JP2017015433A - Environmental test apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environmental test apparatus capable of automatically and accurately calculating optimum restart timing depending on test conditions.SOLUTION: A control unit 40 preliminarily starts up a refrigerator 24 while performing a high temperature test within an identical cycle to a present low temperature test, and calculates a time required for a cryostat 20 to reach a pre-cooling temperature and a temperature inclination based on temperature change. After temporarily stop the refrigerator 24, the control unit 40 restarts the cryostat 20 to reach a pre-cooled state until present low temperature test starts based on the temperature inclination.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an environmental test apparatus.

  As a background art of this technical field, the abstract of the following Patent Document 1 states that “the relationship between the cooling capacity of the low temperature bath and the target temperature arrival time and the heating capacity of the high temperature chamber and the target temperature arrival time is calculated, By controlling the operation of the electric heater in the high greenhouse and the operation of the refrigerator and electric heater in the cold room during the high temperature test, it has the effect of reducing the power consumption.

JP 2000-249643 A

Patent Document 1 describes an environmental test apparatus that performs an environmental test such as a thermal shock test of a test object by alternately repeating a low temperature test following a high temperature test (or preparatory operation) as one temperature cycle.
Of these, the low temperature test uses so-called precooling to start the refrigerator so that the low temperature chamber reaches the precooling temperature by the start time of this low temperature test using data collected before the end of the previous high temperature test. Is done.
The refrigeration capacity of the refrigerator required for pre-cooling the low temperature greenhouse depends on the test conditions such as the test temperature and the heat capacity of the cold room, and the optimal start-up timing of the refrigerator differs for each low temperature test. To do. For this reason, the cold start data of the previous temperature cycle is collected in advance, and the start-up timing of the refrigerator is calculated from the time until the low temperature bath reaches the precooling temperature.
However, during the period from the previous high temperature test to the pre-cooling of this low-temperature test (hereinafter also referred to as pre-cooling operation), external factors such as the amount of heat entering from the surroundings of the low-temperature tank and the frosting state of the refrigerator have changed. There is a risk that the prediction accuracy of the start-up timing of the refrigerator will be lowered.
Moreover, if the required time per one temperature cycle becomes long, it will become easy to be influenced by the change of an external factor, and also the prediction precision of the starting timing of a refrigerator will fall.
It is an object of the present invention to provide an environmental test apparatus that can automatically calculate an optimum restart timing according to test conditions with high accuracy.

In order to solve the above-described problems, the environmental test apparatus according to the present invention is configured so that the control unit starts the refrigerator preliminarily during the high temperature test in the same temperature cycle as the low temperature test until the low temperature bath reaches the precooling temperature. The temperature gradient is calculated from the elapsed time and the temperature change.
Then, after the refrigerator is temporarily stopped, it is restarted based on the temperature gradient so that the low temperature tank is in a precooled state before the start of the current low temperature test.

ADVANTAGE OF THE INVENTION According to this invention, the environmental test apparatus which can calculate automatically the optimal restart timing according to test conditions accurately can be provided.
Problems, configurations, and effects other than those described above will be clarified by the following embodiments.

1 is a schematic diagram of an environmental test apparatus according to a first embodiment of the present invention. 1 is a block diagram of an environmental test apparatus according to a first embodiment. The flowchart of the environmental test apparatus of 1st Embodiment. In the environmental test apparatus of 1st Embodiment, it is a time chart which shows a mode that the refrigerator once stopped is restarted during a high temperature test. 6 is a time chart showing a state in which the minimum temperature stabilization time is not ensured due to delay in restart in the environmental test apparatus of the first embodiment. 6 is a time chart showing a state in which the refrigerator is restarted at the time when the expected temperature stabilization time coincides with the temperature stabilization minimum time in the environmental test apparatus of the first embodiment. It is a schematic diagram explaining the structure of the environmental test apparatus of 2nd Embodiment. It is a time chart which shows a mode that the refrigerator once stopped in the environmental test apparatus of 2nd Embodiment is restarted during a high temperature test. It is a time chart which shows a mode that a refrigerator is restarted when the estimated temperature stabilization time corresponds with the minimum temperature stabilization time in the environmental test apparatus of 2nd Embodiment. It is a time chart which shows a mode that restart is late and the temperature stabilization minimum time is not ensured in the environmental test apparatus of 2nd Embodiment.

