JP4587971B2 - Environmental test equipment - Google Patents

Description

  The present invention relates to an environmental test apparatus. The environmental test apparatus of the present invention is suitable as an apparatus for testing the influence of humidity on a device under test. The environmental test apparatus of the present invention is suitable as an environmental test apparatus that maintains a high humidity environment for a long time.

An environmental test apparatus is known as an apparatus for evaluating the performance and durability of various devices and materials. As described in Patent Documents 1 and 2, the environmental test apparatus artificially creates a high-temperature environment, a low-temperature environment, or a high-humidity environment, and places a test object in this environment.
In a typical environmental test, a test object is continuously exposed to a harsh environment such as high temperature and high humidity for a long time to examine changes and deterioration of the test object.

In general, an environmental test apparatus includes a blower in addition to a heater and a refrigerator. In order to keep the environmental state in the environmental test chamber constant, the environmental test apparatus of the prior art performs the test by circulating air controlled at a constant temperature and humidity at a high speed (wind speed of about 1 m / second or more). . That is, the environmental testing apparatus of the prior art always circulates high-speed air.
Japanese Patent Laid-Open No. 3-48780 JP 2001-147251 A

Incidentally, electronic devices, electronic parts, polymer materials, and the like are generally strongly influenced by humidity. Therefore, manufacturers and researchers of electronic devices and the like need to test the influence of humidity. There is also a demand to know the change in moisture absorption of the DUT during the test.
However, the conventional environmental test apparatus has been dissatisfied with being unable to monitor the amount of moisture absorption that changes from time to time during the test.

Moreover, since the environmental test apparatus is continuously operated for an extremely long time and the blower is always rotated at a high speed, there is a complaint that the power consumption of the blower is large.
In recent years, when testing an electronic substrate, an environmental test may be performed in an energized state, but the electrical characteristics of the electronic substrate may become unstable due to the influence of air flow. Further, during the test, there was a problem that the water droplets adhering to the test chamber were blown off by blowing and adhered to the test object. In addition, a minute test object such as a powder or a light test object such as a film may be blown or changed in posture by blowing.
In particular, environmental tests may be performed continuously over a long period of time, so that it can be said that sudden failure of the DUT tends to occur due to the above-described disturbance of electrical characteristics, adhesion of water droplets, and scattering. In addition, once the above-described problems occur, the data up to that point is wasted, and the test may have to be performed again from the beginning.

  On the other hand, if the speed of the wind flowing through the environmental test apparatus is reduced, most of the above-mentioned problems are eliminated. However, the amount of moisture absorption has a correlation with the wind speed flowing in the apparatus, and if the wind speed is lowered, the desired moisture absorption amount cannot be reached, resulting in a fatal defect that the reliability of the experimental data is lowered. .

In the field of electronic equipment and electronic components, there is a demand for conducting an environmental test in a state where the amount of moisture absorption and the moisture absorption rate (the amount of moisture absorption per unit time) are controlled. For example, there is a demand to perform a test in an environment where water vapor is continuously absorbed at a constant rate for a certain period of time, or to perform a test in a state where the moisture absorption amount of the DUT is maintained within a predetermined range.
However, no environmental testing apparatus that satisfies this requirement is known.

  Therefore, the present invention solves the above-described problems of the prior art, and a first object is to provide an environmental test apparatus capable of knowing a change in moisture absorption amount of a test object during a test. .

  Another object is to provide an environmental test apparatus that can eliminate various problems caused by air blowing.

  Still another object is to provide an environmental test apparatus capable of creating an environment in which the water absorption rate or the like of a test object is a predetermined condition.

In order to solve the above-described problems, the present inventors have repeatedly studied the relationship between the wind speed of the wind and the amount of moisture absorption.
As a result, as described above, there is a strong correlation between the air blowing amount and the moisture absorption amount, and when the air blowing amount increases, the moisture absorption amount per unit time increases.
However, after the DUT sufficiently absorbed moisture and became saturated, the amount of moisture absorption did not increase even if the amount of air blown was increased.
Further, after reaching the saturation state, it was found that the moisture absorption amount of the DUT did not change even if the air flow rate was decreased. That is, once the moisture absorption amount is saturated, the movement of water vapor between the DUT and the outside air correlates with the temperature and humidity of the environment, and it has been found that there is no relationship with the air flow rate. . More specifically, once the DUT absorbs moisture to a saturated state, the moisture content of the DUT does not change even if the amount of blown air is reduced.

