JPS6015003B2 - Manufacturing method of pyroelectric infrared detection element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of a lightning-type infrared detection element having good sensitivity.

A conventional lightning-type infrared detection element is shown in FIG.

In the figure, reference numeral 1 denotes a planar infrared detection element, in which electrodes 2 and 3 are formed on both planes of a strongly electrostatic ceramic. A blackened film 4 is formed on the electrode 3 side, that is, on the light receiving side. Element 1 is placed on base 5 and fixed with conductive paste or a mixture of conductive paste and resin, etc., and electrodes 2 and 3 are connected to external terminals 6 by lead wires 8 and 9.
, 7. The single hole serves to prevent heat sinking from the element 1 to the base 5.

In order to increase the sensitivity, such a structure is generally placed at the focal point of the condenser, as shown in FIG.

In the figure, 11 is a container, and a concave mirror 12 is formed inside. 13 is the infrared detection element shown in FIG.
It is placed at the focal point of the concave mirror 12.

Terminals 14 and 15 support and fix the element 13 to the container 11.

16 is a window formed at the entrance of the container 11.

However, when a conventional infrared detection element is placed in a condenser, the following drawbacks are observed.

That is, in a reflective infrared detection device using a concave mirror, the reflected light from the vicinity of the outer periphery of the concave mirror 12 is quite oblique, and if the infrared detection element has a planar light-receiving surface as shown in FIG. However, the energy density of the infrared rays hitting the element was quite small, and the sensitivity was not substantially increased.

In order to eliminate this drawback, the radius of curvature of the concave mirror can be increased, but this increases the size of the entire device, making it unsuitable for consumer use such as home use.

The inventor studied the above-mentioned problems and found that the use of an infrared detection element having a convex light-receiving surface has the following advantages.

In other words, when the above-mentioned infrared detection element is placed at the focal point of the condenser, since it has a convex curved surface on the light-receiving surface side, the reflected light that gathers at the Kurarasu point is directed at an angle close to perpendicular to the curved surface. The incident energy density is larger than that of conventional devices, and the sensor has excellent sensitivity.

Furthermore, there is no need to use a concave mirror with a large radius of curvature in order to increase sensitivity as in the conventional method, and there is an advantage that the overall shape of the condenser can be made smaller. The present invention has been made from this point of view, and it is an object of the present invention to provide a method for easily manufacturing an infrared detection element having good sensitivity.

That is, the gist of the present invention is that, in manufacturing a pyroelectric infrared detection element having a curved main surface, an unfired or fired ferroelectric ceramic molded plate is placed on a molding table having a curved surface. It is characterized in that it is placed on a curved surface and fired at a temperature higher than the dawning temperature of the strongly electrostatic ceramic molded plate and at which the molded plate obtained by phosphorization softens. This invention will be described in detail below according to one embodiment.

Pb (Zr, Ti) 03-based strong electric material powder prepared in advance is heated together with a binder, and then subjected to dehydration, drying, and granulation steps, and then molded using pressure molding, extrusion molding, or the doctor blade method. An unfired strongly electrostatic ceramic molded plate was created by molding it into a flat shape. Next, as shown in FIG. 3, a molding table 21 made of porcelain such as alumina, zirconia, steatite, etc. has a convex curved surface 22 corresponding to the curved surface of the hard-type infrared detection element to be obtained.
The unfired strongly electrostatic ceramic molded plate 23 obtained as described above is placed on top of the molded plate at a temperature higher than the sintering temperature at which the molded plate is normally sintered, and the molded plate obtained by sintering becomes soft. Fired at a serious temperature.

Through this firing process, the molded plate was softened and curved by its own gravity, yielding a strong tortoise-like ceramic having a curved main surface. After this, C is applied to both main surfaces of the ferroelectric ceramic.
Electrodes of Ag, Au, etc. are formed by vapor deposition, plating, etc., and then D.
Polarization treatment was performed by applying a voltage approximately on the V/side of the C string.

Subsequently, heat treatment was performed to stabilize the polarization state, and a blackened film was formed on the surface to increase infrared absorption efficiency. FIG. 4 shows an example of a device assembled using the infrared detection element obtained by the method described above.

In FIG. 4, numeral 31 is a strongly electrostatic ceramic made of Pb(Ti,Zr)03-based porcelain, and the protruding surface of the curved two-dimensional surface is the light-receiving surface. Electrodes 32 and 33 are formed on both surfaces, respectively. 34 is a blackened film, which is formed on the electrode 33 on the light-receiving surface side.

Reference numeral 35 denotes a base on which the electromagnetic ceramic 31 is fixed, and electrodes 32 and 33 of the electromagnetic ceramic 31 are electrically connected to terminals 36 and 37 of the base 35 by lead wires 38 and 39. .

The hole 40' formed in the base 35 prevents heat sinking from the electrostatic ceramic 31 to the base 35.

In the above embodiment, Pb (Zr, Ti) is used as a strong electrolyte.
Although we have explained the 03 series porcelain, we also have mother Ti03 series porcelain, PbTi03 series porcelain, LITa03 series porcelain, SB
Of course, a strongly electrolytic material such as N-based porcelain can be used.

Furthermore, in addition to the unfired strong electrostatic ceramic molded plate, a fired strong electrostatic ceramic molded plate may be used.

In this case, there is an effect that cracks that occur when the fired molded plate is polished into a thin plate shape can be removed during firing on the molding table. Furthermore, although a molding table with a convex curved surface was used for molding the strongly electrolytic ceramic molded plate, a molding table with a concave curved surface may also be used.

In addition to the above-mentioned molding table, any molding table may be used as long as it does not react with the strongly electrostatic ceramic molded plate. Further, the curvature of the curved surface may be determined depending on the application, and the curved shape may be arbitrary.

For example, the shape of the curved surface includes a bowl-shaped curved surface.
As described above, according to the present invention, a fired or fired foghorn ceramic molding plate is placed on the curved surface of a molding table having a curved surface, and the temperature is higher than the dawning temperature of the strong electromagnetic ceramic molding plate. , and the molded plate obtained by sintering is fired at a temperature so high that it softens, and there is no risk of cracking of the ceramic that occurs when polishing a strongly electrolytic ceramic to form a curved surface. This method has the advantage that a condensation type infrared detecting element having a constant curvature can be manufactured by an extremely simple method.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional pyroelectric infrared detection element, Fig. 2 is a sectional view of a device using the pyroelectric infrared detection element of Fig. 1, and Fig. 3 is an explanation showing part of this method. The plan view and FIG. 4 are cross-sectional views of a tortoise-type infrared detecting element obtained by the method of the present invention. 21... Molding table, 22... Curved surface, 23...
...Ferroelectric ceramic molded plate. *1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. When manufacturing a pyroelectric infrared detection element having a curved main surface, an unfired or fired ferroelectric ceramic molded plate is placed on the curved surface of a molding table having a curved surface, and the ferroelectric ceramic molding is performed. A method for manufacturing a pyroelectric infrared detecting element, characterized in that firing is performed at a temperature higher than the sintering temperature of the plate and at which the molded plate obtained by sintering begins to soften.