(First embodiment)
(overall structure)
The configuration of the environmental test apparatus 1 according to the first embodiment of the present invention will be described below with reference to the schematic diagram of the configuration shown in FIG. 1 and the block diagram shown in FIG.
In FIG. 1, an environmental test apparatus 1 is provided in a low temperature tank 20, a test tank 10 in which a DUT 70 is disposed, a low temperature tank 20 that communicates with the test tank 10 through vent holes 28 and 29. Refrigerator 24, low-temperature tank blower 27, high-temperature tank 30 communicating with the test tank 10 through ventilation ports 38, 39, high-temperature tank heater 36 provided in the high-temperature tank 30, and high-temperature tank blower 37.

Further, as shown in FIG. 2, the control unit 40 includes the refrigerator 24, the high-temperature tank side heater 36, the high-temperature tank fan unit 37, the low-temperature tank side fan 52, the high-temperature tank side fan 62, the test tank temperature sensor 12, and the low-temperature tank temperature. The sensor 22 and the high-temperature tank temperature sensor 32 are connected to each other. The detailed configuration of the control unit 40 will be described later.
The test tank 10 includes a test tank temperature sensor 12 that detects the temperature of the gas (atmosphere) in the test tank 10. The test tank temperature sensor 12 detects the temperature data of the gas in the test tank 10 and outputs it to the control unit 40.
The cryostat 20 includes a cryostat temperature sensor 22. The low temperature bath temperature sensor 22 detects the temperature of the gas in the low temperature bath 20 and outputs temperature data of the detected gas to the control unit 40.

  In the low temperature tank 20 of the first embodiment, a low temperature tank side heater 26 is provided together with the refrigerator 24. The low temperature tank heater 26 corrects the cooling power of the refrigerator 24. The refrigerator 24 is controlled by the control unit 40 and is started together with the low temperature tank heater 26 or independently, and is switched alternately so as to be in the operation state and the stop state. In the operating state, the gas in the low-temperature tank 20 is cooled to the pre-cooling temperature TL, which is a temperature necessary for pre-cooling (accumulation of pre-heating), and in the state where the low-temperature test CL is performed, the test tank temperature (A) Is maintained at the temperature of the low temperature test tank (B).

The low temperature tank blower 27 includes a low temperature tank blower 52, a low temperature side blowing opening / closing damper 50 and a low temperature side suction opening / closing damper 51 capable of opening and closing the ventilation ports 28 and 29. The low temperature side blowing opening / closing damper 50 and the low temperature side suction opening / closing damper 51 of this embodiment have actuators 54 and 55 that are operated by compressed air, an electric motor, or the like. The actuators 54 and 55 drive the low-temperature side blowing opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 in the direction of opening and closing in accordance with a control signal from the control unit 40 to open and close the ventilation ports 28 and 29.

The control unit 40 opens the low temperature side blowing opening / closing damper 50 and the low temperature side suction opening / closing damper 51 in a state where the low temperature tank side blower 52 is driven, and is cooled into the low temperature tank 20 through the vent holes 28 and 29. Supplied gas is cooled rapidly. By driving the low-temperature tank side blower 52, gas circulates around the DUT 70 arranged in the test tank 10 through the low-temperature tank 20, the vent 28, the test tank 10, and the vent 29. The temperature in the test tank 10 is brought close to the low temperature test temperature (C). Further, the control unit 40 closes the low temperature side blowing opening / closing damper 50 and the low temperature side suction opening / closing damper 51 in a state where the low temperature tank side blower 52 is driven, so that the inside of the low temperature tank 20 in the precooled state (cold heat accumulation state). Can be circulated in the cryostat 20.

The drive control of the low-temperature tank side blower 52 may be performed independently, or the low-temperature side blowing opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 may be opened and closed in synchronization. For example, the low temperature side blowing opening / closing damper 50 and the low temperature side suction opening / closing damper 51 may be opened in synchronization with the driving of the low temperature tank side blower 52. Further, the low temperature side blower opening / closing damper 50 and the low temperature side suction opening / closing damper 51 are closed in synchronism with the drive stop of the low temperature tank side blower 52 to block the gas flow between the test tank 10 and the low temperature tank 20. May be. In this case, the actuators 54 and 55 can be omitted. Furthermore, the mechanisms and operations of the low-temperature side blowing opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 are not limited to the configuration of the first embodiment, and may be further simplified or omitted.