The invention completed on the basis of the above knowledge (Claim 1 ) is provided with an environment adjusting means for adjusting the environment in which the object to be tested is placed , and is an environment test apparatus for continuously testing the device under test in a test environment. A moisture absorption condition detecting means for detecting the moisture absorption condition of the object, wherein the environment adjusting means has at least a blowing means and a blowing environment control means, and changes the blowing environment according to the moisture absorption condition of the test object. It is an environmental test device.

In environmental testing apparatus of the present invention, since changing the blowing environment in accordance with the moisture status of the DUT under test environment, it satisfies the test condition, and it is possible to create an environment in which adverse effects of blowing does not take place.

According to a second aspect of the present invention, there is provided an environmental adjusting means for adjusting the environment in which the DUT is placed , and in the environmental test apparatus for performing the test continuously, the moisture absorption state of the DUT under the test environment is detected. An environmental test comprising a moisture absorption condition detecting means, wherein the environment adjusting means has at least a blowing means and a blowing environment control means, and reduces the blowing amount when the moisture absorption amount of the DUT satisfies a predetermined condition. Device.

  In the environmental test apparatus of the present invention, the amount of blown air is reduced when the moisture absorption amount of the DUT satisfies a predetermined condition. Therefore, it is possible to satisfy the test conditions and reduce the amount of blown air to prevent the harmful effects of the blown air.

The invention according to claim 3 is the environmental test apparatus according to claim 1 or 2 , characterized in that the amount of blown air is reduced on condition that the moisture absorption amount of the test object is saturated.

  As described above, when the moisture absorption amount of the DUT becomes saturated, the moisture content of the DUT does not change even if the blast volume is reduced thereafter, so that the blast volume can be reduced. The power consumption of the blower can be reduced by reducing the amount of blown air. In addition, harmful effects caused by blowing are also prevented.

The invention described in claim 4 is characterized in that the rate of change in moisture absorption of the DUT is detected, and the amount of blown air is reduced on condition that the rate of change in moisture absorption is below a certain level. It is an environmental test apparatus in any one of 1-3 .

  When the DUT is placed in a high humidity environment, it absorbs moisture from the surrounding environment. The amount of moisture absorption per unit time (change rate of the amount of moisture absorption) decreases as the amount of moisture absorption approaches the saturation state. Therefore, the degree of saturation of the DUT can be determined by detecting the change rate of the moisture absorption amount of the DUT. Therefore, the present invention detects the change rate of the moisture absorption amount of the test object, and reduces the air flow rate on the condition that the change rate of the moisture absorption amount is not more than a certain value.

The invention of environmental test device capable environmental testing of controlled water absorption rate and the like of the DUT is provided with an environment adjusting means for adjusting the environment DUT is placed in a environmental test apparatus for performing a continuous test, the with moisture status detection means for detecting the moisture status of the DUT under environment, the environment adjusting means has at least the blowing means and the blower environmental control means, moisture absorption condition of the test object satisfies a predetermined condition In this way, the air blowing environment is changed (Claim 5 ).

As described above, there is a strong correlation between the blown air and the moisture absorption amount, and the moisture absorption amount per unit time increases as the blown air amount increases.
Therefore, in order to change the amount of moisture absorption per unit time, the air blowing environment may be changed. The above-described invention according to claim 5 is based on the above-described idea, and changes the air blowing environment so that the moisture absorption state of the test object satisfies a predetermined condition. According to the present invention, it is possible to create an environment in which the moisture absorption state of the DUT satisfies a predetermined condition.

The invention according to claim 6, environmental testing apparatus according to claim 5, characterized in that the change in the change of the moisture absorption or moisture absorption DUT changes the blowing environment so as to satisfy a predetermined condition It is.

  In the environmental test apparatus of the present invention, it is possible to create an environment in which a change in the moisture absorption rate or a change in the moisture absorption amount of the test object satisfies a predetermined condition.

The invention described in claim 7 is provided with humidity adjusting means for adjusting the humidity of the environment in which the DUT is placed, and the environment in which the DUT is placed so that the moisture absorption state of the DUT satisfies a predetermined condition. an environmental test apparatus according to claim 5 or 6, wherein adjusting the humidity.

  The environmental test apparatus of the present invention creates an environment in which a change in the moisture absorption rate or a change in the moisture absorption amount of a test object satisfies a predetermined condition by changing not only the air blowing environment but also the humidity.

