JPS63155674A - Distributed type sensor for sense of contact force - Google Patents

Abstract

PURPOSE:To obtain a sensor which has high sensitivity and exhibits an excellent linearity by placing a single crystalline silicon plate on an elastic body, thereby detecting a state of deformation of single crystalline silicon plate accompanied by an elastic deformation through resistance variations of a semiconductor strain gauge that is placed on the above silicon plate. CONSTITUTION:A plurality of contact force sensation detecting devices 12 are mounted on an elastic body 11. And protruding parts 14 that are regulated by grooves 13 like well cribs are installed to the elastic body 11 so as to isolate the devices 12. A single crystal silicon plate 15 where a semiconductor strain gauge is formed on its surface is glued on the elastic body 11. In addition to the semiconductor strain gauge and its interconnection which is required to combine its gauge, soldering pads 16 for picking up signals are formed on the silicon plate 15. Further, a load impressing part 17 is formed on the silicon plate 15. The impressing part 17 is composed of rigid members and is glued to its silicon plate 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distributed pressure sensor capable of detecting the distribution of force applied in the vertical direction.

[Prior art] As a distributed pressure sensor for detecting the distribution of force applied in the perpendicular direction to the hunt, it is attached to a robot, etc., and uses a conductive comb or plastic as a detection element. It has been proposed. FIG. 6 shows an example of this, in which two layers of four thin electrically conductive rubber strips 1.2, which are perpendicular to each other, are combined. When a force is applied in a direction perpendicular to the comb strip array surface of the pressure sensor, the area of the contact portion of the conductive comb strips 1.2 increases and the resistance changes.

However, in distributed pressure sensors that use conductive rubber like this, the area of the contact part does not necessarily change in proportion to the applied force, so the resistance value change of the contact part does not necessarily change in proportion to the force. The sensor output becomes non-wire: I', and the voltage terminal and ground terminal.

IU, the terminal is open. Article 14, Connection, 7 Yuwa, Yo.

Since there is no .chi.L, there are drawbacks such as the number of wires required to detect the force distribution with high density.

FIG. 8 shows another conventional example in which a Hall element 7 attached to a sensor head 1-6 is opposed to a fixed magnet 8, and when a vertical force is applied to the sensor head 6, the Hall element 7 The magnitude of the applied force is determined by displacing the force against the spring 9 and detecting the change in the magnetic flux reduction coefficient. An attempt is made to find the force distribution by arranging a large number of such sensors. However, in such a distributed pressure sensor, the mechanism for displacing the pole element in response to the applied force is complicated, so it is impossible to increase the distribution density of the sensor, and the power outage described above may occur. As with the example of comb strips, there are drawbacks such as an increase in the number of wires.

[Problem that the invention seeks to solve]

As mentioned above, conventional distributed pressure sensors have drawbacks such as (1) the output is not proportional to the force, (2) the number of wires is large, and it is difficult to increase the distribution density of the sensor. .

The purpose of the present invention is to provide a distributed pressure sensor that is easy to install.

[Means to solve the problem]

In order to achieve such an object, the distributed pressure sensor of the present invention is provided by disposing a single crystal silicon plate formed with a semiconductor strainer on an elastic member having a relatively small elasticity. The present invention is characterized in that a plurality of detection elements configured to detect the applied vertical stress by changes in the electrical resistance value of the semiconductor strain case are arranged in an array on the fixed plate.

[Effect]

In the distributed pressure sensor of the present invention, when a vertical force is applied to a single-crystal silicon plate, the single-crystal silicon deforms together with the elastic material, and the resistance value of the semiconductor strain gauge formed on the single-crystal silicon is By detecting the change in the force, the magnitude of the force in the direction perpendicular to the plate is detected, so the output sensitivity of the pressure sensing element is increased, and since the linearity of the output is well used, the wiring density can be increased. As a result, the distribution density of the pressure sensing elements can be increased.

In addition, since the single crystal silicon plates forming the semiconductor strain case are arranged in an array on a fixed plate of a robot hunt, etc. through an elastic material such as plastic or rubber with a relatively small Young's modulus, there is a certain degree of curvature. It can be mounted on any surface that has a similar shape, and can be easily attached to a robot hunt.

〔Example〕

FIG. 1 is a sectional view showing an embodiment of the present invention.
A plurality of pressure sensing elements 12 are provided on the top. In order to separate the pressure sensing element 12, the elastic body 11 is provided with a protrusion 14 whose periphery is regulated by a cross-shaped groove 13 that is machined from two parts. On this elastic body 11, a single crystal silicon plate 15 having a semiconductor strain gauge formed on its surface is adhered. On the single crystal silicon plate 15,
In addition to semiconductor strain gauges and wiring connecting them, it is also possible to form 1.16. A load applying section 17 is further formed on the single crystal silicon plate 15''.

The load applying section 17 is made of a rigid member, and may be bonded to a single crystal silicon plate (temporary), or a solder plating layer may be formed on the surface of the single crystal silicon plate 15 by the method described above.
A load applying section 17 made of metal or the like is connected to a single crystal silicon plate 15.
It may be soldered.

