JP2863281B2 - Contact pressure sensor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse wave sensor used for detecting a contact pressure between an object generating a measured pressure and being pressed by the object. is there.

2. Description of the Related Art There has been proposed a contact pressure sensor for detecting a contact pressure between an object that generates a measured pressure and a contact with the object. For example, a pulse wave sensor that is used when non-invasively detecting a pressure pulse wave generated in an artery immediately below the skin of a living body when pressing directly above the artery from above the skin is the same. Japanese Patent Application No. Hei 1-1151106 and Japanese Patent Application No.
No. 41050. Since the pressure fluctuation wave periodically generated in the artery of the living body, that is, the pressure pulse wave, reflects not only the blood pressure value but also the operation state of the circulatory organ, it is used for measuring the blood pressure value or diagnosing the circulatory organ. Since it is desired to non-invasively detect a pressure pulse wave in a living artery, the above-described contact pressure sensor is used. In a contact pressure sensor of this type, a semiconductor chip, which is usually provided in a housing mounted on a living body and has a pressure detecting element disposed on a front surface thereof, and a spacer member for supporting the semiconductor chip from the back surface, A substrate on which the spacer member is fixed, and the surface of the semiconductor chip is pressed toward an artery existing under the epidermis of the living body, so that a pressure pulse wave, which is a pressure oscillation in the artery, is detected. I have.

Problems to be Solved by the Invention By the way, in the conventional contact pressure sensor as described above, a plurality of foil-like wirings supported by a flexible sheet, that is, a flexible flat cable (FFC) are provided between the semiconductor chip and the substrate. Connected. In this case, the bumps arranged on the surface of the semiconductor chip and the flexible flat cable of the predetermined connection terminal on the substrate are in a state along the oblique line connecting the bump and the connection terminal. However, if a pressure reaction force from the skin acts on the flexible flat cable during the detection of the pressure pulse wave, or if the substrate warps due to a temperature change or the flexible flat cable itself contracts, one end of the flexible flat cable is connected. In this case, stress is directly transmitted to the semiconductor chip and strain is generated in the semiconductor chip, and the pressure detection becomes inaccurate and the accuracy is reduced.

The present invention has been made in view of the above circumstances, and has as its object the purpose of a pulse wave in which measurement accuracy is not affected even if a pressing reaction force from the skin is applied or temperature changes. It is to provide a sensor.

Means for Solving the Problems The gist of the present invention for achieving the object is to provide a semiconductor chip having a pressure detecting element disposed on a front surface thereof, a spacer member for supporting the semiconductor chip from a back surface, A substrate to which a spacer member is fixed, a contact pressure sensor for detecting a contact pressure when the surface of the semiconductor chip is pressed toward an object to generate a measured pressure, provided on the surface of the semiconductor chip. The connection terminals and the substrate are connected by using a flexible flat cable rising from the substrate along the side wall surface of the spacer member.

In this way, since the flexible flat cable is disposed in a state of rising from the substrate along the side wall surface of the spacer member, the reaction force from the skin acts on the flexible flat cable. Is almost completely eliminated. In addition, even if the flexible flat cable itself contracts due to the temperature change, the flexible flat cable does not follow the diagonal line indicating the diagonal shortest distance connecting the bump and the connection terminal, and transmits the tension. Since the state is not possible, no stress is transmitted to the semiconductor chip to which one end of the flexible flat cable is connected. Therefore, even if a pressing reaction force from the skin is applied or the temperature changes, the semiconductor chip is prevented from being distorted, so that the measurement accuracy is not affected and the pressure pulse wave is accurately measured. It is done.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