The moisture status detecting means, it is possible to employ those which detect the moisture status based on the weight of the DUT (claim 8).
Of course, the rate of change in the amount of moisture absorbed by the DUT can be known from the rate of change in weight.

Further, the moisture absorption status detecting means may detect the moisture absorption status based on the electrical characteristics of the test object (claim 9 ).
Similarly, the change rate of the moisture absorption amount of the DUT can be known from the change rate of the electrical characteristics.

The environmental test apparatus of the present invention is particularly suitable for performing a test for maintaining a constant environment for a long time (claim 10 ).

Further, the related invention is provided with an environmental adjusting means for adjusting an environment in which the DUT is placed , and in an environmental test apparatus for performing a continuous test, a moisture absorption status detecting means for detecting the moisture absorption status of the DUT under the test environment. It is an environmental test apparatus characterized by including.

Since this environmental test apparatus includes a moisture absorption state detecting means for detecting the moisture absorption state of the DUT under the test environment , it is possible to know the amount of moisture absorption that changes every moment during the test.

The environmental test apparatus of the present invention has an effect of eliminating various problems caused by air blowing while ensuring the reliability of experimental data.
The environmental test apparatus of the present invention has an effect that it is possible to know the moisture absorption status of the DUT under the test environment .
Moreover, the environmental test apparatus of this invention has the effect which can give the environment which controlled the change of the moisture absorption rate of the to-be-tested object.

Embodiments of the present invention will be further described below.
FIG. 1 is a configuration diagram of an environmental test apparatus according to an embodiment of the present invention.
The environmental test apparatus 1 of this embodiment includes a constant temperature and humidity chamber (environmental test chamber) 3 surrounded by a heat insulating material 2, and the environment in the constant temperature and humidity tank 3 is controlled by the control device 4.
As described above, the constant temperature and humidity chamber 3 has a function of arbitrarily adjusting the internal environment such as the internal temperature and humidity. First, a schematic configuration of the thermostatic chamber 3 and means for adjusting the environment in the thermostatic chamber 3 will be described.

  The interior of the constant temperature and humidity chamber 3 is divided up and down by a partition plate 9 and divided into a DUT placement chamber 5 and an air conditioning passage 6 as shown in FIG. The air conditioning passage 6 is located below the DUT placement chamber 5 and has openings 7 and 8 communicating with the DUT placement chamber 5 on both sides. One opening 7 functions as a suction side opening, and the other opening 8 functions as an opening for ventilation.

An indoor temperature detection sensor 11 and a humidity detection sensor 12 are provided in the DUT placement chamber 5 and in the vicinity of the ventilation opening 8.
The indoor temperature detection sensor 11 is specifically a thermocouple.
Detection signals from the indoor temperature detection sensor 11 and the humidity detection sensor 12 are input to the control device 4 as shown in FIG.

A humidifier 15, an air cooling heat exchanger 16, a dehumidifying heat exchanger 17, a heater 18 and a blower 20 are arranged in the lower air conditioning passage 6.
As the humidifier 15, the air cooling heat exchanger 16, the dehumidifying heat exchanger 17 and the heater 18, all known ones can be adopted.
In the present embodiment, a blower 20 that can arbitrarily change the rotation speed is employed. That is, the motor 21 that rotates the blower 20 is a DC motor or an inverter-controlled AC motor, and the number of rotations is variable.
The humidifier 15, the air cooling heat exchanger 16, the dehumidifying heat exchanger 17, the heater 18, and the blower 20 are each connected to a driving device such as a relay, and a signal from the control device 4 as shown in FIG. 1. To work.

  In the environmental test apparatus 1 of this embodiment, the air in the constant temperature and humidity chamber 3 is circulated by the blower 20 and passes through the air conditioning passage 6 to create a desired environment. That is, the air in the constant temperature and humidity chamber 3 is sucked from the suction side opening 7 of the air conditioning passage 6 by the blower 20, passes through the air conditioning passage 6, and exits to the ventilation opening 8. At this time, the air passes through the air cooling heat exchanger 16 and the dehumidifying heat exchanger 17 and further touches the heater 18. Moreover, water vapor | steam is supplied from the humidifier 15 as needed.

