JPH03269331A - Pressure sensor - Google Patents

Abstract

PURPOSE:To easily arrange plural pressure sensors connected like an array on the same plane in a connected state with the same density by connecting the element mounting part of the 1st pressure sensor to the mounting part of the 2nd pressure sensor on the same plane through a bent part. CONSTITUTION:The 1st pressure sensor array 1A is fixed on a supporting base 10 through a spacer 12. Another spacer 12 is arranged on the upper surface of the shift register mounting part 5 of the array 1A and the 2nd pressure sensor array 1B is superposed to the space 12 so that the element mounting part 3 of the array 1B is positioned on the spacer 12. The wiring connection terminals 6 of the array 1A are connected to the connecting terminals 13 of the array 1B by this superposition. An interval P2 between respective pressure receiving parts 8 adjacent through the bent part 11 is made equal to an interval P1 between other adjacent pressure receiving parts 8 by properly selecting the bent angle of the bent part 11. Thus, the pressure receiving parts 8 can be distributed with the same pitch over two element mounting parts 3.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a pressure sensor, and more specifically, the present invention relates to a pressure sensor that can be mounted on a robot hand or the like to detect the distribution of force applied in a direction perpendicular to the mounting surface. The present invention relates to pressure sensors arranged in a possible array.

[Prior Art] Conventionally, such pressure sensors have been proposed in which a combination of conductive rubber or plastic is used as a detection element. FIG. 4 shows one example of this, which is constructed by combining two layers of thin conductive rubber strips 15 and 16 orthogonal to each other. When a vertical force is applied to the rubber strip arrangement surface of this pressure sensor, the area of the contact portion between the conductive rubber strips 15 and 16 increases and the electrical resistance changes. Therefore, as shown in FIG. 5, by applying a voltage of, for example, 5V to the voltage terminal 17 through a 1000Ω resistor 18 and measuring the voltage at the output point 19, the magnitude of the applied force can be determined. .

6A and 6B show another conventional example, in which a semiconductor strain gauge (not shown) is formed, a load detection element 20 having a load application part, and a printed wiring board 21 on which these load detection elements 20 are mounted. This is an example of a pressure sensor arranged on an array and configured with wiring 22 for extracting signals from a printed wiring board 21. Figure 8 shows the wiring of the circuit. In this conventional example, one of the groups of load sensing elements 20 arranged in one horizontal row is selected by the control wiring 23, and one of the groups of load sensing elements 20 arranged in one vertical column is further selected by the signal line 24. Accordingly, one load detection element 20 located at the point where the two intersect is selected.

Note that Figures 7A and 7B are similar to Figures 6A and 6B.
This is an example in which the detection area is expanded by further connecting and arranging a plurality of pressure sensors shown in the figure.

[Problem to be solved by the invention]

However, in the conventional pressure sensor shown in the first example shown in Fig. 4, the area of the contact part does not necessarily change in proportion to the applied force, and therefore the resistance value of the contact part The change is not proportional to the force and the sensor output becomes non-linear, and the power supply terminal, ground terminal, and output terminal must be connected to each rubber strip, so it is difficult to detect the force distribution in a high density. There are drawbacks such as an increase in the number of wiring lines.

In addition, the pressure sensor shown in the second example of the conventional technology shown in FIGS. 6A and 6B has problems such as non-linear sensor output and a large number of wires in the first example described above. However, in order to combine and arrange multiple array pressure sensors on the same plane, not only does the mounting density of the load sensing elements decrease, but the number of wires increases in proportion to the number of arrays. There is a drawback.

An object of the present invention is to focus on the above-mentioned conventional problems, and to solve the problems, it is an object of the present invention to easily arrange pressure sensors arranged in an array on the same plane at the same density in a connected state, and to solve the problems. Another object of the present invention is to provide a pressure sensor that does not require an increase in the number of wiring lines and can save space.