2 and 3 are views showing an example of a pulse wave detecting probe to which the present invention is applied, and reference numeral 10 denotes a housing. The housing 10 has a container shape as a whole, and includes a first housing 12 that opens on a wrist 34
, And a second housing 16 rotatably connected to the first housing 12. In the first housing 12, a casing 18 having a container shape and opening on the side of the wrist 34 is provided with a pair of arm portions 2 integrally provided therewith.
In FIGS. 2 and 3, a feed screw and a guide rod (not shown) are provided so as to be movable in the left-right direction in FIGS. Although not shown, a reduction gear unit operatively connected to an end of the feed screw located on the second housing 16 side is provided in the first housing 12, and the reduction gear unit is a second reduction gear unit. It is operatively connected to an output shaft of an electric motor (not shown) provided in the two housing 16 via a flexible coupling (not shown). Thereby, regardless of the rotation angle between the first housing 12 and the second housing 16, the driving force of the electric motor is transmitted to the feed screw via the reduction gear unit.

A diaphragm 24 is provided in the casing 18, thereby forming a pressure chamber (not shown) on the bottom side in the casing 18. On the surface of the diaphragm 24 opposite to the pressure chamber side, a pulse wave sensor 30 in which a plurality of pressure-sensitive elements 28 are arranged on a pressing surface 26 along the moving direction of the casing 18 is fixed, for example. The sensor 30 is configured to protrude from the casing 18 and the first housing 12 according to the pressure in the pressure chamber.

A band 32 is attached to the first housing 12 at one end. The housing 10 is disposed on, for example, the surface of a wrist 34, and the other end of the band 32 around which the wrist 34 is wound is a fastener 36. The housing 10 is mounted on the surface of the wrist 34 by engaging with the outer surface of the bottom of the first housing 12 via the. At this time, the pulse wave sensor 30
Is arranged in a direction substantially perpendicular to the radial artery 35 immediately below the skin of the wrist 34. Then, the control device (not shown) adjusts the pressure in the pressure chamber via a pressure regulator (not shown), drives the electric motor, positions the pulse wave sensor 30 on the artery, and adjusts the optimal pressure-sensitive element. After the pressing force is determined, a pulse wave is detected based on the pulse wave signal output from the optimum pressure-sensitive element at the optimum pressing force. A pair of elongate sponges 38, 40 are fixed to the open end surface of the first housing 12, so that the first housing 12 can be brought into contact with the surface of the wrist 34 at the sponges 38, 40. Has become. Double-sided adhesive sheets 42 and 44 are fixed to the contact surfaces of the sponges 38 and 40 with the wrist 34, respectively.
As a result, the first housing 12 becomes a double-sided adhesive sheet 42,44.
Is adhered to the surface of the wrist 34 based on the adhesive force of the wrist 34.

As shown in detail in FIG. 4, the pulse wave sensor 30 comprises a plastic sensor head case 50 fixed to the center of the diaphragm 24, a circuit film 52 fixed on one surface, and an adhesive layer 54 on the other surface. A ceramic plate member fixed in the central recess of the sensor head case 50 through
56, a rectangular parallelepiped spacer 58 fixed to the center of the plate member 56, and a sensor chip adhered to the spacer 58
60, and a metal protection plate 62 adhered to the sensor head case 50 for protecting the circuit film 52 and its connection part. The spacer 58 is made of a material whose surface is at least insulated so that it can be treated as an electrical insulator, for example, plastic or alumite-treated aluminum. The plate member 56 to which the circuit film 52 is fixed is a relay circuit for electrical connection from the sensor chip 60 to the external measuring device main body, and if necessary, an active element such as a multiplexer, a preamplifier, and a regulator is provided. At the same time, it also functions as a member for mechanically supporting the sensor chip 60, and corresponds to the substrate in the claims.

