips are arranged in the housing, for example, according to the invention according to claim 3,
(A) The housing is configured to have a bottomed cylindrical cover member made of a nonmagnetic material and a lid member made of an insulating material and closing the opening end of the cover member, A plate-like tongue portion in which a mounting surface of the lead frame and the first and second sensor chips is integrally cast, the material extending in a manner protruding inward of the cover member In addition, the lead portion of the lead frame that is also used as a terminal is formed as a structure led out from the back surface of the lid member, and the magnet is formed in a cylindrical shape having a hollow portion so that the inside of the housing is formed. A structure disposed on the bottom surface and disposed in the housing so as to be accommodated in the hollow portion of the magnet in a state where at least the first sensor chip is mounted on the distal end side of the tongue portion forming the lid structure. .
Alternatively, as in the invention according to claim 4,
(B) The housing is configured to have a bottomed cylindrical cover member made of a non-magnetic material and a lid member made of an insulating material that closes the opening end of the cover member. A plate-like tongue portion in which a mounting surface of the lead frame and the first and second sensor chips is integrally cast, the material extending in a manner protruding inward of the cover member The lead portion of the lead frame that is also used as a terminal is formed as a structure derived from the back surface of the lid member, and the magnet is used as the lead of the tongue portion that forms the lid member structure. The frame and the first sensor chip are disposed on the back surface of the surface on which the mounting surface is provided, and the first and second sensor chips are mounted on the tongue portion forming the lid material structure. A structure that is arranged in the housing.
Further, according to the invention of claim 5,
(C) The housing is configured to have a bottomed cylindrical cover member made of a non-magnetic material and a lid member made of an insulating material that closes the opening end of the cover member. A plate-like tongue portion in which a mounting surface of the lead frame and the first and second sensor chips is integrally cast, the material extending in a manner protruding inward of the cover member In addition, a lead portion of the lead frame that is also used as a terminal is formed as a structure derived from the back surface of the lid member, and the magnet is formed in a cylindrical shape having a hollow portion and is attached to the housing. A structure that is fitted and disposed in the housing in a state in which at least the first sensor chip is mounted on the distal end side of the tongue that forms the lid member structure.
And so on.

  By adopting one of these configurations, the lid member structure on which the first sensor chip and the second sensor chip are mounted is assembled to the cover member, so that the first sensor chip can be easily used. In addition, the second sensor chip can be disposed in a sealed manner in the housing while being shielded from the external atmosphere. Moreover, in the structure of Claim 4, since a magnet is reduced in size, the said sensor apparatus can also be reduced in size.

  Further, in the sensor device according to any one of claims 3 to 5, for example, according to the invention according to claim 6, the front end surface of the tongue portion forming the lid member structure is formed on the inner side of the cover member. By bonding and fixing to the bottom surface, the rigidity of the tongue can be increased. In addition, since the vibration of the tongue portion on which the first and second sensor chips are mounted is suppressed, the influence of the vibration on the sensing characteristics of the first and second sensor chips is preferably suppressed. .

  By the way, the side inner wall portion or the tip portion of the magnet is a portion capable of applying a stronger bias magnetic field to the first sensor chip (more precisely, the magnetoresistive element) than other portions. is there. Therefore, in order to apply a stronger bias magnetic field to the first sensor chip, that is, to increase the resistance value change of the magnetoresistive element, the first sensor chip is connected to the side inner wall portion or the tip of the magnet. It is desirable to be closer to the part. However, for example, if the first sensor chip is arranged so that the magnetoresistive element is located at the end of the tongue, the distance from the side inner wall or the tip of the magnet is reduced. It is necessary to match the size of the first sensor chip with the width of the tongue, which may increase the chip size of the first sensor chip and thus reduce the yield.

  In that respect, in the sensor device according to any one of claims 3 to 6, for example, according to the invention according to claim 7, the width of the tip portion of the tongue portion forming the lid member structure is set to If it is formed narrower than the base end part of the part, the distance between the first sensor chip and the inner side wall part or the tip part of the magnet is reduced without increasing the chip size of the first sensor chip. It becomes possible. That is, it is possible to increase the change in the resistance value of the magnetoresistive element while suppressing a decrease in the yield of the first sensor chip, and thus it is possible to improve the detection accuracy related to the rotation mode of the rotor. . In addition, if it uses with the structure of the said invention of the said Claim 3 and the said Claim 5, the above-mentioned effect will become more remarkable.