[Means to solve the problem]

In order to achieve such an object, the present invention provides a plurality of load detection systems having a pressure receiving section protruding to receive a load and a semiconductor strain gauge for detecting strain caused by the load from the pressure receiving section. an element mounting part of a flexible wiring board that holds elements in an array and has wiring to the plurality of load detection elements; and an element mounting part of a flexible wiring board that extends from the flexible wiring board and processes signals from the plurality of load detection elements. a processing circuit mounting part on which a circuit is mounted; a bendable part provided at a connecting part between the element mounting part and the processing circuit mounting part and capable of forming a step between both the mounting parts; Extended from the flexible wiring board of the circuit mounting section,
and a wiring connection part having a wiring terminal for connection to which wiring from the processing circuit mounting part can be connected to the outside, wherein a second pressure sensor is provided on the processing circuit mounting part of the first pressure sensor. The sensor element mounting parts can be mounted on top of each other,
In the attached state, the element mounting part of the first pressure sensor and the mounting part of the second pressure sensor are arranged in succession on the same plane via the bent part. It is.

[For production]

According to the present invention, by providing the bent part between the element mounting part and the processing circuit mounting part, a step is formed so that the element mounting part of the next pressure sensor is overlapped on the processing circuit mounting part. In this way, a high-density pressure sensor array is constructed by sequentially overlapping multiple pressure sensors. can do. In addition, by providing a connecting terminal on the flexible wiring board of such a pressure sensor, when two pressure sensors are mounted on top of each other in a shifted state, the connecting terminal of one can be connected to the other. Since it can be connected to the connection wiring terminal, there is no need to increase the number of wires for external extraction.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

First of all, in order to make the main points of the configuration of the present invention easier to understand, Section 3A
An example of a basic form of an array pressure sensor to which the present invention can be applied is shown in basic units by the figure and FIG. 3B. In these figures, a pressure sensor (sensor l) includes an element mounting part 3 in which a plurality of sensor elements 2 are arranged in an array, and a shift register 4 connected to wiring (not shown) extending from the element mounting part 3. a shift register mounting section 5 (processing circuit mounting section), and wiring (not shown) further extending from the shift register mounting section 5 and connected to an external signal processing device or cable (not shown). It is composed of a wiring connection section 7 having a connection terminal 6.

Each sensor element 2 has a pressure receiving part (mesa) 8 protruding from a silicon plate, and further includes a plurality of semiconductor strain gauges (not shown), a Wheatstone bridge circuit in which the semiconductor strain gauges are incorporated, and a power supply to the circuit. Wiring for signal extraction, solder bumps for connection, ground, switch means for element selection, etc. are formed on a silicon plate, and each sensor element 2 is electrically connected to a flexible wiring board 9. has been done. Reference numeral 10 denotes a support substrate in which a recess 11 is formed at the mounting position of the shift register 4, which supports the element mounting section 3 and the shift register mounting section 5 as shown in FIG. 3B, and supports the shift register 4.
is protected.

In the present invention, for the pressure sensor 1 having the above-described configuration, a plurality of pressure sensors are connected in a continuous, planar and compact manner, so that an array-like pressure sensor with high element density can be obtained. Examples are shown in Figures 1A and 1B.
As shown in the figure. In FIG. 1A, IA and IB each represent a basic unit pressure sensor (hereinafter referred to as a pressure sensor array as it is a basic unit in which a plurality of sensor elements 2 are formed in an array), and in FIG. In the state shown in (B), the second pressure sensor array IA is
The pressure sensor array IB shown in FIG.

Further, FIG. 1B is a plan view of the state shown in FIG. 1A (B) viewed from above.

First, the configurations of the individual pressure sensor arrays LA and IB will be described. The pressure sensor arrays are each shown in FIG. 1A (
As shown in A), there is a bending part 11 that is folded twice at a predetermined angle between the element mounting part 3 and the shift register mounting part 5, and has a shape and thickness that are easy to bend, and the shift register mounting part 5 A spacer 12 having a trapezoidal cross section as shown is attached to the upper surface of the spacer. Further, reference numeral 13 denotes a connection terminal formed on the lower surface side of the boundary between the shift register mounting section 5 and the wiring connection section 7.

Therefore, these two pressure sensor arrays IA and IB
To connect and integrate the first pressure sensor array IA as shown in FIG. 1A (B), first
It is attached on O via a spacer 12. Next, a spacer 12 is placed again on the upper surface of the shift register mounting portion 5, and the elements are stacked so that the element mounting portion 3 of the second pressure sensor array IB is positioned on the spacer 12. By this superposition, the wiring connection terminal 6 of the first pressure sensor array IA is
The connecting terminal 13 of the second pressure sensor array 1B can be connected to the connecting terminal 13 of the second pressure sensor array 1B.