  A setting input means 22 such as a numeric keypad or a touch panel is connected to the control device 4 of the environmental test apparatus 1 so that a desired environment in the constant temperature and humidity chamber 3 can be set and input. Moreover, the display apparatus 23 is connected to the control apparatus 4, and the setting content and the environment in the constant temperature and humidity chamber 3 are displayed numerically.

In the environmental test apparatus 1, the temperature and humidity in the DUT placement chamber 5 are monitored by the indoor temperature detection sensor 11 and the humidity detection sensor 12. When the temperature in the DUT placement chamber 5 is lower than the temperature of the set environment, the heater 18 is energized to raise the temperature of the air, and the temperature in the DUT placement chamber 5 is higher than the temperature of the set environment. When the temperature is high, the refrigerant is passed through the air cooling heat exchanger 16 to lower the temperature of the air cooling heat exchanger 16 and take heat away from the circulating air.
Further, when the humidity in the DUT placement chamber 5 is lower than the humidity of the set environment, steam is injected from the humidifier 15 and mixed into the passing air.
Conversely, when the humidity in the DUT placement chamber 5 is higher than the humidity in the set environment, the dehumidifying heat exchanger 17 condenses the water vapor.

Next, a configuration and function peculiar to the environmental test apparatus 1 of the present embodiment will be described.
In addition, although the environmental test apparatus 1 of this embodiment can also be made into a test object about a polymeric material etc. besides the board | substrate 30 mentioned later, suppose that the board | substrate 30 is tested as an example in the following description.
The environmental test apparatus 1 of the present embodiment can test the substrate 30 and the like on which electronic components such as ICs are mounted, and has a specific configuration for that purpose. That is, the environmental test apparatus 1 according to the present embodiment includes power supply terminals 32 and 33 for supplying power to a device under test such as the substrate 30.

Further, a moisture absorption state detecting means 35 for monitoring the moisture absorption state of the substrate 30 is provided. The moisture absorption state detection means 35 is for indirectly monitoring the moisture absorption state by detecting the leakage current of the substrate 30. Specifically, the moisture absorption state detection unit 35 includes two electrodes 36 and 37 and a leakage current detection device 38. ing. Circuit of moisture status detection unit 35 is as in Figure 2, a constant current source 40 is composed of a voltmeter 41 and a resistor 42.
As shown in FIG. 2, a constant current is supplied to the substrate 30 through the electrodes 36 and 37. A voltmeter 41 is connected in parallel with the substrate 30. Therefore, the voltage between the terminals of the voltmeter 41 changes depending on the leakage current of the substrate 30. This voltage variation is converted into a current change by the resistor 42 and input to the control device 4. In the control device 4, the amount of moisture absorption is calculated based on the change in the input current value.

  That is, the control device 4 employed in the present embodiment includes a calculation unit that calculates the moisture absorption amount, the moisture absorption rate, and the like of the substrate 30 from the signal transmitted from the moisture absorption state detection unit 35. In reality, the control device 4 has a built-in CPU, and the calculation unit is configured by software.

From the control device 4, a signal for controlling the measurement cycle is transmitted to the leak current detection device 38, and current is transmitted from the constant current source 40 to the substrate 30 according to this signal. As described above, the leakage current is measured, and the amount of moisture absorption is calculated based on this value.
The change in the moisture absorption amount is stored as recording data in a memory (not shown) of the control means. Further, it is displayed on the display device 23 as necessary.

Further, the control device 4 includes a determination unit that determines whether or not the rate of change R (the amount of change per unit time) of the current output from the moisture absorption state detection unit 35 is equal to or less than a certain threshold value. The determination unit is also configured by software.
The leakage current of the substrate 30 has a correlation with the total moisture absorption amount of the substrate 30, and the leakage current increases when the moisture absorption amount is large. Therefore, when the dry substrate 30 is placed in a high humidity environment at the initial stage of the test, the amount of moisture absorption per unit time is large, and the rate of change in the total amount of moisture absorption of the substrate 30 is high. Therefore, when the dry substrate 30 is placed in a high humidity environment at the beginning of the test, the rate of change R (the amount of change per unit time) of the current output from the moisture absorption state detecting means 35 is high.

