JP2002139416A - Corrosion sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corrosion sensor which enables accurate measurement of the degree of corrosion of metal this films exposed to an environment subjected to the measurement in a type for evaluating the corrosivity of the environment. SOLUTION: In the corrosion sensor comprising metal this films formed on a transparent base plate by varying the thickness thereof, a reference metal this film with a covered film surface is provided and with the metal color thereof as reference, difference in color between the thin film metal and any corrosion product thereof is utilized to determine the degree of corrosion of the metal this film. The arrangement of the reference metal this film covered with a cover material enables correctly judging of the location at which the metal this films varied in thickness change and present the color of the corrosion product, namely, the degree of corrosion of the metal this films.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion sensor for evaluating the corrosiveness of an environment, and more particularly to a corrosion sensor for evaluating the corrosiveness of a trace gas in an atmospheric environment, which is a corrosive factor of electronic components.

[0002]

2. Description of the Related Art Many electronic devices are installed and used in a controlled environment. However, when used in a place where there are many people, corrosive gas may be mixed.
If the humidity is not controlled, condensation may form. The corrosive gas of the components and the moisture in the air cause the corrosion of the equipment parts, which causes a problem that the corrosion reliability is reduced. In the future, considering that the use of electronic devices will expand to general offices and that equipment parts will be lighter, thinner and smaller, even corrosion damage, which was not a problem in the past, will cause deterioration of component characteristics and failure. There is fear.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 10-90165, an atmospheric corrosion sensor comprising a metal thin film formed on a transparent substrate by changing the film thickness has been devised. After leaving this sensor in the environment to be measured for a predetermined period, when the metal thin film is observed through the transparent substrate from the non-deposition side, the thin metal thin film is completely changed into a corrosion product, and the corrosion product The color has changed. On the other hand, in the case of a thick metal thin film, the corrosion product does not progress to the interface on the substrate side, and thus the color of the metal remains the same. As described above, the corrosion product generated on the metal thin film is measured by utilizing the difference in color between the metal and the corrosion product, and the corrosiveness of the measured environment is evaluated.

[0004]

In the above prior art, the amount of corrosion of the metal thin film is determined by visually determining the difference between the color of the thin film metal and the color of the corrosion product through the transparent substrate. That is, based on the metal color of the thin film having a large thickness, it is determined to which thickness the thin film has changed to the color of the corrosion product. When a part of the thin film in the thickness direction is changed to a corrosion product due to exposure to the environment to be measured, when the metal thin film is observed through the transparent substrate, the metal thin film is affected by the color of the corrosion product and the initial metal color. Shows neutral colors of corrosion products. Therefore, when the metal color of the metal thin film exposed to the environment to be measured is used as a reference, there is a problem that a portion where the color of the corrosion product changes is misidentified.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a corrosion sensor comprising a thin metal film formed on a transparent substrate with a variable thickness by newly providing a reference metal thin film covering the film-forming surface. This is achieved by determining the amount of corrosion of the metal thin film using the fact that the color of the thin film metal and the corrosion product thereof are different based on the color.

Another object of the present invention is to provide a corrosion sensor comprising a metal thin film formed on a transparent substrate with a variable thickness.
This is achieved by coating a part of the metal thin film with a coating material to provide a portion that does not corrode. Since it does not change over time based on the metal color at the location coated with the coating material, it is possible to accurately determine whether the color of the thin film at the uncoated exposed location is a metal color or a color of a corrosion product. You can judge.

[0007]

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

FIG. 7 is a plan view showing a conventional atmospheric corrosion sensor, and FIG. 8 is a sectional view taken along line AA. Metal thin films 1 having different thicknesses are formed on a transparent substrate 2 by bonding, bonding, vapor deposition, sputtering, plating, or the like. As the material of the thin film, for example, the corrosion by hydrogen sulfide gas can be evaluated by using silver, and the corrosion by chlorine gas can be evaluated by using aluminum. Corrosion of the thin film proceeds from the side exposed to the environment. FIG. 9 is a plan view of the atmospheric corrosion sensor after exposure to the environment to be measured, and FIG. As can be seen from the cross-sectional view of FIG. 10, the metal thin films 1 at t1 and t2 all become corrosion products 12, and the exposed thin film is corroded with the thicker metal thin film 1 at t3 and t4, but extends to the interface on the substrate side. Corrosion has not progressed. When observing the metal thin film 1 through the transparent substrate 2, the thin films at t1 and t2 have changed to the color of the corrosion product 12, but the thin films at t3 and t4 have the color of the metal. This indicates that the corrosion thickness is between t2 and t3. By reducing the change in thickness of the thin film,
Corrosion thickness can be measured accurately.

Here, when determining whether the metal thin film 1 is a metal color or the color of the corrosion product 21, the metal color of the metal thin film 1 having a large film thickness is used as a reference. As shown in FIG. 10, even in the metal thin film 1 having the largest film thickness, the corrosion product 12 is formed on the film forming surface side. Therefore, when observed from the non-film-forming surface side, the color of the metal thin film 1 shows an intermediate color between the initial metal color and the corrosion product 12. Therefore, even when the metal thin film 1 is not completely corroded when observed from the non-film-forming surface side, the metal thin film 1 is observed as discolored, and the place where the color of the corrosion product changes is misidentified. There is.

