JP2001108545A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensor not requiring a large number of electronic components necessary for the amplification of an output signal of a pressure detection element and for input to an opposite computer, to allow miniaturization. SOLUTION: In this pressure sensor, a support plate 39 is provided on the upper face side of a pressure reception substrate 29 through a space part 29a, while a flexible wiring board 41 is fixed on the support plate 39. The flexible wiring board 41 electrically connects an electronic component 43 on the flexible wiring board 41 and terminals 49 in a cover part 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor used for various control devices, automobile engine control, suspension control, and the like.

[0002]

2. Description of the Related Art A conventional pressure sensor of this type is disclosed in Japanese Patent Application Laid-Open No. H11-173930.

Hereinafter, a conventional pressure sensor will be described with reference to the drawings.

FIG. 7 is a side sectional view of a conventional pressure sensor, and FIG.
FIG. 4 is a side sectional view showing a state in which a first terminal is electrically connected to a pressure receiving substrate in the pressure sensor.

[0005] In FIGS. 7 and 8, reference numeral 1 denotes a pressure introducing portion made of metal, and the pressure introducing portion 1 has a pressure introducing hole 2 extending from a substantially central upper surface to a lower surface. Reference numeral 3 denotes a pressure receiving substrate. The pressure receiving substrate 3 is integrally provided on the upper surface of the pressure introducing section 1, and an insulating layer (not shown) is provided on the upper surface. Further, pressure detection is performed on the upper surface of the insulating layer (not shown). An element (not shown), an output electrode (not shown), a power supply electrode (not shown) and a GND electrode (not shown) electrically connected to the pressure detecting element (not shown) are provided. I have. A bridge circuit is formed by these pressure detecting elements and electrodes. Reference numeral 4 denotes a supporting portion made of resin. The supporting portion 4 is provided on a side of the pressure introducing portion 1 and has a pair of first terminals 5. One end is electrically connected to a pressure detecting element (not shown) in the pressure receiving substrate 3 via a wire 3a, and the other end is projected upward. 6 is a circuit board,
The circuit board 6 is provided above the pressure receiving board 3 and has a terminal insertion hole 7. The first terminal 5 of the support portion 4 is inserted through the terminal insertion hole 7 and soldered. And the first terminal 5 is electrically connected to a circuit pattern (not shown) on the circuit board 6. An electronic component 8 is provided on the lower surface of the circuit board 6, and a second terminal 9 electrically connected to the electronic component 8 is provided on a side of the circuit board 6 opposite to the side on which the electronic component 8 is provided. Further, the second terminal 9 has a tip portion protruding upward. Reference numeral 10 denotes a connector portion, which is provided so as to cover the pressure introducing portion 1 and has a connector terminal 11. One end of the connector terminal 11 is electrically connected to the second terminal 9. And the other end is projected upward. Reference numeral 12 denotes a metal mounting base, and the mounting base 12 has a pressure introduction hole 13 extending from a substantially central upper surface to a lower surface.
And the pressure introduction unit 1 is fixed to the upper surface,
The pressure introducing hole 2 in the pressure introducing section 1 and the mounting table 1
The pressure introduction hole 13 in 2 is made to communicate.
The mounting base 12 is provided with a caulking portion 14 so as to protrude upward, and the connector portion 10 is mounted on the upper surface of the mounting base 12 by the caulking portion 14.

Next, the operation of the conventional pressure sensor having the above-described structure will be described. When a substance to be subjected to pressure detection (not shown) is filled in the pressure introducing hole 13 in the mounting base 12 and the pressure introducing hole 2 in the pressure introducing section 1 and pressure is applied to the substance to be pressure detected (not shown). Then, a bending force is applied to the pressure receiving substrate 3. At this time, the resistance of a pressure detecting element (not shown) provided on the upper surface of the pressure receiving substrate 3 changes due to the bending force. The change in the resistance value of the pressure detecting element (not shown) is applied as a voltage to a power supply electrode (not shown) and a GND electrode (not shown) as an output signal from an output electrode (not shown). Is output. After an output signal from the output electrode (not shown) is amplified by the electronic component 8, the amplified output signal is connected to the other terminal via the wire 3 a, the first terminal 5, the second terminal 9, and the connector terminal 11. It is output to a computer (not shown) on the side to detect the pressure of the pressure-detected substance (not shown).