On the other hand, when moisture absorption with respect to the substrate 30 progresses and approaches a saturated state, the moisture absorption amount per unit time decreases, and the rate of change in the total moisture absorption amount of the substrate 30 decreases.
Therefore, if the rate of change of the total moisture absorption is below a certain level, it is estimated that the substrate 30 is in a saturated state or a state close to the saturated state.
Further, as described above, since there is a correlation between the total moisture absorption amount of the substrate 30 and the leakage current of the substrate 30, the change rate R (change amount per unit time) of the current output from the moisture absorption state detecting means 35 is obtained. If it becomes below a certain level, it is estimated that the board | substrate 30 is approaching a saturated state.

  And the control apparatus 4 will issue the signal which reduces the ventilation volume of the air blower 20, if the change rate of the leakage current of the board | substrate 30 which the moisture absorption condition detection means 35 detects becomes below a fixed threshold value. That is, if the moisture absorption amount of the substrate 30 is saturated, the air blowing amount is decreased.

  Next, the function of the environmental test apparatus 1 according to the present embodiment will be described following the actual test procedure with reference to FIG. FIG. 3 is a flowchart showing the operation of the environmental test apparatus of this embodiment.

  The environmental test apparatus 1 of this embodiment inspects the substrate 30 as described above, and sets test conditions as a test preparation stage. That is, the temperature and humidity in the constant temperature and humidity chamber 3 on which the substrate 30 is installed and their allowable ranges are set. Moreover, the test performed with the environmental test apparatus 1 of this embodiment is continuously performed over a long time, and the test time is also set.

  Subsequently, a substrate 30 as a test object is installed in the constant temperature and humidity chamber 3. Specifically, the substrate 30 is placed in the DUT placement chamber 5. Then, the power supply terminals 32 and 33 provided in the DUT placement chamber 5 are connected to a power supply terminal (not shown) of the substrate 30. The electrodes 36 and 37 are also connected to the substrate 30.

When ready, begin testing. Hereinafter, the environmental test apparatus 1 functions as shown in the flowchart of FIG.
That is, when the environmental test apparatus 1 is activated, it is determined in step 1 whether or not necessary setting input has been completed. If the necessary setting input has been made, the process proceeds to step 2 to determine whether or not a test start switch (not shown) is turned on. If the test start switch is ON, the process proceeds to step 3 to start a test and a predetermined measurement.
Specifically, the humidifier 15, the air cooling heat exchanger 16, the dehumidifying heat exchanger 17, and the heater 18 are activated and controlled so that the environment in the constant temperature and humidity chamber 3 becomes the target environment. The amount of blown air is controlled so that the wind speed in the constant temperature and humidity chamber 3 is about 0.1 m / second to 2 m / second.

  Then, in steps 4 and 5, the moisture absorption rate and various signals of the substrate 30 to be tested are measured and stored in a memory (not shown) of the control device 4 while being detected by the moisture absorption state detecting means 35 described above. The change rate of the leakage current is monitored, and it is waited for the change rate to be equal to or less than the threshold value.

The rate of change in leakage current is large immediately after the start of the test, but decreases with the passage of time. That is, immediately after the start of the test, the rate of change in leakage current is large because the amount of moisture absorption per unit time is large. However, the rate of change in leak current also decreases because the amount of moisture absorption per unit time gradually decreases as it approaches a saturated state.
If the rate of change is less than or equal to the threshold value and the answer to step 5 is yes, the process proceeds to step 6 to reduce the air flow rate. The amount of blown air is reduced to 50% or less, more desirably about 30%. For example, the air velocity in the constant temperature and humidity chamber 3 is lowered to 0.5 m / second or less, more desirably about 0.3 m / second.
That is, when the moisture absorption amount of the substrate 30 is saturated, the air flow rate in the constant temperature and humidity chamber 3 is reduced and the wind speed is reduced.
Of course, the test is continued even after the air flow is reduced.

  If it is determined in step 7 that the set test time has ended, the test is stopped.

  FIG. 4 is a graph showing changes with time in wind speed, temperature and humidity in a constant temperature and humidity chamber when experimenting with silica gel in the environmental test apparatus of the present embodiment, and the moisture absorption rate of silica gel as a test object. It is a graph which shows the change accompanying the time passage of (the amount of water supply with respect to the mass of silica gel).

As is apparent from the graph, the wind speed in the constant temperature and humidity chamber 3 is fast (0.9 m / s) immediately after the start of the test. Moreover, the temperature and humidity in the constant temperature and humidity chamber 3 are stabilized very early. The temperature in the thermostatic chamber 3 is 85-C, and the humidity is 85%.
Silica gel, moisture absorption rate slide into increasing with the passage of time. While after start of the test is the rate of change of the moisture absorption rate (slope of the graph) is constant, the rate of change of moisture absorption rate (slope of the graph) decreases when passed about three hours from the start of the test. Finally, it becomes saturated and there is no fluctuation in the water absorption rate.

