JPS5856110B2 - Gaibufunikikenchisouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an external atmosphere detection device in which an external atmosphere detection section for detecting gas, humidity, etc. is formed on the upper surface of a heat-resistant insulating substrate such as ceramic.

A conductive pattern for connecting an electrode for external atmosphere detection and a lead wire is formed on a heat-resistant insulating substrate, and when this conductive pattern is made of a metal that is relatively easily oxidized, such as tungsten, the pattern is If even some portions are exposed, the electric resistance value increases due to oxidation due to contact with air during high-temperature processing during manufacturing, which has the disadvantage of degrading device characteristics.

Furthermore, even if such oxidation of a conductive pattern occurs in a very localized area, the volume expansion caused by the oxidation causes the heat-resistant insulating layer covering the pattern to be locally peeled off from the heat-resistant insulating substrate. Air flows in and promotes oxidation,
This has the disadvantage of further accelerating the deterioration of device characteristics.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide an external atmosphere detection device that does not cause deterioration of device characteristics due to oxidation of a conductive pattern.

In order to achieve the above object, the present invention has a pair of electrodes and a conductive pattern for leads for each electrode set on the upper surface of a heat-resistant insulating substrate, and a lead wire for external atmosphere detection is provided at the end of this conductive pattern. The upper surface of the substrate is covered with a heat-resistant insulating layer, leaving the electrode and lead wire through holes, and the ends of the conductive pattern are set in the insulating substrate within the area covered with this insulating layer. It is characterized in that it is electrically connected to the lead wire via a conductive portion.

According to this invention, the conductive pattern is not exposed to the outside air while being connected to the lead wire, so even if the conductive pattern is made of a material that is easily oxidized, the pattern will not be oxidized during high-temperature processing. .

Therefore, it is possible to obtain a device that does not suffer from characteristic deterioration such as an increase in electrical resistance due to oxidation.

FIG. 1 is a partially cutaway perspective view showing an example of an external atmosphere detection device according to the present invention, in which 1 is a heat-resistant insulating substrate such as a ceramic substrate, and upper and lower substrates 2 are made of heat-resistant ceramic raw sheets, for example. A heating resistor 4 is formed on either the upper or lower side of the opposing surface of the substrate 4 by a thick film method using screen printing.

At the four corners of the lower substrate 3 are through-holes 9°, 10. through which the shaft portions of the heating resistor lead wires 5, 6 and external atmosphere detection lead wires 7, 8 are inserted, and into which the respective heads 13 are engaged. 11.12
(See Figures 2 and 3).

The upper substrate 2 is formed in the same shape as the lower substrate 3, and has through holes 14 in its four corners into which the heads 13 of the lead wires 5 to 8 are inserted.

18 and 19 are tungsten (Tungsten) shaped like a T-shape formed on the upper surface of the upper substrate 2 by vapor deposition or thick film method.
A conductive pattern for leads made of W), nickel (Ni), etc., and a detection electrode 20.
21 is formed.

If the pattern 18.19 is tungsten, the electrode 20.21 is set thereon by plating non-oxidizing material such as Au on Au or Ni.

Through holes 32 and 33 are formed in the upper substrate 2 at the ends 18a and 19a of the conductive patterns 18 and 19 (
3), a conductive pattern 34 for leads is formed on either the upper or lower side of the opposing surfaces of the upper and lower substrates 2, 3, spanning the through holes 32, 33 and the detection lead wire through holes 11, 12.
．． 35 is formed by a thick film method using screen printing when forming the heating resistor 4.

The upper and lower substrates 2 and 3 are overlapped, the through holes 32 and 33 are filled with shorting conductors 36 and 37, and the conductive patterns 18, 34, 19 and 35 for both leads are connected, respectively.

Further, on the upper surface of the upper substrate 2, a heat-resistant insulating layer 38 made of a kneaded material of raw ceramic powder is applied using a thick film method using screen printing, leaving the areas above the electrodes 20.21 and lead wire through holes 9-12. Ru.

