JPS6219746A - Device for producing or testing moisture sensitive element or the like - Google Patents

Abstract

PURPOSE:To shorten a processing time and to reduce the variance of characteristics by forming devices for cooling a placing board, heating the inside of a test tank and supplying steam into the tank respectively in the final production process for stabilizing the characteristics of a moisture sensitive element. CONSTITUTION:A plate 3 is arranged on the bottom of the test tank 1 and a cooling device 5 is arranged under the plate 3 to cool the plate 3 by fans 6. A heater 7 is fitted to the wall of the tank 1 to heat the inside of the tank 1. In addition, steam is blown out from a humidifier 8 and led from a blowing port 9 into the tank 1. Then, the moisture sensing element is set up on the plate 3 and the inside of the tank 1 is heated by the heater 7. On the other hand, stem is periodically supplied from the blowing port 9. At that time, the temperature of the moisture sensing element is set up lower than the temperature of the tank 1 and kept approximately at a dew point temperature to condense dews on the surface of the moisture sensing element. Since the dew condensation on the surface of the element is held for a long period, the stabilizing processing time of the element can be shortened and a change on the passage of time can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Summary of the Invention A test chamber including a sample mounting table, a cooling device for cooling the mounting table to a constant temperature, a heating device for heating the inside of the test chamber to a constant temperature, and a test chamber. Equipment for manufacturing or testing moisture sensing elements, etc., equipped with a humidifier to supply water vapor inside the device.

[Technical Field] The present invention is for testing other elements, substrates, etc. for manufacturing porous ceramic moisture sensing elements made of sintered bodies such as metal oxides and composite oxides.

In particular, the present invention relates to an apparatus for stabilizing the characteristics of moisture-sensitive elements, etc. in the final manufacturing process.

[Prior art] This type of moisture-sensing element consists of a pair of comb-tooth electrodes arranged so that the comb-teeth electrodes alternate at appropriate intervals, the electrodes covered with paste, and then baked. Manufactured by tying. The paste material contains lithium niobate (L
iNb03), lead oxide (pbo) and a catalyst. In the sintered state, the change in resistance value with respect to changes in humidity is extremely small, and it cannot be used as a humidity sensing element as it is. Therefore, in the final step of the manufacturing process.

Processing is performed to bring out the characteristics of a humidity-sensitive element: that the resistance value changes significantly in response to changes in external humidity. This process involves lithium (Ll) in the paste.
This is to draw out ions and make them freely movable.

Conventionally, methods such as a high temperature and high humidity leaving method and a dew condensation cycle method have been used for this treatment. As the name suggests, the former method involves leaving the moisture-sensitive element in a high-temperature, high-humidity environment for an extremely long period of time. In the latter method, the humidity in the constant temperature and humidity chamber is kept constant at high humidity, and the temperature is periodically raised and lowered. The heat capacity of the moisture sensitive element placed in the bath creates a difference between the temperature of the element and the ambient temperature. It utilizes the phenomenon that dew condenses on the surface of the device when the temperature of the device falls below the dew point temperature of the atmosphere.

According to the above-mentioned conventional method, there is a problem in that an extremely long treatment time is required before the characteristics of the moisture sensitive element become stable, that is, until desired characteristics are obtained. Furthermore, it is difficult to maintain uniformity of the conditions within the tank for such a long period of time.

As a result, the characteristics of the ultimately obtained moisture-sensitive elements also vary. Furthermore, in the environmental life test, the amount of change in characteristics over time was relatively large.

[Purpose of the Invention] The present invention provides a method for manufacturing a moisture-sensitive element, etc., which can shorten processing time, reduce variation in characteristics, and reduce rate of change in characteristics over time, particularly for processing in the final process, or The purpose is to provide equipment for testing other devices.

[Structure and Effects of the Invention] An apparatus for manufacturing or testing a moisture-sensitive element, etc. according to the present invention includes a test tank including a sample mounting table, a cooling device for cooling the mounting table to a constant temperature, and a cooling device for cooling the test tank to a constant temperature. It is characterized by being equipped with a heating device for heating the test chamber to a certain temperature, and a humidifier for supplying water vapor into the test chamber.

When this device is used in the final process of manufacturing a humidity sensitive element to stabilize its characteristics.

The temperature of the mounting table is slightly lower than the atmospheric temperature in the test chamber.
That is, the temperature is maintained near the dew point temperature of the same atmosphere. The humidifier repeatedly supplies water vapor into the test chamber at regular intervals. The water vapor blown into the test chamber settles within the chamber and condenses on the surface of the humidity sensing element. This condensation is maintained for a long time due to the difference between the mounting table temperature (approximately equal to the humidity sensing element temperature) and the dew point temperature of the temperature and humidity inside the test chamber, so the specific stabilization processing time for the humidity sensing element is shortened. , it is possible to reduce variations in characteristics and rate of change over time.