The pressure sensing element 12 is constituted by the projection 14 of the elastic body 11 whose periphery is regulated by the cross-shaped groove 13, the single crystal silicon plate 15, and the load application part 17, which are arranged in a matrix. It constitutes a distributed pressure sensor.

Furthermore, the surface of the distributed pressure sensor is
A flexible printed board 18 having copper wiring covers the surface facing 5. The flexible printed board 18 has a wiring pattern formed on both sides and further has a window 19. By inserting the load applying section 17 into this window, the relative positioning of the pressure sensing element 12 and the flexible printed board 18 is performed. Being cheated on. The solder pads 16 and 20 are melted and bonded using a flow or laser heating method, and the signal from the pressure sensing element 12 is extracted, and the flexible printed board 18 and the single crystal silicon plate 15 are also mechanically bonded. There is.

This distributed pressure sensor may be mounted on the fixed plate 21 by adhesive or mechanical means, or the fixed plate 21 may be a Rohot Hunt surface.

FIG. 2 shows the state of the surface of the single crystal silicon plate 15 in more detail, and the surface has the above-mentioned H/V top hat 16, the load applying section 17, and four points at the positions described below. Strain gauges 22A, 22B, 22C, and 22D are formed, and a wheatstone bridge is constructed by wiring (not shown). S1-Len case 228-22
D is a resistance layer in which impurities are diffused by a conventional semiconductor process.

Next, the positions where the thread cages 228 to 22D are formed will be explained. FIG. 3 shows a pressure sensing element 12 of the present invention.
Pβ y−□ φ (βX ) (1
) k :, 21 where, k1 the modulus of the elastic floor '□, ;-2' P, the applied force E, the Young's modulus of the beam I7: the second moment of area of the beam, and φ (βx), ψ (β The values of x) are shown in FIG. The stress generated in the beam is proportional to the moment M at that point.
χ≦0), the absolute value of ψ is sharp. Therefore, it can be seen that crystal-sensitive output characteristics can be obtained by forming the stress-detecting grooves near the load application point. The slider in FIG. 2 is in the position thus determined.

When a force is applied to the load applying section 17, the single crystal silicon plate 15 is deformed together with the protrusion 14 of the elastic body 11. At this time, bending stress acts on the strain gauges 22A and 22D, causing a change in resistance, but almost no change in resistance occurs in the strain gauges 22B and 22G. Therefore, the magnitude of the force applied to the load applying section 17 can be known from the voltage change in the bridge circuit.

Furthermore, by scanning the plurality of pressure sensing elements 12 arranged in a matrix row by row and column, it is possible to extract the signal of each pressure sensing element 12 and find out the distribution of the applied force.

FIG. 5 shows another embodiment, in which the elastic body 11
The groove 13 that is machined is machined from below into a parallel cross shape to form a protrusion 14. The other configurations are completely the same as the first embodiment. With this configuration, even if the fixed plate 21 has a certain degree of curvature, the elastic body 11 can be bent and attached along the curvature.

〔Effect of the invention〕

As explained above, according to the present invention, a single crystal silicon plate is placed on an elastic material having a relatively small Young's modulus such as rubber or plastic, and the single crystal silicon plate is deformed together with the elastic material. Since a flexible printed board is used, wiring density can be increased. Further, the pressure sensor of the present invention can be mounted on a surface with a certain degree of curvature, and can be easily attached to a robot hunt.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing an embodiment of the present invention, Figure 2 is a plan view of a single crystal silicon plate which is one of the components of the present invention, and Figure 3 is a diagram showing the principle of load detection of the present invention. Schematic figure 4 is a diagram showing the values of the functions φ and ψ in the text, figure 5 is a sectional view showing another embodiment of the present invention, figure 6 is a perspective view of a conventional distributed pressure sensor, FIG. 7 is an explanatory diagram of the measuring method, and FIG. 8 is a side view showing another example of a conventional distributed pressure sensor. DESCRIPTION OF SYMBOLS 11... Elastic body, 14... Projection, 15... Single crystal silicon plate, 16... Solder pad, 17... Load application part, 18... Flexible printed board, 20. ...Solder pad, 21...Fixing plate, 228, 22B, 22C, 22D...Strain gauge. □臥 臉芉情F Yuiizuka Kozo 1 Gumu Δ Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1) A single-crystal silicon plate on which a semiconductor strain gauge is formed is disposed on an elastic member having a relatively small elastic modulus, and vertical stress applied to the silicon plate is applied to the semiconductor strain gauge. 1. A distributed pressure sensor comprising: a plurality of detection elements arranged in an array on a fixed plate, each of which is configured to detect based on a change in the electrical resistance value of the sensor. 2) The distributed pressure sensor according to claim 1, wherein the elastic material having a relatively small Young's modulus is plastic or rubber. 3) The distributed pressure sensor according to claim 1, characterized in that a flexible printed board is used as wiring for extracting changes in resistance of a semiconductor strain gauge formed on single crystal silicon. Distributed pressure sensor.