Here, when setting the bent portion 11 and spacer 12 in each pressure sensor array IA, IB, by appropriately selecting the bending angle, the adjacent pressure can be received through the bent portion 11 as shown in FIG. 1B. It is preferable that the spacing P2 between the portions 8 be equal to the spacing Pl between the other pressure receiving portions 8. By doing so, the pressure receiving parts 8 can be distributed at the same pitch over the two element mounting parts 3.

FIG. 2 shows the circuit configuration of the pressure sensor arrays LA and IB described above. According to this embodiment, even if a plurality of pressure sensor arrays are connected in this way, connection wiring for signal extraction is required for the 4×4 sensor elements 2 arranged for each element mounting section 3. It turns out that only 7 pieces is enough. In this way, a plurality of pressure sensor arrays can be connected one after another on the same plane, the density of these sensor elements can be maintained at the same level, and there is no need to specifically increase the number of wires.

〔Effect of the invention〕

As described above, according to the present invention, a bendable double-fold structure is provided between an element mounting part in which a plurality of sensor elements are arranged in an array and a shift register mounting part connected to the element mounting part. By providing a bent part and holding the element mounting part on the spacer so that a step is created by the bent part between the element mounting part and the shift register mounting part, It is possible to configure the next element mounting part to be mounted overlappingly, and also to connect the side overlapped with the flexible wiring board between the shift register mounting part and the wiring connection part connected thereto. By providing a connection terminal that can be connected to a terminal, the number of wires drawn out from multiple pressure sensors can be reduced even if they are stacked one after another and connected to one flat plate 12 as described above. It is possible to provide a pressure sensor having a compact and high-density sensor element array without the need to increase the number of sensor elements.

[Brief explanation of drawings]

FIG. 1A is a sectional view showing an embodiment of the present invention in the process of connection; FIG. 1B is a plan view showing an embodiment of the present invention in a connected state; FIG. 2 is a circuit on a flexible wiring board according to the present invention. 3A and 3B are a plan view and a sectional view showing the structure of a pressure sensor of the same type before the present invention is applied. FIG. 4 is a perspective view showing the structure of a pressure sensor according to the prior art. 6A and 6B are plan views and side views showing the configuration of a second example of a pressure sensor according to the prior art. FIGS. 7A and 7B are block diagrams of the detection circuit shown in FIG. FIG. 8 is a plan view and a side view showing an example of connection of the pressure sensor shown in FIGS. 6A and 6B, and FIG. 8 is a circuit diagram between elements of the pressure sensor shown in FIGS. 6A and 6B. 1, IA, IB...Pressure sensor, 2...Sensor element, 3...Element mounting part, 4...Shift register, 5...Shift register mounting part, 6...Wiring connection terminal , 7... Wiring connection part, 8... Pressure receiving part, 9... Flexible wiring board, 10... Support board, 11... Bent part, 12... Spacer, 13... For connection terminal. Ho Iya's 4-legged Shigeru Zenguchi is Ho 1 Heigo H Prisoner 20 6th AI! Figure 68 Figure 6A Bacterium 1 = Ho 1J Pressure Kansai 11 Hiroshi 4 Major Shiba Nesuko A Genkiri No. 7 A Side view of the worm Figure 78 Procedural amendment 1990 4 26th of the month

Claims (1)

[Claims] 1) A plurality of load detection elements each having a protruding pressure receiving part for receiving a load and a semiconductor strain gauge for detecting strain caused by the load from the pressure receiving part are arranged in an array. an element mounting portion of a flexible wiring board that is held in place and has wiring to the plurality of load detection elements formed thereon; and a circuit that extends from the flexible wiring board and processes signals from the plurality of load detection elements is mounted. a processing circuit mounting section; a bendable section provided at a connecting portion between the element mounting section and the processing circuit mounting section and capable of forming a step between both mounting sections; and a wiring connection part extending from a flexible wiring board and having a wiring terminal for connection to which wiring from the processing circuit mounting part can be connected to the outside, the processing circuit of the first pressure sensor The element mounting part of the second pressure sensor can be mounted on the mounting part by overlapping the element mounting part of the second pressure sensor, and in the mounted state, the element mounting part of the first pressure sensor and the mounting part of the second pressure sensor are bent. A pressure sensor characterized in that the pressure sensor is arranged in series on the same plane via a portion. 2) The pressure sensor according to claim 1, wherein the flexible wiring board has a connection terminal connectable to the connection wiring terminal of the wiring connection part in the attached state.