[0007]

However, in the above conventional configuration, the output signal of the pressure detecting element (not shown) is amplified by the electronic component 8 and input to the other computer (not shown). In addition, as parts, wire 3a,
Since many components of the first terminal 5, the circuit board 6, the second terminal 9, and the connector terminal 11 are used, the volume of the entire component is increased, and the size of the pressure sensor is increased. Had issues.

The present invention solves the above-mentioned conventional problems, and requires a large number of components necessary for amplifying an output signal of a pressure detecting element by an electronic component and inputting the amplified signal to a counterpart computer (not shown). It is another object of the present invention to provide a pressure sensor that can be downsized.

[0009]

In order to achieve the above object, a pressure sensor according to the present invention comprises: a cylindrical container having a pressure introduction hole extending from substantially the center of the upper surface to substantially the center of the lower surface; A pressure receiving substrate having an outer peripheral portion fixed to the bottom surface and having at least a pair of pressure detecting elements, a power supply electrode, a GND electrode, and an output electrode electrically connected to the pressure detecting element; and a position above the pressure receiving substrate. A flexible wiring board provided on an upper surface with an electronic component for processing a signal generated from at least a pair of pressure detecting elements in the pressure receiving substrate and outputting an output signal, and accommodating the flexible wiring board inside And a cover portion provided so as to protrude outwardly a terminal electrically connected to the electronic component, and a space portion on an upper surface side of the pressure receiving substrate via a space portion. A supporting plate is provided, and the flexible wiring board is further fixed to the support plate, and electronic components in the flexible wiring board and terminals in the cover portion are electrically connected by the flexible wiring board. For example, it is possible to provide a pressure sensor capable of amplifying an output signal of the pressure detecting element by an electronic component and not requiring many components necessary for inputting the signal to a mating computer (not shown), thereby achieving downsizing. Things.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a cylindrical container provided with a pressure introduction hole extending from substantially the center of the upper surface to substantially the center of the lower surface, and an outer peripheral portion of the bottom surface on the upper surface of the container. And a pressure receiving substrate having at least a pair of pressure detecting elements, a power electrode electrically connected to the pressure detecting elements, a GND electrode and an output electrode,
A flexible wiring board which is provided above the pressure receiving substrate and has on its upper surface an electronic component for processing a signal generated from at least a pair of pressure detecting elements in the pressure receiving substrate and outputting an output signal; A cover portion that accommodates the wiring board inside and that is provided with a terminal electrically connected to the electronic component so as to protrude outward; and a support plate via a space on the upper surface side of the pressure receiving substrate. Provided, furthermore, the flexible wiring board is fixed to the support plate, and the electronic components in the flexible wiring board and the terminals in the cover portion are electrically connected by the flexible wiring board. According to this configuration, A support plate is provided on the upper surface side of the pressure receiving substrate via a space portion, and the flexible wiring board is further fixed to the support plate. Since the electronic components in the cover and the terminals in the cover portion are electrically connected by the flexible wiring board, the output signal of the pressure detecting element in the pressure receiving board is transmitted to the counterpart via the electronic components, the flexible wiring board and the terminals in the cover portion. As a result, the output signal of the pressure detecting element is amplified by electronic components, and the number of components necessary for inputting to the other computer is reduced, so that the pressure sensor can be downsized. It has the effect of being able to achieve.