  Further, when the lead frame and the first and second sensor chips are mounted on the tongue portion forming the lid structure, a mounting facility is used, so that the mounting is expensive. Positioning accuracy is required.

  In that regard, in the sensor device according to any one of claims 3 to 7, for example, according to the invention according to claim 8, the lead frame and the first and the first frames of the tongue portion forming the lid member structure. If an alignment mark indicating a reference position is formed on the surface on which the mounting surface of the second sensor chip is provided, the lead frame and the first and second sensors can be formed using the alignment mark as a reference. The chip can be positioned with high accuracy on the mounting facility, and can be easily mounted on the tongue.

  As the alignment mark, for example, as in the invention according to claim 9, a center line that is a virtual line segment connecting the centers of the alignment marks is formed in parallel to the surface of the lid member. Two through holes can be employed.

  Further, in the sensor device according to any one of claims 1 to 9, for example, according to the invention according to claim 10, the first and second sensor chips have a stack structure in which one is stacked on the other. By mounting on the mounting surface of the lead frame, the sensor device can be miniaturized by effectively using the space in the housing.

  Moreover, in the sensor device according to any one of claims 1 to 9, for example, according to the invention according to claim 11, both the first and second sensor chips are formed on the mounting surface of the lead frame with bare chips. By mounting in a state, the second sensor chip, which is often sealed with a ceramic package or the like, can be disposed in a bare chip state.

  Further, in the sensor device according to any one of claims 1 to 11, for example, according to the invention according to claim 12, the processing circuit portions of the first and second sensor chips are separated and shared. The circuit further comprises a circuit chip, and the processing circuit chip is mounted on the mounting surface of the lead frame together with the first and second sensor chips, whereby the processing circuit of the first sensor chip and the second sensor chip As described above, a common part can be shared by the processing circuit chip, and the sensor device can be further miniaturized.

(First embodiment)
A first embodiment of a sensor device according to the present invention will be described below with reference to FIGS.

  FIG. 1 shows the overall structure of the sensor device of the present embodiment. As shown in FIG. 1, this sensor device is roughly composed of a first sensor chip 10 having a magnetoresistive element, a second sensor chip 20 having an acceleration detecting element, a magnet 30, a cover member 40, and a lid member 50. , And a lead frame 60.

  The first sensor chip 10 has magnetoresistive element pairs 1 and 2 constituted by magnetoresistive elements MRE1 to MRE4, and differential amplification of signals detected by these magnetoresistive element pairs 1 and 2 It is integrated with a processing circuit that performs various processes such as binarization. In addition, since the aspect of the rotation detection through the magnetoresistive element pairs 1 and 2 is well-known, the detailed description is omitted.

  The second sensor chip 20 has, for example, a strain gauge type (piezoresistive type) acceleration detection element, and is integrated into an integrated circuit together with a processing circuit that performs various processing of signals detected by the acceleration detection element. And accommodated in a ceramic package. As the second sensor chip 20, a sensor having a capacitance type or piezoelectric type acceleration detection element can be used in addition to the strain gauge type. Further, since the detection mode of acceleration through these strain gauge type, capacitance type, and piezoelectric type acceleration detection elements is well known, the detailed description thereof will be omitted.

  The magnet 30 has a cylindrical shape having a hollow portion, and is disposed at the bottom of the cover member 40 formed in a bottomed cylindrical shape. The magnet 30 applies an appropriate bias magnetic field to the first sensor chip 10 accommodated in the hollow portion, and thereby, a magnetic vector generated in cooperation with the bias magnetic field when the rotor rotates. The change is sensed as a change in the resistance value of the magnetoresistive elements MRE1 to MRE4, and the rotation mode of the rotor is detected. The cover member 40 is made of a nonmagnetic material such as resin or ceramic.

  Moreover, the said cover material 50 is formed in the substantially disc shape, for example, is comprised with nonmagnetic and insulating materials, such as resin and a ceramic. The lid member 50 has a plate-like tongue portion 51 that is extended in a manner protruding inward of the cover member 40 and into which the lead frame 60 is integrally cast. The lead portion 61 is configured as a lid member structure derived from the back surface of the lid member 50 as a GND (ground) terminal T1, output terminals T2, T3, and a power supply terminal T4. The first sensor chip 10 and the second sensor chip 20 are mounted on the mounting surface of the first sensor chip 10 and the second sensor chip 20 in the tongue 51. 20 is sealed by the housing which consists of the said cover member 40 and the cover material 50, and is interrupted | blocked from the exterior. The first sensor chip 10 is mounted in a bare chip state.