At this time, the wind speed in the constant temperature and humidity chamber 3 decreases rapidly and becomes 0.3 m / s. However, the temperature and humidity in the constant temperature and humidity chamber 3 maintain a stable state, and no change is observed.
Thereafter, the test was continued with the wind speed in the constant temperature and humidity chamber 3 lowered, but the moisture absorption amount of the silica gel did not change, and the reliability of the environmental test was high.
Moreover, since the wind speed in the constant temperature and humidity chamber 3 is low during the test, the power consumption of the blower 20 is low. In addition, there is no problem of silica gel flying by blowing.

In the embodiment described above, the air flow rate is adjusted by changing the number of revolutions of the motor 21 of the blower 20, but it is also possible to increase or decrease the air flow rate by providing a damper or the like and adjusting the opening of the damper. is there.
Further, a wind direction plate or the like for controlling the direction of the wind may be provided, and the actual air volume in contact with the substrate may be increased or decreased by changing the wind direction.
Further, as in the embodiment shown in FIG. 5, a wind speed sensor 45 is provided in the DUT placement chamber 5, and the rotational speed of the motor 21 and the opening of the damper are controlled while monitoring the wind speed detected by the wind speed sensor 45. May be. Since the environmental test apparatus 50 shown in FIG. 5 is the same as the environmental test apparatus 1 in FIG. 1 except that the wind speed sensor 45 is provided, detailed description will be given by attaching the same numbers to the same members. Replace.

  The apparatus shown in FIG. 5 detects the overall wind speed of the air flowing through the DUT placement chamber 5 by the wind speed sensor 45, but by devising the position, direction and number of the wind speed sensors 45, It is good also as a structure which detects the wind speed of the wind which contacts the board | substrate 30 directly, the wind speed of the surface direction of the board | substrate 30, or an air volume.

In the above-described embodiment, the air flow rate is changed stepwise, but the air flow rate may be increased or decreased according to the moisture absorption amount of the DUT.
For example, the air volume and the wind speed may be proportionally controlled according to the difference between the saturated moisture absorption amount and the current moisture absorption amount.
In the above-described embodiment, the moisture absorption state is indirectly monitored by detecting the leakage current of the substrate 30. However, as another measure, the moisture absorption state can also be detected by a change in resistance of each part of the substrate 30.
That is, as shown in FIG. 6, the resistance value between each part (for example, ai) of the board | substrate 30 is monitored. Here, since the resistance value of the DUT such as the substrate 30 generally changes slightly depending on the moisture absorption amount, it is possible to indirectly detect the moisture absorption amount of the substrate 30 by monitoring the change in the resistance value of each part. it can.
In particular, since the environmental test apparatus according to the present embodiment can perform a test while energizing the substrate 30, it is easy to monitor changes in current and voltage flowing through each part. By monitoring changes in current and voltage, changes in electrical characteristics can be detected, and the amount of moisture absorbed can also be known indirectly.
Similarly, a method of indirectly knowing the amount of moisture absorption by detecting a change in impedance is also conceivable.

  Further, as shown in FIG. 7, in place of the moisture absorption state detection means for detecting electrical characteristics, a weight measuring device 60 such as a load cell is installed in the constant temperature and humidity chamber 3 as the moisture absorption state detection means 35, and the weight measurement device The moisture absorption amount can also be known by constantly monitoring the weight of the substrate 30 at 60. That is, if the amount of moisture absorption increases, the weight of the substrate 30 increases, and if the substrate 30 dries, the weight decreases. Therefore, the moisture absorption amount can be known by monitoring the weight of the substrate 30.

Moreover, the environmental test apparatus of the present invention is suitable as an environmental test apparatus for maintaining a high humidity environment for a long time, but it can also be used as an environmental test apparatus for periodically changing humidity and the like.
For example, as in the time chart shown in the upper part of FIG. 8, the rising side transition period in which the low humidity shifts to the high humidity, the high humidity stable period in which the high humidity state is stabilized, and the falling side transition in which the high humidity state shifts to the low humidity. The present invention can also be applied to an environmental test apparatus for repeatedly testing the period and the low humidity stable period in which the low humidity state is stable.