According to a second aspect of the present invention, a spacer is provided between the pressure receiving substrate and the supporting plate of the first aspect,
With this spacer, a space is formed between the pressure receiving substrate and the support plate. According to this configuration, a spacer is provided between the pressure receiving substrate and the support plate, and the pressure Because the space between the substrate and the support plate is formed, the pressure in the pressure introducing hole increases, so that even if the center of the pressure-receiving substrate is deformed upward, the pressure-receiving substrate remains in the space. Due to its existence, it does not come into contact with the support plate. As a result, the output of the pressure detecting element on the pressure receiving substrate is stabilized, and it is very easy to provide the spacer between the pressure receiving substrate and the support plate. Therefore, the pressure sensor having a stable output can be easily obtained.

According to a third aspect of the present invention, a first hole is provided in the support plate according to the first or second aspect, and a second hole is provided in the flexible wiring board. And a power supply electrode, an output electrode and a GN on the electronic component and the pressure receiving board.
The D electrode is electrically connected. According to this configuration,
A first hole is provided in the support plate, a second hole is provided in the flexible wiring board, and wires are provided in the first hole and the second hole. Since the electrode, the output electrode, and the GND electrode are electrically connected, the power supply electrode, the output electrode, and the GND electrode on the electronic component and the pressure receiving substrate can be arranged substantially linearly, and thereby, the wire is routed. Since it is not necessary, it has an effect that bonding can be easily performed.

Hereinafter, a pressure sensor according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view of a pressure sensor according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the pressure sensor with a cover removed, and FIG. 3 is a view of the pressure sensor with the cover removed. FIG. 4 is a top view of the flexible wiring board in the same pressure sensor.

1 to 4, reference numeral 21 denotes, for example, SUS.
430 is a cylindrical container made of metal,
The container 21 has a pressure introduction hole 22 extending from substantially the center of the upper surface to substantially the center of the lower surface. The pressure introducing hole 22 of the vessel 21 is provided with a small-diameter portion 23 having an inner diameter of 2.4 mm located on the upper portion and having an inner diameter of 2.0 mm located on the upper portion of the small-diameter portion 23. The smallest diameter portion 24 is provided. The outside diameter of the pressure introducing hole 22 is 2.3 mm inside the small diameter portion 23 except for the smallest diameter portion 24.
An elastic member 25 made of a coil spring is provided,
The elastic member 25 is housed in the small-diameter portion 23 of the pressure introducing hole 22 by bringing the upper end into contact with the outer periphery of the lower end of the smallest-diameter portion 24. Further, a large diameter portion 26 having an inner diameter of 2.6 mm is provided below the pressure introducing hole 22, and a sphere 27 made of a metal hard sphere having a diameter of 2.5 mm is provided inside the large diameter portion 26.
Is stored. The sphere 27 is configured so that the diameter is larger than the inner diameter of the small diameter portion 23 in the pressure introducing hole 22 and smaller than the inner diameter of the large diameter portion 26, and the sphere 27 is formed of the elastic member. The elastic member 25 is in contact with the lower end of the elastic member 25 and is urged downward. Further, a cylindrical metal stopper 28 having an inner diameter smaller than the diameter of the sphere 27 is fitted to the inner surface of the pressure introducing hole 22 below the large diameter portion 26.

Reference numeral 29 denotes a pressure-receiving substrate made of a metal such as SUS631CSP in the form of a disk having a diameter of 2.7 mm and a thickness of 0.4 mm. The pressure-receiving substrate 29 has the outer peripheral portion of the bottom surface fixed to the upper surface of the container 21. In addition, a pair of inner pressure detecting elements 30 and a pair of outer pressure detecting elements 31 made of a metal thin film resistor are provided on the surface. On the surface of the pressure receiving substrate 29, a first power supply electrode 32, a second power supply electrode 33, a first output electrode 34,
Output electrode 35, first GND electrode 36 and second G electrode
ND electrodes 37 are provided, and these electrodes are connected to the pair of inner pressure detecting elements 30 and the pair of outer pressure detecting elements 3.
A bridge circuit is formed by electrically connecting the bridge circuit 1 to the bridge circuit. A spacer 38 made of a metal such as SUS301CSP is provided in a disk shape having an inner diameter of 6.2 mm, an outer diameter of 7.2 mm, and a thickness of 50 μm on an outer peripheral portion of an upper surface of the pressure receiving substrate 29. For example, SUS63 having an outer diameter of 7.2 mm and a thickness of 0.2 mm
A metal support plate 39 made of 1CSP is provided. The support plate 39 has a pair of first holes 40. Reference numeral 41 denotes a flexible wiring board. The flexible wiring board 41 has a pair of second holes 42,
The electronic component 43 is placed substantially at the center of the upper surface. Then, the first output electrode 34 and the second
Is electrically connected to the electronic component 43 via the first hole 41 and the second hole 42 by connecting a wire 44 made of aluminum with a diameter of 30 μm to the pair of inner pressure detecting elements 30 and the pair of inner pressure detecting elements 30. The signal generated from the outside pressure detecting element 31 is output as an output signal.