As a first embodiment, FIG. 1 is a plan view showing a corrosion sensor, FIG. 2 is a sectional view taken along line AA, and FIG. 3 is a sectional view taken along line BB. As shown in the AA sectional view of FIG. 2, metal thin films 1 having different thicknesses are formed on a transparent substrate 2. 3, the metal thin film 12 is partially covered with the covering material 3 from the film forming surface side. When the corrosion sensor is exposed to the environment to be measured, FIG. 4 is a plan view of the corrosion sensor, FIG. 5 is a cross-sectional view of the metal thin film without a coating material taken along line AA, and FIG. FIG. By coating with the coating material 3, corrosion of the metal thin film 1 is prevented. The amount of corrosion of the metal thin film 1 can be obtained by utilizing the fact that the colors of the thin film metal 1 and the corrosion products 12 thereof are different based on the metal color of the metal thin film 1 there.

As the coating material 3, a substance which does not transmit or hardly transmits a corrosive substance or moisture existing in the measurement environment is preferable. Further, as the coating material, a transparent substance is preferable. This is because, in the metal thin film 1 having a small film thickness, the color of the metal thin film 1 is affected by the color of the coating material 3 on the back side, and there is a possibility that a portion where the color of the corrosion product 12 changes may be mistaken. .

As a second embodiment of the present invention, FIG. 11 is a plan view showing a corrosion sensor, and FIG. 12 is a sectional view taken along line AA. Metal thin films 1 having different thicknesses are formed on a transparent substrate 2. Further, a metal thin film 1 is newly prepared, and a coating material 3 is coated on the entire surface of the film. By coating with the coating material 3, corrosion of the metal thin film 1 is prevented. The amount of corrosion of the metal thin film can be obtained by utilizing the fact that the colors of the thin film metal and its corrosion products are different based on the metal color of the metal thin film there. Further, as shown in FIG. 13, by disposing the reference metal thin film covered with the coating material 3, the portion where the metal thin film of each film thickness changes into the color of the corrosion product, that is, the amount of corrosion of the metal thin film can be accurately determined. You can judge.

[0013] Even when a continuously changing metal thin film is used, a metal thin film coated with a coating material may be newly provided, or a part of the metal thin film exposed to the environment to be measured may be coated with the coating material. By indicating the reference value of the metal color, it is possible to accurately determine the location where the metal thin film changes to the color of the corrosion product, that is, the amount of corrosion of the metal thin film.

[0014]

According to the present invention, in a corrosion sensor comprising a metal thin film formed on a transparent substrate by changing the film thickness, a reference metal thin film covering the film formation surface is provided, and the metal color is used as a reference. By doing so, it is possible to provide a corrosion sensor that can accurately determine the location where the metal thin film changes to the color of the corrosion product, that is, the amount of corrosion of the metal thin film.

[Brief description of the drawings]

FIG. 1 is a plan view showing a corrosion sensor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of the corrosion sensor of FIG. 1;

FIG. 3 is a sectional view of the corrosion sensor taken along line BB of FIG. 1;

FIG. 4 is a plan view of the corrosion sensor after being exposed to an environment to be measured.

FIG. 5 is a cross-sectional view of the corrosion sensor of FIG. 4 taken along line AA after being exposed to an environment to be measured.

FIG. 6 is a cross-sectional view of the corrosion sensor of FIG. 4 taken along line BB after exposure to an environment to be measured.

FIG. 7 is a plan view of a conventional corrosion sensor.

FIG. 8 is a sectional view of the conventional corrosion sensor taken along line AA of FIG. 7;

FIG. 9 is a plan view of a conventional corrosion sensor after being exposed to an environment to be measured.

FIG. 10 is a cross-sectional view of the corrosion sensor of FIG. 9 taken along the line AA after being exposed to an environment to be measured.

FIG. 11 is a plan view of a corrosion sensor according to another embodiment of the present invention.

FIG. 12 is a sectional view taken along line AA of the corrosion sensor of FIG. 11;

FIG. 13 is a plan view of a corrosion sensor according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Metal thin film 12 ... Corrosion product 2 ... Transparent substrate 3 ... Coating

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyoshi Matsui 1st Horiyamashita, Hadano-shi, Kanagawa Prefecture In-house Enterprise Server Division, Hitachi Ltd. F term in information technology (reference) 2G050 AA01 BA05 CA01 EB07 2G055 AA05 AA07 BA12 CA02 CA20 DA08 EA07 FA02

Claims (2)

[Claims] 1. A corrosion sensor comprising a metal thin film formed on a transparent substrate with a variable thickness, wherein a reference metal thin film covering a film formation surface is provided. 2. A corrosion sensor comprising a thin metal film formed on a transparent substrate by changing the thickness thereof, wherein at least one of the thin metal films is partially covered with a part of the metal thin film around the thin film. A corrosion sensor having an area in communication with an atmosphere.