JPH0253741B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field) This invention relates to a method for testing the pressure resistance, temperature resistance, and humidity resistance of various precision equipment and their parts, such as electronic equipment, communication equipment, and photographic equipment. This invention relates to a method for controlling the temperature and pressure inside a container that houses a test object in a pressurized environmental tester.

(Background Art) As an environmental resistance tester for performing accelerated tests on various precision instruments and their parts, a structure as shown in FIG. 1, for example, is known. The tester shown in Fig. 1 has a horizontal bottomed cylinder shape, and an inner cylinder 3 with one end open is provided inside an outer cylinder 2 whose open end can be sealed with a lid 1, and the outer cylinder 2 is heated from the outside. A heater 4 and a heater 5 for evaporating water stored in the lower part of the outer cylinder are installed, and a fan 7 placed in a vent 6 opened at the back of the inner cylinder 3 is connected to a magnetic force consisting of an internal magnetic coupling piece 8a and an external magnetic coupling piece 8b. It is configured to be driven by a motor 9 from outside the outer cylinder via a coupling, and a heater 10 is also provided near the fan 7. Usually, a plurality of test objects 11 such as semiconductors are placed on a stand 12 inside the inner tube 3, and the vapor atmosphere inside the tester is made unsaturated by controlling the amount of electricity supplied to the heaters 4, 5, and 10. , saturation, and heating, and perform accelerated tests on the test object. 13 is a temperature detection element that detects the temperature of the gas inside the inner cylinder 3, and 14 is a temperature detection element that detects the temperature of water 15 injected into the bottom of the outer cylinder 2.

By the way, at the start of operation of the environmental tester configured as described above, each heater 4, 5, 10 is continuously energized, and the outer cylinder 2, which is a container for storing the test object, is heated.
After the internal temperature and humidity reach predetermined values, energization control (connection/disconnection or intensity adjustment) to each heater 4, 5, 10 is performed.
The inside of the outer cylinder 2 was maintained at a predetermined temperature and humidity. Therefore, the temperature of the gas inside the outer cylinder 2 and the temperature of the water 15 injected into the lower part of the outer cylinder 2 rise independently, and the temperature of the test object 11 housed in the outer cylinder 2 increases independently.
If the heat capacity of the test object 11 is large, the surface temperature of the test object 11 may become lower than the temperature of the water 15 heated by the heater 5. In this way, when the surface temperature of the test object 11 becomes lower than the temperature of the water 15, the water 1
5 evaporates and the water vapor contained in the gas inside the outer cylinder 2 condenses on the surface of the test object 11. If condensed water adheres to the surface of the test object and this surface becomes wet, the reliability of the accelerated test will be impaired, which is not preferable.

In addition, conventionally, each heater 4,
5 and 10 was stopped, the water 15 that had been injected into the outer cylinder 2 was drained, and the pressure inside the outer cylinder 2, which had risen due to water vapor, was lowered to atmospheric pressure. If the pressure inside the outer cylinder 2 containing the test object 11 is suddenly reduced, depending on the type of test object 11, unreasonable stress is likely to be applied to the test object 11.
Again, this is not preferable because it impairs the reliability of the test.

(Object of the present invention) The present invention provides a control method for an environmental tester that eliminates the above-mentioned disadvantages and allows accelerated testing using the environmental tester to be performed in good conditions regardless of the type of test object. is intended to provide.

(Structure of the present invention) The present invention consists of an invention (specific invention) of a method for controlling an environmental resistance tester so that water vapor does not condense on the surface of a test object at the start of a test, and The invention is divided into two inventions (derivative inventions) for controlling an environmental resistance tester so as to prevent excessive stress from being applied to the test object after the test is completed. Let's talk about.

a Structure of the Specified Invention The specified invention is based on the fact that at the start of a test, the heater for heating the gas in the container housing the test object is kept energized in principle, and the temperature inside the container is maintained at a constant gradient (°C/min). The amount of electricity applied to the heater for heating the water injected into the bottom of the container can be adjusted freely, and the temperature of the water is compared with the surface temperature of the sample to be measured. The configuration is such that the power supply to the heater for water heating is adjusted so that the surface temperature is equal to or lower than the surface temperature. However, mounting a temperature detection element on the surface of the test object 11 on which the accelerated test is actually performed may affect the test results, so in the present invention, the temperature detection element is A changing temperature sensing sample is used. This temperature detection sample is made of the same material, the same size, and the same shape as the test object 11. A temperature detection element for detecting temperature is embedded, and the test object 11 is placed in the inner cylinder 3 together with the test objects 11, 11 before performing an accelerated test. A signal indicating the surface temperature of the temperature detection sample is sent to a separately provided controller via a conductive wire. In addition, as for the installation location of the temperature detection sample, select a location where the temperature will rise like the test object 11, but choose a location where the conditions are the worst and where the temperature rise is likely to be delayed. Take measures to prevent the surface temperature from rising too quickly.