As shown in the perspective view of FIG. 5, the sensor chip 60 has a relatively rigid backup plate 64 made of glass or the like.
And a semiconductor chip 66 made of a silicon single crystal plate or the like adhered to one surface of the backup plate 64. The backup plate 64, which also functions as a spacer, has two unillustrated two lines for guiding the atmospheric pressure to the back surface (non-pressing side surface) of the semiconductor chip 66 through the center hole (not shown) of the spacer 58 and the plate member 56. Are provided. The semiconductor chip 66 has a thickness of about 300 microns, and a thin recessed part 68 having a thickness of several to several tens of microns is formed in a longitudinal shape by forming a longitudinal concave portion (not shown) on the back surface thereof. ing. As described in, for example, the specification and the drawings of Japanese Patent Application Laid-Open No. 2-2293 filed by the present applicant, a well-known semiconductor manufacturing method such as diffusion or implantation of impurities is used for the thin portion 68. A plurality of pressure-sensitive elements 70 for detecting contact pressure are arranged at predetermined intervals along one direction. Pulse wave sensor 30
The pressure-sensitive elements 70 are positioned directly above the artery 35 and are pressed against the skin of the living body in a posture in which their arrangement direction is orthogonal to the artery 35. Electrical signal corresponding to the distortion applied to the
A pulse wave signal representing the pressure pulse wave, which is a pressure fluctuation acting on the pressure pulse wave, is output.

As shown in more detail in FIG.
Terminals (bumps) 76 and plate members 56 provided on the surface of
The plurality of terminals 78 of the circuit film 52 provided on one surface have flexibility in which a large number of conductors 80 formed at predetermined intervals from copper foil are supported by a resin film 82 such as polyimide. So-called flexible flat cable 84 with
Connected by In the flexible flat cable 84, not only the resin film 82 is removed at both ends to expose the conductor 80, but also at the intermediate portion to enhance the bendability. The flexible flat cable 84 is bent at a substantially right angle at an intermediate portion, and one of the flexible flat cables 84 is along the surface of the plate member 56 and the other is along the side wall surface of the spacer 58 with the bent portion as a boundary. The two ends are soldered to the terminals 76 of the semiconductor chip 66 and the terminals 78 of the circuit film 52, respectively. That is, the flexible flat cable 84 extends along the side wall surface of the spacer 58,
It is arranged vertically standing from 56.

Around the spacer 58 and on the upper surface of the plate member 56, an isolation seal 86 is provided in a state of overlapping with a part of the flexible flat cable 84,
A part of the ground terminal of the terminal 78 and the protection plate 62 are connected by a conductive rubber piece 88. Further, the upper surface of the sensor chip 60 is thinly coated with silicon rubber 90, and the periphery of the spacer 58 is filled with silicon rubber 90, and an inclined surface following the surface of the protection plate 62 around the sensor chip 60. Are formed. A thin black conductive rubber layer 92 overlying the silicon rubber layer on the upper surface of the sensor chip 60
Are formed. Further, a resin isolation seal layer 94 for insulation is applied to the surface of the protection plate 62. 96 is the sensor chip 60 and spacer
Reference numeral 98 denotes an adhesive layer between the protective plate 62 and the sensor head case 50. An ultraviolet curable resin is suitably used for the adhesive layer.

In the pulse wave sensor 30 configured as described above, since the flexible flat cable is disposed in a state of rising vertically from the plate member 56 along the side wall surface of the spacer 58, the pressing reaction force from the skin is flexible. The action on the flat cable 84 is almost eliminated. In addition, warpage of the plate member 56 due to temperature change and flexible flat cable
Even if the 84 itself contracts, the flexible flat cable 84 does not follow the diagonal line indicating the diagonal shortest distance connecting the bump 76 and the connection terminal 78, and it is in a state where tension cannot be transmitted. Flexible flat cable 84
Is not transmitted to the semiconductor chip 66 to which one end of the semiconductor chip 66 is connected. Therefore, even if a pressing reaction force from the skin is applied or temperature changes, the semiconductor chip 66
Since the occurrence of distortion is prevented, the measurement accuracy is not affected, and the pressure pulse wave is accurately measured.

Further, according to this embodiment, since the semiconductor chip 66 is covered with the black conductive rubber layer 92 functioning as a light shielding layer, the pressure-sensitive element 70 provided on the thin portion 68 of the semiconductor chip 66 is provided.
And the measurement accuracy is greatly improved, and the black conductive rubber layer 92 suppresses the effect of static electricity.