Reference numeral 45 denotes a resin cover.
Is formed by a cylindrical tubular portion 46 provided so as to surround an upper portion of the outer surface of the container 21, a support portion 47 for fixing the upper portion of the tubular portion 46, and a holding portion 48 supported by the support portion 47. It is configured. And the cover part 4
5 accommodates the flexible wiring board 41 inside and insert-molds a terminal 49 penetrating from above to below integrally with the holding portion 48, and this terminal 49 is an electronic component provided on the flexible wiring board 41. 43 is electrically connected via a wiring pattern (not shown) on the flexible wiring board 41. A support plate 39 is provided on the upper surface side of the pressure receiving substrate 29 via a space portion 29a. Further, the flexible wiring board 41 is fixed to the support plate 39. As described above, the terminal 49 of the cover 45 is electrically connected to the flexible wiring board 41, so that the output signals of the pair of inner pressure detecting elements 30 on the pressure receiving board 29 are output from the electronic component 43 and the flexible wiring board. A counterpart computer (not shown) via a terminal 41 in the cover 41 and the cover unit 45
As a result, the output signals of the pair of inner pressure detecting elements 30 and the pair of outer pressure detecting elements 31 are amplified by the electronic component 43 and the components necessary for inputting to the other computer are also included. This has the effect of requiring less.

Next, a method of assembling the pressure sensor according to the embodiment of the present invention configured as described above will be described.

First, a pair of inner pressure detecting elements 30, a pair of outer pressure detecting elements 31, a first power electrode 32, a second power electrode 33, a first GND electrode 36, a second , The first output electrode 34 and the second output electrode 35 are formed by sputtering.

Next, a bridge circuit is formed on the surface of the pressure receiving substrate 29 by etching.

Next, the small-diameter portion 23 and the smallest-diameter portion 2 extend from the upper surface to the lower surface of the cylindrical container 21 made of metal.
The pressure introduction hole 22 composed of the diameter 4 and the large diameter portion 26 is formed.

Next, after the elastic member 25 made of a coil spring is accommodated in the small-diameter portion 23 of the container 21, the sphere 27 is moved to the large-diameter portion 26 of the pressure introducing hole 22 so as to contact the lower end of the elastic member 25. To be stored.

Next, a stopper 28 for preventing the spherical body 27 from coming off is fitted to the lower part of the large-diameter portion 26 of the container 21.

Next, the outer peripheral portion of the bottom surface of the pressure receiving substrate 29 is fixed to the upper surface of the container 21 by projection welding.

Next, after a pair of first holes 40 are formed in the support plate 39, a flexible wiring board 41 provided with a pair of second holes 42 in advance is fixed to the upper surface of the support plate 39.

Next, after the spacer 38 is fixed to the lower surface of the support plate 39, the lower surface of the spacer 38 is attached to the upper surface of the pressure receiving substrate 29. By providing the spacer 38 between the lower surface of the support plate 39 and the pressure receiving substrate 29, a space 29a is formed between the pressure receiving substrate 29 and the support plate 39 as shown in FIG. Due to the increase in the pressure in the pressure introducing hole 22, even if the center of the pressure receiving substrate 29 is deformed upward, the pressure receiving substrate 29 does not contact the support plate 39 due to the presence of the space 29a.
As a result, the outputs of the pair of inner pressure detecting elements 30 and the pair of outer pressure detecting elements 31 on the pressure receiving substrate 29 are stabilized, and the spacer 38 is connected to the pressure receiving substrate 29 and the support plate 3.
Because it is very easy to provide between 9 and
It is possible to easily obtain a pressure sensor having a stable output.