Thereafter, with the upper and lower substrates 2.3 superimposed, the substrate 1 includes the heating resistor 4, the conductive patterns for leads 18, 19, 34,
35, conductors 36, 37, electrodes 20, 21, and heat-resistant insulating layer 38 are fired integrally.

The paste for forming the heating resistor 4, the conductive patterns 18, 19, 34, 35, and the short-circuiting conductor 36, 37 is a paste that is optimal in view of the sintering conditions of the raw ceramic sheet, such as Tank Ten (W). ), molbdenum (M o
), resistor ink containing compositions such as molybdenum-mangaso alloy (Mo-Mn), conductor ink, or glass powder containing glass powder to improve adhesion with ceramics. By simultaneously firing the sheets at an appropriate temperature, the heating resistor 4, the conductive patterns 18, 19°34.35, and the shorting conductor 36.37 are formed on the ceramic upper and lower substrates 2, 3 and the heat-resistant insulating layer 38. installed between each other.

As raw ceramics for forming the upper and lower substrates 2, 3 and the insulating layer 38, for example, alumina ceramics or berria ceramics are used.

Each lead wire 5 to 8 is inserted into each through hole drilled in the substrates 2 and 3 from above the substrate 1 in order to be electrically connected and fixed to both ends of the heating resistor 4 and the lead conductive patterns 34 and 35. They are set to penetrate vertically, and are electrically connected and fixed using soldering materials 22 such as silver soldering.

The heads 13 of each of the lead wires 5 to 8 are fitted into the through holes 14, and the soldering material 22, such as silver solder, is fixed, and then the electrodes 20.21 are placed on the upper surface of the upper substrate 2, covering the electrodes 20.21. V2O5,
An external atmosphere sensing portion 23 made of a metal oxide semiconductor such as ZnO is deposited by vapor deposition or thick film printing.

As is clear from the above configuration, the conductive patterns 18 and 19
The ends 18a and 19a of the short-circuiting conductor 3 are embedded in the insulating substrate 1 in the area covered with the insulating layer 38.
The conductive pattern 18 is electrically connected to the lead wires 7 and 8 through the conductive pattern 6.37 and the conductive pattern 34.35.
．． The conductive patterns 34 and 35 are not exposed to the outside air while they are connected to the lead wires 7 and 8, and the conductive patterns 34 and 35 are covered with the brazing material 22 and are not exposed to the outside air. , 19, 34° 35 are made of an easily oxidized material such as tungsten (W), they will not be oxidized by high temperature treatment during manufacturing or heat generated by the heating resistor 4 during use. Accordingly, deterioration of device characteristics can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a detection device according to the present invention, and FIGS. 2 and 3 are cross-sectional views taken along the line ■--■ and mm; gland in FIG. 1. DESCRIPTION OF SYMBOLS 1...Heat-resistant insulating board, 2...Upper board, 3...Lower board, 7, 8...Detection lead wire, 11,12... ...Lead wire penetrator L
18, 19... Conductive pattern for lead, 20,
21... Electrode, 34, 35... Conductive pattern, 36, 37... Conductor, 38...
...Heat-resistant insulating layer, 23...External atmosphere detection section.

Claims (1)

[Claims] 1. A heat-resistant insulating substrate formed by bonding and sintering an upper substrate and a lower substrate, a lead wire through-hole formed vertically through the heat-resistant insulating substrate at a predetermined interval, and this lead wire through-hole. an external atmosphere detection lead wire inserted and fixed to the oxidizing conductive lead wire interposed between the joint surface of the upper and lower substrates of the heat-resistant insulating substrate and electrically connected to the detection lead wire; the pattern, and other oxidizing conductive patterns for leads deposited at predetermined intervals on the upper surface of the upper substrate;
A conductor that electrically connects both of the lead conductive patterns located on the upper and lower surfaces of the upper substrate, a non-oxidizing electrode that is adhered to the lead conductive pattern on the upper surface of the upper substrate, and a non-oxidizing electrode and the lead. A heat-resistant insulating substrate layer is deposited on the upper surface of the upper substrate leaving a wire through hole and covering at least a conductive pattern for leads; An external atmosphere detection device characterized by comprising a connected external atmosphere detection section.