Further, according to the present embodiment, since the protection plate 62 is grounded, a guard ring function is provided, so that the influence of high frequency noise due to, for example, an electric scalpel can be suitably suppressed.

As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.

For example, in the above-described embodiment, the semiconductor chip 66 is provided with the plurality of pressure-sensitive elements 70, but may be one.

Also, the flexible flat cable of the above-described embodiment is used.
Although the portion 84 was provided with a portion parallel to the plate member 56, it may be directly raised from the circuit film 52,
In addition, even if it is started up almost vertically with a slight inclination, a certain effect can be obtained.

In the above-described embodiment, the circuit film 52 is provided on one surface of the plate member 56.
The substrate is formed by fixing the substrate, but a ceramic plate or the like having a thick-film conductor wired on one surface may be used.

Further, in the above-described embodiment, the pressure-sensitive elements 70 are provided at predetermined intervals in the elongated thin portion 68, but the pressure-sensitive elements may be provided in the thin portions of the individual concave portions. is there.

Although a silicon single crystal plate is used for the semiconductor chip 66 described above, a single crystal plate of a compound semiconductor such as gallium-arsenic may be used.

Further, in the above-described embodiment, the pressure-sensitive element 70 is configured to include the semiconductor strain resistance element, but may be configured by a pressure-sensitive diode, a pressure-sensitive transistor, or the like.

Further, the above-described embodiment has been described with respect to the pulse wave detection probe of a type attached to the wrist 34 for detecting the pulse wave of the radial artery 35, but is applied to the carotid artery and the dorsal foot artery. It may be something.

The above is merely an example of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram showing the pulse wave sensor of FIG. 4 in a further enlarged manner. FIG. 2 is a view showing a mounted state of a pulse wave detecting probe including the pulse wave sensor of the present invention. FIG. 3 is a view of the pulse wave detection probe of FIG. 2 viewed from the wrist side. FIG. 4 is a cross-sectional view illustrating the configuration of a pulse wave sensor provided in the pulse wave detection probe shown in FIGS. 2 and 3. Fifth
The figure is a perspective view illustrating the configuration of the sensor chip of FIG. 30: pulse wave sensor (contact pressure sensor) 35: radial artery 52: circuit membrane (substrate) 56: plate member (substrate) 58: spacer 66: semiconductor chip 84: flexible flat cable

Continuing from the front page (72) Inventor Yuhiro Takahashi 2007-1 Kobayashi, Komaki-shi, Aichi Prefecture Colin Electronics Co., Ltd. (72) Inventor Toshimasa Yamazaki 2007-1 Komaki-shi Hayashi, Aichi Prefecture Colin Electronics Co., Ltd. (72) Inventor Masanobu Yasui 2007-1, Komaki-shi, Aichi Prefecture, Korin Electronics Co., Ltd. (72) Inventor Tatsushi Kondo 2007-1, Komaki-shi, Aichi Prefecture, Korin Electronics Co., Ltd. (56) References JP-A-3-15440 (JP, A JP-A-63-293424 (JP, A) JP-A-3-258235 (JP, A) JP-A-55-72903 (JP, U) JP-A-2-141407 (JP, U) 501210 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) A61B 5/0245

Claims (1)

(57) [Claims] 1. A semiconductor chip having a pressure detecting element disposed on a front surface thereof, a spacer member for supporting the semiconductor chip from a back surface, and a substrate to which the spacer member is fixed, wherein the surface of the semiconductor chip is covered. In a contact pressure sensor for detecting a contact pressure by being pressed toward an object generating a measurement pressure, a side wall surface of the spacer member is provided between a connection terminal provided on a surface of the semiconductor chip and the substrate. A contact pressure sensor connected by using a flexible flat cable that rises from the substrate in a state along the line.