[Description of Embodiments] FIGS. 1 and 2 show embodiments of the present invention. The test chamber 1 is made of, for example, stainless steel, and the inside thereof is lined with cork material, plywood, or the like. A plate 3 is provided at the bottom of the test tank 1. On this plate 3, a large number of samples, such as moisture sensitive elements, are placed side by side. An air tank 4 is formed below this plate 3. Then, looking into the air tank 4, the cooling device 5
However, a fan 6 is also provided within each air tank 4. The air cooled by the cooling device 5 is stirred in the air tank 4 by the fan 6, so that the plate 3 is uniformly maintained at an arbitrary constant temperature. A side wall of the test tank 1 is provided with a heater 7 for heating the inside of the tank 1 and keeping the temperature constant, and an outlet 9 for discharging water vapor from a humidifier 8. Further, a ventilation hole 10 is provided below the heater 27 to communicate the test chamber 1 with the outside. The test chamber 1 is provided with an upper lid 2 made of acrylic resin.

When stabilizing the characteristics of a humidity sensitive element using such an apparatus, a large number of humidity sensitive elements to be treated are placed on the plate 3. Then, the inside of the test chamber 1 is slightly warmed by the heater 7, and the cooling device 5. The temperature of the plate 3 is maintained slightly lower than the temperature inside the test chamber 1 by the fan 6 and the air tank 4. The temperature of the plate 3 is set near the dew point temperature of the atmosphere inside the tank 1. Further, water vapor is periodically sent into the tank 1 from the humidifier 8 through its outlet 9 to humidify the inside of the tank 1. for example,
Plate temperature is 29℃, atmosphere temperature in tank 1 is 34℃
□, and control the humidifier 8 so that the atmospheric humidity in the tank 1 is about 70 to 80%. The humidification cycle is
Steam blows out humidifier 8 on) 4 seconds, humidifier 8 off 20
~30 seconds (when the inner wall of tank 1 is lined with cork), or about 5 seconds with the humidifier on and 40 seconds off (when the inner wall of tank 1 is made of stainless steel).

The water vapor blown into the test tank 1 from the humidifier 8 evaporates, but a portion of it gradually settles in the tank 1 due to gravity and is evenly deposited on the humidity sensing element on the plate 3. This dew condensation on the surface of the humidity sensing element is maintained to some extent by the difference between the temperature of the plate 3 and the atmospheric temperature within the tank 1. By repeating such a humidifying operation many times, stabilization of the characteristics of the moisture sensitive element is promoted.

FIG. 3 shows a comparative example of processing times when characteristics stabilization processing of a moisture sensitive element is performed using a conventional method (condensation cycle method) and a method using the apparatus according to the present invention. As the stabilization process is performed, the resistance value of the humidity sensing element (at a certain humidity, 60% in this example) gradually decreases and stabilizes at a certain constant value. The stabilization curve shown as a dashed line is for the conventional method, and the stabilization curve for the method using the device of the invention is shown as a solid line. It can be seen that the method using the apparatus according to the present invention significantly shortens the processing time (reduced to 1/7).

Tables 1 to 3 show the environmental life test results.

Table 1 shows the results of the high temperature and high humidity storage test.

The sample (humidity sensitive element) was left in an environment with a temperature of 60° C. and a humidity of 95% for 1000 hours. "Conventional" is the result of the sample processed by the conventional method described above, and "New" is the standard deviation of the sample processed by the method described above using the apparatus of the present invention.

Table 2 shows the results of the high temperature storage test. 8 samples
It was left in an environment at 5°C for too long.

Table 3 shows the tobacco test results. 3 bottles a day (morning,
A total of 27 cigarettes (one each for lunch and dinner) were burned for 9 days in a 27A container containing samples. Measurements were taken 24 hours after removing the sample from the container.

From the test results shown in Table 1, Table 2, and Table 3, it can be seen that the changes over time in the characteristics of the moisture sensitive element are reduced, and the variation in characteristics is also reduced.

The apparatus of this invention can be used not only for manufacturing moisture sensitive elements.

It can also be applied to dew condensation tests on ceramic substrates, hybrid IC substrates, etc.

[Brief Description of the Drawings] Figures 1 and 2 show embodiments of the present invention.
FIG. 1 is a side sectional view, and FIG. 2 is a front sectional view. FIG. 3 is a graph showing a characteristic stabilization curve of the humidity sensitive element. 1... Test tank, 3... Plate (mounting stand). 4...Air tank, 5...Cooling device, 6...
fan. 7... Heater, 8... Humidifier. 9...Steam outlet. Patent applicant: Tateishi Electric Co., Ltd. Agent: Kenji Ushiku and one other person Figure 1: FIJ

Claims (1)

[Scope of Claims] A test tank including a sample mounting table, a cooling device for cooling the mounting table to a constant temperature, a heating device for heating the inside of the test tank to a constant temperature, and a system for introducing water vapor into the test tank. Equipment for manufacturing or testing moisture-sensitive elements, etc., equipped with a humidifier for supplying moisture.