  FIG. 2 shows a planar structure of the lid member structure. As shown in FIG. 2, the first sensor chip 10 is mounted on the tip of the tongue 51. The first sensor chip 10 includes a ground electrode GND, an output electrode Out, and a power supply electrode Vcc on the surface opposite to the mounting surface, and these electrodes are connected to the GND terminal T1 of the lead frame 60 via the bonding wires W. The output terminal T3 and the power supply terminal T4 are electrically connected. The second sensor chip 20 includes a ground electrode GND, an output electrode Out, and a power supply electrode Vcc on the mounting surface, and these electrodes are mounted in such a manner that they are directly connected to the lead frame 60. Are electrically connected to the GND terminal T1, the output terminal T2, and the power supply terminal T4 of the lead frame 60. The GND terminal T1 and the power supply terminal T4 are shared by the first sensor chip 10 and the second sensor chip 20.

  Moreover, the said cover material 50 is equipped with the protrusion 52 along the outer peripheral part fitted to the said cover member 40, and this protrusion 52 and the internal peripheral surface of the said cover member 40 are epoxy adhesives, for example. It is fixed with silicon adhesive.

  FIG. 3 shows a cross-sectional structure of the sensor device. As shown in FIG. 3, the lid structure is assembled integrally with the cover member 40, and the first sensor chip 10 mounted on the tip of the tongue 51 is a hollow of the magnet 30. It is housed in the department. The front end surface of the tongue 51 is fixed to the inner bottom surface of the cover member 40 with, for example, an epoxy adhesive or a silicon adhesive. Further, in the lead frame 60, the lead portion 61 is formed thicker than the other portions in order to ensure the rigidity of the lead portion 61 that is also used as a terminal. In order to secure the rigidity of the lead part 61, it is also effective to form the lead part 61 wide.

Next, a method for manufacturing the sensor device of the present embodiment will be described with reference to FIG.
As shown in FIG. 4, in manufacturing the sensor device of the present embodiment, first, the cylindrical magnet 30 is disposed on the inner bottom surface of the cover member 40 formed in a bottomed cylindrical shape. Next, the lid member structure in which the first sensor chip 10 and the second sensor chip 20 are mounted on the tongue 51 is assembled to the cover member 40. At this time, an adhesive is applied to the protrusions 52 of the lid member 50, and an adhesive is also applied to the distal end surface of the tongue 51 to assemble the lid member structure to the cover member 40. As a result, the front end surface of the tongue 51 is bonded and fixed to the inner bottom surface of the cover member 40, and the protrusion 52 of the lid member 50 is bonded and fixed to the cover member 40. Thereby, the sensor device of the present embodiment is manufactured.

According to the first embodiment described above, the effects listed below can be obtained.
(1) The first sensor chip 10 and the second sensor chip 20 are arranged in a housing formed by a cover member 40 and a lid member 50 that are hermetically sealed so as to be cut off from the external atmosphere. As a result, the first sensor chip 10 and the second sensor chip 20 are arranged in the housing and combined into one, so that the space required for the arrangement of the sensor device is a space for one sensor. As a result, the degree of freedom for mounting in a limited space can be greatly increased.

  (2) The first sensor chip 10 is mounted on the mounting surface of the lead frame 60 in a bare chip state, and the GND terminal T1 and the power supply terminal T4 of the lead frame 60 are connected to the first sensor chip 10 and the second sensor chip 10. The sensor chip 20 is shared. Thereby, since the first sensor chip 10 is mounted without being subjected to resin molding or the like, it can be mounted on the tongue 51 together with the second sensor chip 20. Further, by sharing the GND terminal T1 and the power supply terminal T4, the lead frame 60 required for mounting the first sensor chip 10 and the second sensor chip 20 can be minimized, so that the sensor device Miniaturization can be achieved.

  (3) The lid member 50 has a plate-like tongue portion 51 in which the lead frame 60 is integrally cast, and the lead portion 61 of the lead frame 60 is led out from the back surface of the lid member 50. A lid material structure was formed. For this reason, the first sensor chip 10 and the second sensor chip can be simply assembled by assembling the lid member structure on which the first sensor chip 10 and the second sensor chip 20 are mounted on the cover member 40. It becomes possible to arrange 20 in a sealed form so as to shut off 20 from the external atmosphere.