Next, after the electronic component 43 is fixed to the upper surface of the flexible wiring board 41 with an adhesive, the first power supply electrode 32, the second power supply electrode 33, The second hole 42 provided in the flexible wiring board 41 with the output electrode 34, the second output electrode 35, the first GND electrode 36, and the second GND electrode 37
The wire 44 is electrically connected by bonding a wire 44 through a first hole 40 provided in the support plate 39. Thus, while the first hole 40 is provided in the support plate 39, the second hole 42 is provided in the flexible wiring board 41,
A wire 44 is disposed in the first hole 40 and the second hole 42, and the first power electrode 32, the second power electrode 33, and the first power electrode 32 on the electronic component 43 and the pressure receiving board 29 are provided by the wire 44. The output electrode 34, the second output electrode 35, the first
By electrically connecting the GND electrode 36 and the second GND electrode 37 to each other, the first power supply electrode 32, the second power supply electrode 33,
Since the output electrode 34, the second output electrode 35, the first GND electrode 36, and the second GND electrode 37 can be arranged substantially linearly, there is no need to route the wire 44, and as a result, This has an effect that bonding can be easily performed.

Next, the terminal 4 is formed by molding a resin.
9 is integrally formed by insert molding.

Next, after electrically connecting terminals 49 of the holding portion 48 to electrodes (not shown) of the flexible wiring board 41 by soldering, the holding portion 48 is connected to the cylindrical portion 4.
6 on the upper surface.

Finally, the outer surface of the cylindrical portion 46 and the holding portion 4
8 is fixed by the support portion 47.

Next, the operation of the pressure sensor according to the embodiment of the present invention assembled as described above will be described.

When the internal pressure of the mating pressure introducing pipe (not shown) increases, the pressure receiving substrate 29 of the pressure sensor deforms outward. Along with the deformation of the pressure receiving substrate 29, the pair of outer pressure detecting elements 31 provided on the pressure receiving substrate 29 are contracted by a compressive force.
0 changes in the direction of elongation due to tensile force. Here, the resistance value of a pressure detecting element composed of a resistor such as a metal thin film resistor is generally proportional to the length L of the resistor and the specific resistance ρ, and inversely proportional to the cross-sectional area s. Therefore, the pair of outer pressure detecting elements 31 and the pair of inner pressure detecting elements 3
A resistance value R of 0 increases as the resistor expands, while
When the resistor shrinks, the resistance becomes smaller. Therefore, the resistance value of the pair of outer pressure detecting elements 31 and the pair of inner pressure detecting elements 30 formed by the bridge circuit is determined by the resistance of the mating pressure introducing pipe (not shown). When the inner pressure increases, the resistance of the pair of inner pressure detecting elements 30 becomes larger than the resistance of the pair of outer pressure detecting elements 31. Therefore, the first output electrode 34 and the second output electrode 3 forming a bridge circuit
The pressure applied to the pressure sensor can be measured by outputting and measuring a potential difference from the pressure sensor 5.

