JP2004294295A - Sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the secular change of adhesive stress of a circuit chip provided with a temperature sensor device. <P>SOLUTION: A main body 11 of the sensor is provided with a pressure sensor 13 and a circuit chip 14 provided with a temperature sensor circuit for temperature compensating the signal outputted from the pressure sensor 13. The circuit chip 14 is adhered to the main body 11 with an adhesive agent 16 with balls 15 which are interposed between the main body 11 and circuit chip 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a sensing unit that outputs an electric signal according to a detected physical quantity and a circuit chip that includes a temperature sensor that detects a temperature and adjusts the output electric signal based on a detected temperature value are attached to a main body. Related to a sensor device.
[0002]
[Prior art]
Conventionally, as this type of sensor device, there is one having a configuration shown in FIG. 2, a pressure sensor 2 as a sensing unit is attached to a main body 1 with an adhesive, and a circuit chip 3 is attached with an adhesive. Further, a pressure inlet 1a is formed in the main body 1 and is connected to a pressure measuring object via a pressure introducing hose or the like (not shown) so as to introduce a pressure as a physical quantity to be detected of the pressure measuring object. It has become. The pressure sensor 2 is electrically connected to a circuit chip 3 via a bonding wire 4, and the circuit chip 3 is electrically connected to a connector pin 6 via a bonding wire 5.
[0003]
The pressure sensor 2 outputs an electric signal corresponding to the introduced pressure, and is composed of, for example, a Si diaphragm type pressure sensor. The circuit chip 3 has a built-in amplifier circuit for amplifying the electric signal and a temperature sensor. The temperature sensor is constituted by a resistance bridge of two types of semiconductor resistance elements (elements having piezoresistance effects in opposite directions) having different change characteristics, and performs temperature compensation for sensitivity and offset in an analog manner. A pressure detection signal is output from the circuit chip 3 having the temperature sensor.
[0004]
Patent Document 1 discloses an electrical configuration.
[0005]
[Patent Document 1]
Japanese Patent Application No. 11-64135 [0006]
[Problems to be solved by the invention]
By the way, since the temperature sensor in the circuit chip 3 is composed of a semiconductor resistance element, when the mechanical stress applied to the circuit chip 3 changes, the resistance characteristic also changes greatly. It is important not to cause.
[0007]
However, since the circuit chip 3 provided with the temperature sensor is almost directly pressed and fixed to the main body 1 with a thin layer of adhesive to some extent, the stress of the circuit chip 3 is relieved with time, There is a problem that the initial temperature compensation adjustment value shifts and the sensor output characteristics shift.
[0008]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circuit having a built-in temperature sensor for temperature-compensating the output of a sensing unit, and to reduce the change over time of the fixing stress of the circuit chip. It is another object of the present invention to provide a sensor device capable of reducing the influence on temperature compensation and preventing the output characteristics of the sensor from shifting with time.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, the circuit chip is bonded to the main body with the adhesive together with the mass member in a form in which a plurality of mass members are interposed between the main body and the circuit chip of the temperature sensor. The time-dependent change in stress due to adhesion to the chip is small, and the influence on temperature compensation is reduced. As a result, the sensor output characteristics do not shift over time.
[0010]
In this case, as in the second aspect of the present invention, the plurality of massive members may be formed to have substantially the same spherical shape. In this case, the thickness of the adhesive between the main body and the circuit chip is kept uniform. Therefore, the bonding strength to the circuit chip is stabilized in a relatively loose state.
[0011]
Further, the mass member may be made of resin as in the third aspect of the invention. In this case, the mass member can be easily manufactured and the cost can be reduced.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a pressure sensor device will be described with reference to FIG. The main body 11 is made of, for example, resin, and has a concave portion 11a formed on the upper right side. A pressure inlet 11b is formed so as to communicate with the bottom of the recess 11a. A pressure sensor 13 serving as a sensing unit is attached to the recess 11a via a cylindrical glass pedestal 12. The pedestal 12 is adhered to the recess 11a by, for example, a silicone rubber-based adhesive 21. The pressure to be measured is introduced into the pressure inlet 11b, and is output by the pressure sensor 13 as an electric signal corresponding to the pressure.
[0013]
The circuit chip 14 includes a temperature sensor and an amplifier circuit. The temperature sensor is configured by a resistance bridge of two types of semiconductor resistance elements (elements having piezoresistance effects in opposite directions) having different change characteristics. The temperature compensation for the temperature and the offset is performed in an analog manner, and a pressure detection signal is output from the circuit chip 14 having the temperature sensor.
[0014]
The circuit chip 14 is mounted on the flat upper surface 11c of the main body 11 that is continuous with the recess 11a. That is, the circuit chip 14 has a plurality of lumps 15 of substantially the same shape as a block-like member interposed between the upper surface 11c of the main body 11 and the circuit chip 14, and these spheres 15 are adhered together with the adhesive 16. . The adhesive 16 is preferably relatively soft, for example, a silicone rubber-based adhesive. The sphere 15 is made of resin.
[0015]
A connector pin 17 is provided on the upper left side of the main body 11 by insert molding. The pressure sensor 13 is electrically connected to a circuit chip 14 via a bonding wire 18, and the circuit chip 14 is electrically connected to a connector pin 17 via a bonding wire 19. The pressure detection signal is transmitted to an external circuit via the connector pin 17. The main body 11 is covered by a cover case 20.
[0016]
According to the present embodiment, the circuit chip 14 is attached to the main body 11 together with the sphere 15 in a form in which a plurality of spheres 15 are interposed between the main body 11 and the circuit chip 14 of the temperature sensor. Since the bonding is carried out by the step 16, the change with time of the stress due to the bonding to the circuit chip 14 is small, and the influence on the temperature compensation is reduced. As a result, the sensor output characteristics do not shift over time.
[0017]
Further, according to this embodiment, since the plurality of massive members are spherical bodies 15 having substantially the same shape, the thickness of the adhesive 16 between the main body 11 and the circuit chip 14 can be kept uniform, and the circuit chip 14 is stabilized in a relatively loose state. Furthermore, since the sphere 15 is made of resin, the production is easy and the cost can be reduced. Furthermore, since the adhesive 16 is a soft adhesive, the stress on the circuit chip 14 is further reduced.
[0018]
The present invention is not limited to the pressure sensor device, and can be widely applied to all sensor devices including a circuit chip having a built-in temperature sensor for temperature-compensating an electric signal output from a sensing unit. Further, the mass member may be made of hard rubber or soft rubber, and the shape may be appropriately changed.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an entire pressure sensor device showing one embodiment of the present invention. FIG. 2 is a longitudinal sectional view of an entire pressure sensor device showing a conventional example.
Reference numeral 11 denotes a main body, 13 denotes a pressure sensor (sensing unit), 14 denotes a circuit chip, 15 denotes a sphere (lumpy member), and 16 denotes an adhesive.

Claims (3)

A sensor device in which a sensing unit that outputs an electric signal according to a physical quantity to be detected and a circuit chip having a built-in temperature sensor circuit that performs temperature compensation on the output electric signal are attached to a main body,
A sensor device wherein the circuit chip is adhered to the main body together with the mass member with an adhesive in a form in which a plurality of mass members are interposed between the main body and the circuit chip. 2. The sensor device according to claim 1, wherein the plurality of massive members have substantially the same spherical shape. The sensor device according to claim 1, wherein the massive member is made of resin.

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