(4) Since the front end surface of the tongue 51 is bonded and fixed to the inner bottom surface of the cover member 40, the rigidity of the tongue 51 can be increased. This also suppresses the vibration of the tongue 51 on which the first sensor chip 10 and the second sensor chip 20 are mounted, so that the first sensor chip 10 and the second sensor due to vibration are suppressed. The influence on the sensing characteristics of the chip 20 is suitably suppressed.
(Second Embodiment)
Next, a second embodiment of the sensor device according to the present invention will be described with reference to FIGS. 5 and 6 and differences from the first embodiment. FIG. 5 shows the entire structure of the lid member structure of the present embodiment from the plane direction, and FIG. 6 shows the cross-sectional structure of the embodiment from the side surface direction. 5 and 6, the same elements as those shown in FIGS. 1 to 4 are denoted by the same reference numerals, and redundant description of these elements is omitted.

  The sensor device of the present embodiment also basically has a configuration according to the first embodiment shown in FIGS. However, in the present embodiment, the width of the distal end portion of the tongue portion forming the lid member structure is narrower than the proximal end portion of the tongue portion, and the lead frame and the first and An alignment mark indicating the reference position is formed on the surface on which the mounting surface of the second sensor chip is provided.

  As shown in FIG. 5, the first sensor chip 10a is mounted on the tip of the tongue 51a. The first sensor chip 10a includes a ground electrode GND, an output electrode Out, and a power supply electrode Vcc on the surface opposite to the mounting surface, and these electrodes are connected to the second sensor chip 20a via the bonding wires W1. Electrically connected.

  On the other hand, as shown in FIG. 5, the second sensor chip 20a is mounted closer to the base end side than the first sensor chip 10a of the tongue 51a. The second sensor chip 20a includes a ground electrode GND, an output electrode Out2, an output electrode Out1, and a power supply electrode Vcc on the surface opposite to the mounting surface, and these electrodes are connected to the lead frame 60 via the bonding wires W2. Are electrically connected to the GND terminal T1, the output terminal T3, the output terminal T2, and the power supply terminal T4. That is, the terminals T1 to T4 are shared by the first sensor chip 10a and the second sensor chip 20a. Incidentally, the output electrode Out1 of the second sensor chip 20a is an electrode that performs an appropriate process on the output signal of the sensor chip 10a taken from the first sensor chip 10a via the bonding wire W1 and outputs it. The output electrode Out2 of the second sensor chip 20a is an electrode that outputs an output signal of the second sensor chip 20a.

  Also, as shown in FIG. 6, the lid structure is assembled integrally with the cover member 40, and the first sensor chip 10a mounted on the tip of the tongue 51a is connected to the magnet 30a. It is accommodated in the hollow part. As shown in FIG. 6, the cover member 40 is fixed to the tongue portion lead-out surface 53 by, for example, ultrasonic welding.

  By the way, when the lead frame 60, the first sensor chip 10a, and the second sensor chip 20a are mounted on the tongue portion 51a forming the lid member structure, mounting equipment is used. These mountings require high positioning accuracy.

  On that point, the surface on which the mounting surface of the lead frame 60, the first sensor chip 10a, and the second sensor chip 20a of the tongue 51a forming the lid member structure is provided is an alignment indicating a reference position. As a mark, two through holes Ah1 and Ah2 are formed on both sides of the second sensor chip 20a. Specifically, as shown in FIG. 5, a center line “C1-C2” that is a virtual line segment that connects the centers C1 and C2 of the through holes Ah1 and Ah2 to each other is formed on the surface of the lid member 50. They are formed in parallel to each other. Thereby, by using these through holes Ah1 and Ah2 as a reference, the lead frame and the first and second sensor chips 10a, 20a can be positioned with high accuracy on the die mount equipment, It becomes possible to easily mount the tongue portion 51a.

  Further, the inner inner wall or tip of the magnet 30a applies a stronger bias magnetic field to the first sensor chip 10a, more precisely, the magnetoresistive elements MRE1 to MRE4 (not shown) as compared to other portions. It is a part that can be done. Therefore, in order to apply a stronger bias magnetic field to the first sensor chip 10a, that is, to increase the resistance value change of the magnetoresistive elements MRE1 to MRE4 (not shown), the first sensor chip 10a is attached to the magnet. It is desirable to be closer to the side inner wall or the tip of 30a.

