JPH0315750A - Gas sensor - Google Patents

Abstract

PURPOSE:To provide the gas sensor which is adequate for thickness reduction and can be easily mounted by providing a substrate having a recessed part, electrodes provided along the surface of the substrate and a detecting element which is disposed in the recessed part of the substrate and is connected to the electrodes. CONSTITUTION:The detecting element 7 is disposed in the recessed part 5 of the substrate 1 and can be connected to internal terminals 6a of the electrodes 6 and, therefore, the thickness over the entire part of the gas sensor can be reduced. Since the electrodes 6 are planar, the larger area for mounting the terminals 6a can be taken. The connection of lead wires 8 of the element 7 to the terminals 6a is, therefore, facilitated. Further, the mounting of the electrodes 6 to the substrate 1 is easy and the easy change of the number and position of the terminals 6a are possible according to the kinds and shapes of the element 7, as the electrodes 6 are formed by the metallization, etc., of tungsten. The position of the external terminals 6b to desired positions is possible as well.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a gas sensor used to prevent accidents caused by gas leaks or incomplete combustion of gas, and which is particularly suitable for thinning and is easy to install. This invention relates to a gas sensor that can perform

(Prior Art) As shown in FIG. 8, a conventional gas sensor includes a substrate 1, a plurality of pin-shaped electrodes 6 extending perpendicularly to and through the surface of the substrate 1, and a wire mesh covering the substrate 1. 9, the detection element 7 is arranged in a space surrounded by the substrate 1 and the wire mesh 9,
A lead wire 8 of the detection element 7 is connected to an internal terminal of each electrode 6. With this configuration, the gas to be detected is introduced into the gas sensor through the wire mesh 9, and the gas to be detected is brought into sufficient contact with the detection element 7, thereby obtaining good detection results.

(Problems to be Solved by the Invention) However, in the conventional gas sensor described above, since the electrode 6 extends perpendicularly to the surface of the substrate l, a height corresponding to this length is required, and the overall thickness of the sensor is reduced. There was a problem that it could not be done. This becomes an obstacle to making the entire device smaller and thinner, especially when the gas sensor is used together with recent electronic components that have become significantly smaller and thinner. Also,
Because the electrode 6 is pin-shaped and has a small surface area, it is not easy to connect the lead wire 8 of the detection element 7 to the internal terminal of the electrode 6, or because the electrode 6 penetrates the substrate 1 and is fixed thereto. Furthermore, there are also drawbacks in terms of installation, such as the inability to appropriately and easily change the number and position of internal terminals depending on the type and shape of the detection element 7, etc.

The present invention was made to solve these problems, and an object of the present invention is to provide a gas sensor that is suitable for thinning and can be easily installed.

(Means for Solving the Problems) In order to achieve the above object, the gas sensor of the present invention includes a substrate having a recess, a plate-shaped electrode provided along the surface of the substrate, and a gas sensor disposed in the recess of the substrate. and a detection element connected to the electrode.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

Figures IA to 1C show a gas sensor according to a first embodiment of the invention. 1 in these figures is a substrate, and the substrate 1 is constructed by laminating and firing square first to third sheets 2 to 4 made of, for example, ceramic green sheets.

The second sheet 3 is provided with a rectangular center hole 3a, and the third sheet 4 is provided with a substantially square center hole 4a that is larger than this center hole 3a. A recess 5 of 1 is formed.

Four plate-shaped electrodes 6 made of, for example, tungsten and spaced apart from each other extend from both ends of the two steps formed between the second sheet 3 and the third sheet 4. It extends between the first seats 3 and 4 and along the outer surfaces of the second and first seats 3 and 2 to the lower surface of the first seat 2. An internal terminal 6a and an external terminal 6b are formed at the inner end and outer end of each electrode 6, respectively, by metallizing, for example, tungsten and then sequentially applying nickel plating and gold plating.

Inside the recess 5 of the substrate 1 is a detection element 7 made of a well-known material.
are arranged, and the lead wire 8 is connected to the internal terminal 6a of each electrode 6.
is connected to. Further, a wire mesh 9 made of stainless steel, for example, is provided to cover the third sheet 4 of the substrate l.

This wire mesh 9 plays the role of explosion protection and introduces the gas to be detected into the sensor through it.