  Explaining along the time chart, the period between a and b is an ascending-side transition period in which low humidity shifts to high humidity, and the period between b and c is a high humidity stable period in which the high humidity state is stable. Further, the period between cd is a descending side transition period in which the transition is from high humidity to low humidity, and the period between der following this is a low humidity stable period in which the low humidity state is stable. Then, the rising side transition period is reached again at ef, and thereafter, the high humidity stable period, the falling side transition period, and so on are repeated sequentially.

The moisture absorption amount of the DUT at this time is low at the start of the test as shown in the lower part of the figure, increases in the rising transition period between a and b, and then saturates in the high humidity stable period between b and c. State.
Further, the moisture absorption amount of the DUT decreases during the downward transition period between cd, and the moisture absorption amount becomes minimum during the low humidity stable period between der.

And in the environmental test apparatus 1 of this embodiment, the rotation speed of the air blower 20 can be changed in two stages, and as shown in the middle time chart of FIG. When the amount of moisture absorption is high, the rotational speed of the blower 20 is decreased.
Therefore, the blower 20 is rotated at a low speed for a considerable time within the test time, and the power consumption is small.

  In addition, each of the above-described embodiments is intended to shorten the time required for the DUT to absorb moisture and the time required to release water vapor, and the amount of air blown until the moisture absorption rate and the amount of moisture absorption become constant values. Conversely, the air flow rate is increased or decreased so that the moisture absorption rate or moisture absorption amount is within a certain range, or the rate of change of moisture absorption rate or moisture absorption amount is within the specified range. The air volume or the like may be increased or decreased. This will be described below.

The flowchart shown in FIG. 9 is a flowchart showing the operation of the environmental test apparatus according to the second embodiment of the present invention. FIG. 10 is a time chart showing the operation of the environmental test apparatus according to the second embodiment of the present invention and the change in the moisture absorption amount of the test object.
9, flows chart and a time chart shown in FIG. 10, it shows the operation when either changes in the moisture amount per unit time of the DUT (change of moisture absorption) to make such an environment is constant It is.

In the environmental test apparatus of the present embodiment, the rate of change in the moisture absorption amount of the DUT is monitored during the test period, and the amount of air blown is increased or decreased in proportion to the difference from the target change amount.
That is, when the environmental test apparatus 1 is activated, it is determined in step 1 whether or not necessary setting input has been completed. Here, since the environment test apparatus of the present embodiment creates an environment in which the change in moisture absorption per unit time (change in moisture absorption rate) is constant, a desired amount of change in moisture absorption rate is set. In the present embodiment, as shown in the time chart at the bottom of FIG. 10, a constant amount of moisture absorption per unit time and a constant amount of moisture release per unit time are repeatedly performed.

If the necessary setting input has been made, the process proceeds to step 2 to determine whether or not a test start switch (not shown) is turned on. If the test start switch is ON, the process proceeds to step 3 to start a test and a predetermined measurement.
Specifically, the humidifier 15, the air cooling heat exchanger 16, the dehumidifying heat exchanger 17, and the heater 18 are activated, and the moisture absorption amount of the test object placed in the constant temperature and humidity chamber 3 is predetermined. The target environment is controlled so as to change along the pattern.

  Then, the rate of change in the moisture absorption amount of the DUT is monitored from step 4 to step 7, and the air flow rate is increased or decreased so that the rate of change in the moisture absorption amount falls within an appropriate range.

Specifically, it is determined in step 4 whether the rate of change in moisture absorption is excessive. If the rate of change is larger than the set range, the process proceeds to step 5 to decrease the air flow rate, and then proceeds to step 8. If step 4 is NO, the process proceeds to step 6 to determine whether or not the rate of change is too small. If the rate of change is too small, the process proceeds to step 7 to increase the air flow rate, and then proceeds to step 8.
If step 6 is NO, the rate of change is within the appropriate range, so the process proceeds to step 8 without changing the air flow rate.
In step 8, it is determined whether there is a test end signal. Specifically, it is determined whether or not a certain repetition has been completed.
If a signal indicating the end of the test is confirmed in step 8, the test is terminated.

  The time chart in the series of tests described above is as shown in FIG. 10, and the moisture absorption contained in the DUT is increased at a constant rate (change rate) between a and b as in the time chart shown in the lower part. Then, between b and c, the high humidity stable period is saturated, and the distance between c and d is decreased at a constant rate.