  In this respect, the tip end portion of the tongue portion 51a is formed so that the width Wd2 thereof is narrower than the width Wd1 of the base end portion of the tongue portion 51a as shown in FIG. This makes it possible to reduce the distance between the first sensor chip 10a and the side inner wall or tip of the magnet 30a without increasing the chip size of the first sensor chip 10a. That is, it is possible to increase the resistance value change of the magnetoresistive elements MRE1 to MRE4 while suppressing a decrease in the yield of the first sensor chip 10a, and thus improve the detection accuracy related to the rotation mode of the rotor (not shown). It becomes possible.

  FIG. 7A schematically shows the arrangement of the first sensor chip 10a and the magnet 30a from the front direction in the sensor device configured as described above. FIG. 7B schematically illustrates the arrangement of the first sensor chip 110 and the magnet 130 from the front direction in a conventional sensor device in which the first sensor chip 10a is resin-molded with the mold resin Md. It is shown as an example.

  As shown in FIG. 7A, in the present embodiment, since the first sensor chip 10a is mounted on the tongue 51a in a bare chip state, the first sensor chip 10a and the magnet The side inner wall portion 30a is spaced apart by a distance “Wp”. On the other hand, as shown in FIG. 7B, in the conventional sensor device, since the first sensor chip 110 is mounted on the lead frame 160 by molding resin Md, the first sensor chip 110 is mounted. The chip 110 and the side inner wall portion of the magnet 130 are disposed apart from each other by a distance “Wh”.

  Specifically, as shown in FIG. 7B, in the conventional sensor device, the distance “Wh” between the first sensor chip 110 and the inner side wall portion of the magnet 130 is the case where the mold resin Md is the thinnest. In the sensor device according to the present embodiment, as shown in FIG. 7A, the distance between the first sensor chip 10a and the inner side wall portion of the magnet 30a. The inventors have confirmed that “Wp” is “0.20 ± 0.05 [mm]”. That is, as is clear from the comparison between FIGS. 7A and 7B, according to the sensor device of the present embodiment, the first sensor chip 10a is not covered with the mold resin. The first sensor chip 10a can be brought closer to the side inner wall portion of the magnet 30a than the first sensor device.

  Further, FIG. 8A shows the relationship between the distance from the inner wall of the magnet 130 to the first sensor chip 110 (more precisely, the internal magnetoresistive elements MRE1 to MRE4) and the magnetic contact angle. FIG. 8B shows the relationship between the distance from the tip of 30a to the first sensor chip 10a (to be precise, the internal magnetoresistive elements MRE1 to MRE4) and the magnetic contact angle.

  As shown in FIG. 8A, the point “B1” indicates a point corresponding to the distance “Wh” between the first sensor chip 110 and the side inner wall portion of the magnet 130 in the conventional sensor device. The magnetic contact angle at this time is approximately “1.8 [degrees]”. On the other hand, in FIG. 8 (a), the point “A1” corresponds to the distance “Wp” between the first sensor chip 10a and the inner side wall portion of the magnet 30a in the present embodiment. The magnetic contact angle at the time is approximately “2.9 [degree]”.

  As shown in FIG. 8B, the point “B2” indicates the distance corresponding to the distance between the first sensor chip 110 and the tip of the magnet 130 in the conventional sensor device. The touch angle is approximately “1.2 [degree]”. On the other hand, in FIG. 8B, the point “A2” indicates the distance corresponding to the distance between the first sensor chip 10a and the tip of the magnet 30a in the present embodiment, and the magnetic contact angle at this time Is approximately “2.0 [degrees]”.

  In this way, by bringing the first sensor chip 10a closer to the side inner wall or the tip of the magnet 30a, a stronger bias magnetic field can be applied from the magnet 30a to the first sensor chip 10a. As a result, the touch angle of the magnetic vector detected by the magnetoresistive elements MRE1 to MRE4 also increases.