According to the above configuration, the detection element 7 is arranged in the recess 5 of the substrate l, and can be connected to the internal terminal 6a of the electrode 6 facing the recess 5, so that the overall thickness of the gas sensor can be reduced compared to the conventional one. I can do it. Further, since the electrode 6 is plate-shaped, the mounting area of the internal terminal 6a can be increased, and therefore, the lead wire 8 of the detection element 7 can be easily connected to the internal terminal 6a. Furthermore, since the electrode 6 is formed by metallizing tungsten or the like, it is easy to attach the electrode 6 to the substrate l, and the number and position of the internal terminals 6a can be adjusted appropriately depending on the type and shape of the detection element 7. and can be easily changed. For the same reason, the external terminal 6b can be placed at a desired position. 2 to 4 show the external terminal 6b
An example is shown in which the external terminals 6b and 6b are arranged at different positions.
are arranged on the side, top, and bottom surfaces of the gas sensor, respectively, and are connected to lead wires 10 for connection to a circuit (not shown) or the like.

The second embodiment of the present invention shown in FIG.
The only difference is that a central hole 2a similar to the central hole 3a of the gas sensor is provided, and wire mesh 9 is provided on both the upper and lower surfaces of the gas sensor.
With such a configuration, the gas to be detected can be introduced from both the upper and lower sides of the gas sensor through the wire mesh 9.

Figures 6A to 6C show a third embodiment of the present invention. In this embodiment, a plurality of gas sensors are arranged side by side, whereas in the above-mentioned embodiments there is only one gas sensor. That is, the first sheet 2 is made common, and the second and third sheets 3 and 4 are placed on top of it.
A plurality of (two in the drawings) recesses 5 are provided in the substrate 1 with the same configuration as in the first embodiment, and each recess 5 is arranged at a predetermined interval.
Detecting elements 7 are respectively disposed inside, and each recess 5 is further covered with a common wire mesh 9. As is well known, the detection range of gas sensors is relatively narrow, and in order to increase the detection accuracy, multiple gas sensors with different detection ranges are used, or gas sensors and other types of sensors such as humidity sensors, temperature sensors, etc. This embodiment can be advantageously used in such cases.

Figures 7A to 7C show a fourth embodiment of the present invention. In this embodiment, the substrate 1 is integrally constructed from a printed laminated portion l1 and a green sheet laminated portion 12 disposed on the printed laminated portion I1 to form a ceramic multilayer wiring board. A plurality of recesses 5 are provided in l2, a plurality of detection elements 7 are arranged in some of the plurality of recesses 5, and an IC for signal processing and data storage from the detection elements 7 is placed in the remaining recesses 5.
A chip 13 and chip components 14 such as resistors and capacitors are arranged. Each detection element 7, IC chip 13
, the wiring between the chip component 14 and the clip terminal 15 is as follows:
This is done by the green sheet stacking section l2 or by the green sheet stacking section l2 and the printing stacking section 11.

The recess 5 in which the detection element 7 is arranged is covered with a common wire mesh 9, and the recess 5 in which the IC chip 13 and chip components 14 are arranged is sealed with a common cover 16 made of metal, ceramic, etc. . With such a configuration, not only the plurality of gas sensors but also the IC chips and chip components used therewith can be arranged on an integrated ceramic multilayer wiring board, and therefore, they can be made thinner and smaller as a whole. .

(Effects of the Invention) As described in detail above, the gas sensor of the present invention has the advantage of being suitable for thinning and being easily mounted.

[Brief explanation of drawings]

FIGS. IA to 1C are a sectional view, a top view, and a bottom view of a gas sensor showing a first embodiment of the present invention, and FIGS.
The figure shows an example in which the external terminals 6b are arranged at different positions, FIG. 5 is a sectional view of a gas sensor showing a second embodiment of the present invention, and FIGS. Figures similar to Figures IA to IC, respectively, showing embodiments;
7A to 7C show a fourth embodiment of the present invention,
A perspective view, a sectional view, a partially detailed sectional view, and FIG. 8 are perspective views showing a conventional gas sensor. 1...Substrate, 5...Recess, 6...Electrode, 7...Detection element. Flute 2 Figure 4 Figure 6A

Claims (1)

[Claims] A gas sensor comprising: a substrate having a recess; a plate-shaped electrode provided along the surface of the substrate; and a detection element disposed in the recess of the substrate and connected to the electrode.