In order to start the accelerated test, electricity is first applied to the heaters 4 and 10 for heating the gas in the outer cylinder 2, which is a container for storing the test object, at _t1 in FIG. The temperature of the gas inside the outer cylinder 2 begins to rise as shown by the solid line a in the figure, and the surface temperature of the temperature detection sample housed in the outer cylinder 2 (same as the surface temperature of the test object 11) also increases accordingly. The vehicle starts to rise as shown by the chain line b. Once the gas temperature inside the outer cylinder 2 reaches a predetermined temperature, the amount of electricity applied to the heaters 4 and 10 is controlled to maintain the gas temperature at a constant value, but the surface temperature of the temperature detection sample also increases a little later. Matches the gas temperature of the lever. The power supply to the heater 5 for heating the water 15 injected into the bottom of the outer cylinder 2 is as follows.
This is done after the surface temperature of the temperature detection sample starts to rise, and after that the water temperature T _W shown by the broken line c is
Surface temperature T _S of the temperature detection sample shown by chain line b
The water temperature T W is increased while controlling the energization to the heater 5 so that the water temperature T _W is equal to or lower than (T _W ≦T _S ). The amount of current applied to the heater 5 is adjusted by comparing the indicated value of the temperature detecting element incorporated in the temperature detecting sample, which indicates the surface temperature of the test object 11, with the indicated value of the temperature detecting element 14, which indicates the water temperature. When the water temperature becomes sufficiently lower than the surface temperature of the test object 11, the heater 5 is energized (or the amount of current is increased), and when the water temperature becomes the same as or close to the surface temperature of the test object 11, the heater 5 is energized. This can be easily done by stopping (or reducing the amount of current).

In this way, if the surface temperature of the test object is always the same as or higher than the water temperature, the water at the bottom of the outer cylinder evaporates, and the water vapor contained in the gas condenses on the surface of the test object. Never.

b. Structure of the derived invention In the derived invention, the power supply to the water heating heater at the start of the test is controlled in the same manner as in the case of the specified invention described above, but when the test is completed, the water in the container is left as it is and the water heating heater is controlled. The power to the heater is stopped, the power to the heater for heating the gas in the container is freely turned on and off, and the surface temperature of the temperature detection sample is compared with the water temperature, and the water temperature is lower than the surface temperature of the temperature detection sample. The water temperature and gas temperature are constantly being lowered.

That is, at the start of the test, the power supply to the heater 5 is controlled in the same way as in the case of the above-mentioned specific invention, and the temperature of each part is increased as shown in the left part of Fig. 2, but after the test is finished, the water heating The power supply to the heater 5 is stopped and the water temperature is lowered as shown by the chain line on the right side of FIG. The gas temperature inside the outer cylinder 2 tends to drop more easily than the water temperature, and if left as it is, the surface temperature of the test object 11 will drop below the water temperature, so the water temperature and the surface temperature of the temperature detection sample should always be compared. When the difference between the surface temperature of the temperature detection sample and the water temperature becomes below a certain level, the heaters 4 and 5 are energized to heat the gas, and the water vapor in the gas in the outer cylinder 2 is heated to the temperature of the test object 11. Avoid condensation on surfaces. As the water temperature decreases, the water vapor contained in the gas condenses on the surface of the water 15, so the pressure inside the outer cylinder 2 gradually decreases, and at this time, the water vapor does not condense on the surface of the test object 11. .

(Effects of the present invention) Since the control method of the environmental resistance tester of the present invention is configured as described above, the surface of the test object may become wet at the start of the accelerated test, or the surface of the test object may become wet at the end of the test. Test results are not adversely affected by the application of unreasonable stress, and highly reliable tests can be performed.

[Brief explanation of the drawing]

Figure 1 shows one of the environmental testers to which the present invention applies.
A longitudinal side view showing an example, and FIG. 2 is a diagram showing changes in the gas temperature, water temperature, and temperature of the surface of the test object in the test device when the environmental test device is controlled by the method of the present invention. . 1... Lid, 2... Outer cylinder, 3... Inner cylinder, 4, 5...
...Heater, 6...Intake port, 7...Fan, 8a...
... Internal magnetic coupling piece, 8b... External magnetic coupling piece, 9... Motor, 10... Heater,
11... Test object, 12... Stand, 13, 14... Temperature detection element, 15... Water.

Claims (1)

[Scope of Claims] 1. A method for controlling an environmental resistance tester that conducts an accelerated test of the test object by making the inside of a container containing the test object hot and humid with steam, the method comprising: A temperature detection sample, which is an article with a heat capacity equipped with a temperature detection element that detects the surface temperature of this article, is placed in a container, and at the start of the test, the temperature is detected after power is applied to the heater to heat the gas in the container. After the surface temperature of the sample becomes equal to or higher than the temperature of the water injected into the bottom of the container, power is applied to the heater for heating the water. A method for controlling an environmental resistance tester, comprising increasing the water temperature and gas temperature while maintaining the water temperature below the surface temperature of the temperature detection sample by adjusting the amount. 2. A method for controlling an environmental tester that conducts accelerated testing of the test object by making the inside of the container containing the test object hot and humid with steam, which A temperature detection sample equipped with a temperature detection element that detects the surface temperature of the article is placed in a container, and at the start of the test, electricity is applied to the heater to warm the gas in the container, and the surface temperature of the temperature detection sample is measured. After the temperature of the water injected into the bottom of the container is equal to or higher than the temperature of the water, start energizing the heater for heating the water, and after starting energizing the heater for heating the water, adjust the amount of energization to this heater. The water temperature and gas temperature are increased while keeping the water temperature below the surface temperature of the temperature detection sample, and after the test is completed, electricity is turned on to the heater to heat the water at the bottom of the container without draining it. The water temperature and the gas temperature are lowered while the water temperature is kept below the surface temperature of the temperature detection sample by adjusting the current supply to the heater for heating the gas in the container. How to control an environmental tester.