According to the second embodiment described above, in addition to the effects according to the above (1) to (4) of the first embodiment, the effects listed below are newly obtained. .
(5) The width Wd2 of the distal end portion of the tongue portion 51a forming the lid member structure is formed to be narrower than the width Wd1 of the proximal end portion of the tongue portion 51a. This makes it possible to reduce the distance between the first sensor chip 10a and the side inner wall or tip of the magnet 30a without increasing the chip size of the first sensor chip 10a. That is, it is possible to increase the resistance value change of the magnetoresistive elements MRE1 to MRE4 while suppressing a decrease in the yield of the first sensor chip 10a, thereby improving the detection accuracy relating to the rotation mode of the rotor (not shown). It becomes possible.

  (6) As an alignment mark indicating a reference position on the surface on which the lead frame 60 and the mounting surfaces of the first and second sensor chips 10a and 20a of the tongue portion 51a forming the lid structure are provided. Two through holes Ah1 and Ah2 are formed on both sides of the second sensor chip 20a. Accordingly, the lead frame 60 and the first and second sensor chips 10a and 20a are easily mounted on the tongue 51a with high accuracy by using the two through holes Ah1 and Ah2 as alignment marks as a reference. Will be able to.

The second embodiment can be implemented with the following modifications.
In the second embodiment, a reference surface is provided on the surface on which the mounting surface of the lead frame 60 and the first and second sensor chips 10a and 20a of the tongue portion 51a forming the lid structure is provided. Two alignment holes Ah1 and Ah2 are formed on both sides of the second sensor chip 20a as alignment marks indicating positions. The positions and number of these through holes are arbitrary and may be formed on the mounting surface of the tongue 51a.

-It is not necessary to use a through-hole for such an alignment mark. In short, when the lead frame 60 and the first and second sensor chips 10a and 20a are mounted, a reference for positioning may be formed on the tongue 51a.
(Other embodiments)
Other elements that can be changed in common with the above embodiments are as follows.

  In the above embodiments, the electrodes of the first sensor chip 10, 10a and the second sensor chips 20, 20a and the terminals T1 to T4 of the lead frame 60 are shown in FIGS. Although it was decided to be electrically connected in a form, the connection of these in consideration of the electrode structure of the first sensor chip 10, 10a and the second sensor chip 20, 20a, the handling of the terminals T1 to T4, etc. The aspect may be changed as appropriate. For example, as shown in FIG. 9A, the output of the first sensor chip 10 (10a) according to the electrode structure of the first sensor chip 10 (10a) or the second sensor chip 20 (20a). You may replace the position of terminal T3 and electric power feeding terminal T4. Further, as shown in FIG. 9B, the lead frame 60 corresponding to the GND terminal T1 and the power supply terminal T4 is extended without passing through the inside of the second sensor chip 20 (20a). Also good.

  In each of the above embodiments, the first sensor chip 10, 10a and the second sensor chip 20, 20a perform various processes such as differential amplification and binarization together with the magnetoresistive element and the acceleration detection element. The processing circuit is shown as an integrated circuit. Instead of this, it is configured to further include a processing circuit chip in which such processing circuit portions are separated and shared, and this processing circuit chip is connected to the first sensor chip 10, 10a and the second sensor chip 20, 20a. You may mount on the tongue parts 51 and 51a. As a result, the processing circuit chip can share a common portion as the processing circuit of the first sensor chip 10, 10 a and the second sensor chip 20, 20 a, thereby further reducing the size of the sensor device. It becomes possible to plan.

  In each of the above embodiments, as shown in FIG. 3, the protrusion 52 and the inner peripheral surface of the cover member 40 are fixed by, for example, an epoxy adhesive or a silicon adhesive, or in FIG. As shown, the tongue lead-out surface 53 and the cover member 40 are fixed by, for example, sensor welding, but the fixing mode is not limited to this and is arbitrary.

  In each of the above embodiments, when mounting the first sensor chip 10, 10 a and the second sensor chip 20, 20 a, the first sensor chip 10, 10 a is placed on the distal end side of the tongue portions 51, 51 a. Although the mounting is performed, the second sensor chips 20 and 20a may be mounted on the distal ends of the tongue portions 51 and 51a. In addition, as shown in FIG. 12, the first sensor chip 10 (10a) and the second sensor chip 20 (20a) may be mounted with a stack structure in which one is stacked on the other. In this case, the sensor device can be downsized by effectively using the space in the cover member 40.

  In each of the above embodiments, the first sensor chip 10 or 10a is mounted in a bare chip state, but a part of the outer peripheral surface thereof is exposed without being covered with the mold resin (so-called straddle mold) ) And mounted on the mounting surface of the lead frame.