In the pressure sensor according to the embodiment of the present invention, the spacer 38 is provided between the pressure receiving substrate 29 and the support plate 39 so that the distance between the pressure receiving substrate 29 and the support plate 39 is increased. The protrusion 29 is provided integrally with the support plate 39 over the entire outer periphery of the lower surface of the support plate 39, as shown in FIG. 5, or as shown in FIG. Even if a plurality of protrusions 51 are provided on the outer peripheral side of the lower surface of the lower surface 39 to form a space between the pressure receiving substrate 29 and the support plate 39, the same effect as in the embodiment of the present invention can be obtained. Have

[0034]

As described above, the pressure sensor of the present invention has a cylindrical container provided with a pressure introducing hole extending from substantially the center of the upper surface to substantially the center of the lower surface, and the outer peripheral portion of the bottom surface is fixed to the upper surface of the container. And at least one pair of pressure detecting elements,
A power electrode electrically connected to the pressure detecting element, GN
A pressure receiving substrate having a D electrode and an output electrode, and an electronic component provided above the pressure receiving substrate and configured to process a signal generated from at least a pair of pressure detecting elements in the pressure receiving substrate and output an output signal. A flexible wiring board provided on the upper surface thereof, and a cover portion for housing the flexible wiring board inside and providing a terminal electrically connected to the electronic component so as to protrude outward. A support plate is provided on the upper surface side of the substrate via a space portion, and the flexible wiring board is further fixed to the support plate, and electronic components in the flexible wiring board and terminals in the cover portion are electrically connected by the flexible wiring board. According to this configuration, a support plate is provided on the upper surface side of the pressure receiving substrate via a space, and the support plate is further provided on the support plate. Since the electronic components of the flexible wiring board and the terminals of the cover are electrically connected to each other by the flexible wiring board, the output signal of the pressure detecting element on the pressure receiving board is an electronic component, The signal is output to the mating computer via terminals on the wiring board and the cover, and as a result, the components necessary for amplifying the output signal of the pressure detecting element by electronic components and inputting to the mating computer are also included. Since it requires only a small amount, the pressure sensor has an excellent effect that the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a pressure sensor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a state where a cover is removed from the pressure sensor.

FIG. 3 is a side sectional view showing a state where a cover is removed from the pressure sensor.

FIG. 4 is a top view showing a state where electronic components are mounted on a flexible wiring board in the pressure sensor.

FIG. 5 is a lower perspective view of a spacer in a pressure sensor according to another embodiment of the present invention.

FIG. 6 is a lower perspective view of a spacer in a pressure sensor according to another embodiment of the present invention.

FIG. 7 is a side sectional view of a conventional pressure sensor.

FIG. 8 is a side sectional view showing a state in which a first terminal is electrically connected to a pressure receiving substrate in the pressure sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Container 22 Pressure introduction hole 29 Pressure receiving substrate 29a Space 30, 31 Pressure detection element 32, 33 Power supply electrode 34, 35 Output electrode 36, 37 GND electrode 38 Spacer 39 Support plate 40 First hole 41 Flexible wiring board 42 Second Hole 43 electronic component 44 wire 45 covering part 49 terminal

Claims (3)

[Claims] 1. A cylindrical container having a pressure introduction hole extending from substantially the center of the upper surface to substantially the center of the lower surface, an outer peripheral portion of the bottom surface is fixed to the upper surface of the container, and at least one pair of pressure detecting elements. A pressure receiving substrate having a power supply electrode, a GND electrode, and an output electrode electrically connected to the pressure detecting element; and a pressure receiving substrate provided above the pressure receiving substrate and generated from at least one pair of pressure detecting elements in the pressure receiving substrate. A flexible wiring board provided on the upper surface with an electronic component for processing a signal to be output and outputting an output signal, and accommodating the flexible wiring board inside, and projecting a terminal electrically connected to the electronic component outward. And a cover portion provided on the upper surface side of the pressure receiving substrate via a space portion, and further, the flexible wiring board is fixed to the support plate. A pressure sensor in which electronic components of the flexible wiring board and terminals of the cover are electrically connected by the flexible wiring board. 2. The pressure sensor according to claim 1, wherein a spacer is provided between the pressure receiving substrate and the support plate, and a space is formed between the pressure receiving substrate and the support plate by the spacer. 3. A first hole is provided in the support plate, a second hole is provided in the flexible wiring board, and wires are provided in the first hole and the second hole.
3. The pressure sensor according to claim 1, wherein the power supply electrode, the output electrode, and the GND electrode of the pressure receiving board are electrically connected to the electronic component.