  Therefore, during the period in which the moisture absorption amount changes, that is, between ab and cd, the blown air amount changes according to the deviation of the change amount.

  In the above-described embodiment, the air flow rate is changed in order to control the rate of change of the moisture absorption amount, but at the same time, the humidity is controlled to be higher or lower than usual so that the control of the moisture absorption amount by changing the air flow rate is achieved. May be raised.

It is a block diagram of the environmental test apparatus of embodiment of this invention. It is a circuit diagram of the moisture absorption condition detection means employ | adopted with the environmental test apparatus of this embodiment. It is a flowchart which shows operation | movement of the environmental test apparatus of this embodiment. A graph showing changes with time in wind speed, temperature and humidity in a constant temperature and humidity chamber when an experiment was conducted with silica gel in the environmental test apparatus of the present embodiment, and the moisture absorption rate of silica gel as a test object (mass of silica gel It is a graph which shows the change with the passage of time of water supply amount). It is a block diagram of the environmental test apparatus of other embodiment of this invention. It is explanatory drawing which shows other embodiment which measures the moisture absorption amount of a board | substrate. It is explanatory drawing which shows other embodiment which measures the moisture absorption of a board | substrate. It is a time chart which shows the example of operation | movement of the environmental test apparatus of this embodiment, and the moisture absorption amount change of the to-be-tested object accompanying this operation | movement. It is a flowchart which shows operation | movement of the environmental test apparatus of 2nd embodiment of this invention. It is a time chart which shows the example of operation | movement of the environmental test apparatus of 2nd embodiment of this invention, and the moisture absorption amount change of the to-be-tested object accompanying this operation | movement.

DESCRIPTION OF SYMBOLS 1,50 Environmental test apparatus 3 Constant temperature / humidity tank 4 Control apparatus 11 Indoor temperature detection sensor 12 Humidity detection sensor 15 Humidifier 16 Air-cooling heat exchanger 17 Dehumidification heat exchanger 18 Heater 20 Blower 21 Motor 22 Setting input means 23 Display device 30 Substrate (test object)
35 Moisture absorption status detection means 45 Wind speed sensor

Claims (10)

An environmental testing apparatus that continuously adjusts an environment adjustment unit that adjusts an environment in which the DUT is placed , and further includes a moisture absorption state detection unit that detects a moisture absorption state of the DUT in the test environment. The means has at least air blowing means and air blowing environment control means, and changes the air blowing environment according to the moisture absorption state of the object to be tested. An environmental testing apparatus that continuously adjusts an environment adjustment unit that adjusts an environment in which the DUT is placed , and further includes a moisture absorption state detection unit that detects a moisture absorption state of the DUT in the test environment. The means has at least air blowing means and air blowing environment control means, and reduces the air blowing amount when the moisture absorption amount of the DUT satisfies a predetermined condition. Environmental testing apparatus according to claim 1 or 2, characterized in that reducing the air volume on the condition that the moisture absorption of the test object becomes a saturated state. The environment according to any one of claims 1 to 3 , wherein a change rate of the moisture absorption amount of the DUT is detected, and the air flow rate is reduced on condition that the change rate of the moisture absorption amount is a certain value or less. Test equipment. An environmental testing apparatus that continuously adjusts an environment adjustment unit that adjusts an environment in which the DUT is placed , and further includes a moisture absorption state detection unit that detects a moisture absorption state of the DUT in the test environment. The means has at least a blowing means and a blowing environment control means, and changes the blowing environment so that the moisture absorption state of the DUT satisfies a predetermined condition. 6. The environmental test apparatus according to claim 5 , wherein the air blowing environment is changed so that a change in moisture absorption rate or a change in moisture absorption amount of the test object satisfies a predetermined condition. Humidity adjustment means for adjusting the humidity of the environment where the DUT is placed is provided, and the humidity of the environment where the DUT is placed is adjusted so that the moisture absorption state of the DUT satisfies a predetermined condition. The environmental test apparatus according to claim 5 or 6 . Moisture status detecting means environmental test device according to any one of claims 1 to 7, characterized in that to detect the moisture status based on the weight of the DUT. The environmental test apparatus according to any one of claims 1 to 7 , wherein the moisture absorption state detecting means detects the moisture absorption state based on an electrical characteristic of the test object. Environmental testing apparatus according to any one of claims 1 to 9, characterized in that to maintain over a long time a certain environment.

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