  In each of the above embodiments, the first sensor chip 10, 10a is mounted in a bare chip state, but the second sensor chip 20, 20a is also arranged in a bare chip state. Also good. The second sensor chips 20 and 20a are normally housed in a ceramic package in order to cut off the chip having the acceleration detection element and the processing circuit chip from the external atmosphere, but the cover member 40 and the lid member 50 are used. In the above configuration that is cut off from the external atmosphere, the second sensor chips 20 and 20a can be mounted in a bare chip state without any problem.

  In each of the above embodiments, the present invention is applied to the sensor device in which the first sensor chip 10 or 10a is accommodated in the hollow portion of the magnet 30 or 30a. As a corresponding figure, as shown in FIG. 10, instead of the magnet 30 (30a), the present invention is applied to a sensor device in which a rectangular parallelepiped magnet 70 is disposed on the back surface of the lead frame exposed surface of the tongue 51 (51a). The invention may be applied. When this structure is adopted, the same effect as that of the above embodiment can be obtained, and the magnet 70 can be downsized as compared with the magnet 30 (30a) of the above embodiment. 50 can be reduced in size, and as a result, the sensor device can be reduced in size.

  The present invention can also be applied to a sensor device in which the magnet 30 (30a) is externally fitted to the cover member 40 as shown in FIG. 11 as a diagram corresponding to FIG. 3 and FIG. When this structure is employed, although the magnet 30 (30a) is attached to the outside of the cover member 40, the same effects as those of the above embodiments can be obtained.

  In each of the above embodiments, the case where the lead portion 61 of the lead frame 60 is led out from the back surface of the lid member 50 has been described, but the lead portion 61 may be led out from the cover member 40, for example.

  In each of the above embodiments, the housing that shuts off the first sensor chip 10, 10 a and the second sensor chip 20, 20 a from the external atmosphere is configured by the cover member 40 and the lid member 50. For example, you may comprise the said housing with two bottomed cylindrical cover members. In short, the first sensor chip 10, 10a and the second sensor chip 20, 20a arranged in a bare chip state (including the straddle mold state) can be sealed to shut off from the external atmosphere. If it is a housing, you may employ | adopt what consists of another shape as an element which comprises the housing.

The perspective view which shows the whole structure about 1st Embodiment of the sensor apparatus concerning this invention. The top view which shows the whole structure about a lid | cover material structure. Side surface sectional drawing which shows the cross-sectional structure about the sensor apparatus of the embodiment. The perspective view which decomposes | disassembles and shows each element which comprises the sensor apparatus of the embodiment. The top view which shows the whole structure of the cover material structure about 2nd Embodiment of the sensor apparatus concerning this invention. Side surface sectional drawing which shows the cross-sectional structure about the sensor apparatus of the embodiment. (A) is sectional drawing which shows the arrangement | positioning aspect of a 1st sensor chip and a magnet from a front direction about the sensor apparatus of the embodiment. (B) is sectional drawing which shows typically the arrangement | positioning aspect of the 1st sensor chip and a magnet from the front direction about the conventional sensor apparatus by which the 1st sensor chip was resin-molded with mold resin. About the same embodiment, (a) is a graph which shows the relationship between the distance from a magnet side surface, and a magnetic deflection angle. (B) is a graph showing the relationship between the distance from the magnet tip and the magnetic deflection angle. (A) And (b) is a top view which shows the lid | cover material structure employ | adopted as the modification of said each embodiment. Sectional drawing shown as a figure corresponding to FIG.3 and FIG.6 about the modification of said each embodiment. Sectional drawing shown as a figure corresponding to FIG.3 and FIG.6 about the modification of said each embodiment. Sectional drawing shown as a figure corresponding to FIG.3 and FIG.6 about the modification of said each embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,2 ... Magnetoresistive element pair 10, 10, 10a, 110 ... 1st sensor chip, 20, 20a ... 2nd sensor chip, 30, 30a, 130 ... Magnet, 40 ... Cover member, 50 ... Cover material, 51 51a ... tongue, 52 ... protrusion, 53 ... tongue lead-out surface, 60, 160 ... lead frame, 61 ... lead, 70 ... magnet, T1 ... GND (ground) terminal, T2 ... output terminal, T3 ... output Terminal, T4: Feed terminal, MRE1 to MRE4: Magnetoresistive element. W, W1, W2: Bonding wires.

Claims (12)

A first sensor chip having a magnetoresistive element; a second sensor chip having an acceleration sensing element; a lead frame on which the first and second sensor chips are mounted; and the magnetism of the first sensor chip. And a magnet for applying a bias magnetic field to the resistance element, and at least the first and second sensor chips are disposed in a sealed housing for shielding from an external atmosphere. Acceleration acting on the housing by detecting a rotation mode of the rotor by detecting a change in the magnetic vector generated in cooperation with the bias magnetic field as a change in the resistance value of the magnetoresistive element when the rotor rotates in the vicinity. Is detected together through the acceleration sensing element provided in the second sensor chip. 2. The at least first sensor chip is mounted on the mounting surface of the lead frame in a bare chip state, and a lead frame portion used for power feeding is shared by the first and second sensor chips. The sensor device according to 1. The housing includes a bottomed cylindrical cover member made of a non-magnetic material, and a lid member made of an insulating material that closes the opening end of the cover member. The lead member has a plate-like tongue portion that is extended in an inward projecting manner of the cover member and in which mounting surfaces of the lead frame and the first and second sensor chips are integrally cast, and the lead A lead part also serving as a terminal of the frame is formed as a structure derived from the back surface of the lid member, and the magnet is formed in a cylindrical shape having a hollow part and disposed on the inner bottom surface of the housing. And at least the first sensor chip is disposed in the housing so as to be accommodated in the hollow portion of the magnet in a state of being mounted on the distal end side of the tongue portion forming the lid member structure. Claim 1 or 2 The sensor device described. The housing includes a bottomed cylindrical cover member made of a non-magnetic material, and a lid member made of an insulating material that closes the opening end of the cover member. The lead member has a plate-like tongue portion that is extended in an inward projecting manner of the cover member and in which mounting surfaces of the lead frame and the first and second sensor chips are integrally cast, and the lead A lead portion also serving as a terminal of the frame is formed as a structure derived from the back surface of the lid member, and the magnet is formed of the lead frame of the tongue portion and the first portion forming the lid member structure. The first sensor chip is mounted on the back surface of the surface on which the mounting surface of the sensor chip is provided, and the first and second sensor chips are mounted on the tongue portion forming the lid material structure in the housing. It is arrange | positioned by Claim 1. Or the sensor apparatus of 2. The housing includes a bottomed cylindrical cover member made of a non-magnetic material, and a lid member made of an insulating material that closes the opening end of the cover member. The lead member has a plate-like tongue portion that is extended in an inward projecting manner of the cover member and in which mounting surfaces of the lead frame and the first and second sensor chips are integrally cast, and the lead The lead part also serving as a terminal of the frame is formed as a structure led out from the back surface of the lid member, and the magnet is formed in a cylindrical shape having a hollow part and is externally fitted to the housing. The sensor device according to claim 1, wherein the first sensor chip is disposed in the housing in a state where the first sensor chip is mounted on a distal end side of the tongue portion forming the lid member structure. The sensor device according to any one of claims 3 to 5, wherein a tip end surface of the tongue portion forming the lid member structure is bonded and fixed to an inner bottom surface of the cover member. The sensor device according to any one of claims 3 to 6, wherein a distal end portion of the tongue portion forming the lid structure is formed to have a width narrower than a proximal end portion of the tongue portion. The alignment mark which shows a reference position is formed in the surface in which the mounting surface of the said lead frame of the said tongue part which forms the said cover material structure, and the said 1st and 2nd sensor chip is provided. The sensor device according to claim 7. The sensor according to claim 8, wherein the alignment mark is two through-holes formed such that a center line that is a virtual line segment connecting the centers of the alignment marks is parallel to the surface of the lid member. apparatus. The sensor device according to any one of claims 1 to 9, wherein the first and second sensor chips are mounted on a mounting surface of the lead frame with a stack structure in which one is stacked on the other. The sensor device according to any one of claims 1 to 9, wherein both the first and second sensor chips are mounted in a bare chip state on a mounting surface of the lead frame. A processing circuit chip in which processing circuit portions of the first and second sensor chips are separated and shared is further provided, and the processing circuit chip is mounted on the mounting surface of the lead frame together with the first and second sensor chips. The sensor device according to any one of claims 1 to 11.

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