The said control part 40 controls the high temperature tank side heater 36 provided in the high temperature tank 30, and switches an operation state and a stop state alternately. In the operating state, the gas in the high-temperature tank 30 can be heated to a preheated state.
The high-temperature tank blower 37 is operated by a high-temperature tank blower 62, a high-temperature side blowing opening / closing damper 60 and a high-temperature side suction opening / closing damper 61 that can open and close the ventilation ports 38 and 39, compressed air, an electric motor, and the like. Actuators 64 and 65 are provided. Further, the control unit 40 opens the high temperature side blowing opening / closing damper 60 and the high temperature side suction opening / closing damper 61 in a state where the high temperature tank side blower 62 is driven, and is arranged in the test tank 10 through the ventilation ports 38 and 39. Further, the gas in the high-temperature tank 30 that has been in a preheated state can be sent around the test object 70 and circulated. And the control part 40 closes the high temperature side blowing opening / closing damper 60 and the high temperature side suction opening / closing damper 61 in the state which is driving the high temperature tank side air blower 62, and makes the gas in the high temperature tank 30 in a preheating state the high temperature tank 30 can be circulated.

In the first embodiment, the low temperature side blow opening / closing damper 50, the low temperature side suction opening / closing damper 51, and the high temperature side blowing open / close damper 60 are provided using actuators 54, 55, 64, and 65 that are operated by compressed air, an electric motor, or the like. The high temperature side suction opening / closing damper 61 is opened / closed, but an actuator of any configuration and drive system may be used. For example, it may be opened and closed passively by wind force generated by driving the low and high temperature tank side fans 52 and 62. Alternatively, the low-temperature side blowing opening / closing damper 50, the low-temperature side suction opening / closing damper 51, the high-temperature side blowing opening / closing damper 60, and the high-temperature side suction opening / closing damper 61 may be opened / closed by using hydraulic pressure or the like to generate and transmit driving force. The shape, quantity, and material of the drive source and transmission member used for this purpose are not limited to the actuators 54, 55 and 64, 65 of the first embodiment.

(Configuration of control unit 40)
The said control part 40 switches the driving | running state and stop state of the said low temperature tank side air blower 52 and the high temperature tank side air blower 62 alternately. That is, based on the data detected by the test tank temperature sensor 12, the low temperature tank temperature sensor 22, and the high temperature tank temperature sensor 32, the control unit 40 mainly uses the refrigerator 24, the low temperature tank side heater 26, and the low temperature tank air blow. The low temperature test using the precooling state using the unit 27 and the high temperature test mainly using the preheating state using the high temperature tank heater 36 and the high temperature tank blower unit 37 can be performed alternately.

The control unit 40 of the first embodiment shown in FIG. 2 includes an input unit 41, a calculation unit 42, a timer unit 44, a storage unit 46, and an output unit 48, and is an application developed in a RAM. The functions realized by the program are shown as a block diagram.
The input unit 41 receives temperature data detected by the test bath temperature sensor 12, the low temperature bath temperature sensor 22, and the high temperature bath temperature sensor 32. In addition to this, the input unit 41 is connected to an external input device such as a keyboard or a communication device (not shown), for example, data relating to test conditions and test results, high and low temperature test repetition counts, or two zones (high temperature test / low temperature test). Test) or three-zone test (high temperature test / normal temperature test / low temperature test), and test condition data such as high and low temperature setting temperatures may be input.

The calculation unit 42 includes hardware as a general computer such as a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and an HDD (Hard Disk Drive). , OS (Operating System), application programs, various data, and the like are stored. The OS and application program are expanded in the RAM, executed by the CPU, and perform arithmetic processing according to data input to the input unit 41 together with the timer unit 44 and the storage unit 46.
The timer unit 44 measures the low temperature test time and the high temperature test time during which control is performed based on the test condition data, or the elapsed time after reaching a desired temperature.
The storage unit 46 stores test condition data or temporarily stores temperature data detected by the test bath temperature sensor 12, the low temperature bath temperature sensor 22, and the high temperature bath temperature sensor 32, and is read and written by the calculation unit 42. Memory or buffer (both not shown).

The output unit 48 outputs the calculation processing results to the refrigerator 24, the low temperature tank side heater 26, the low temperature tank side blower 52, the high temperature tank side heater 36, and the high temperature tank side blower 62 connected to the control unit 40. And the said refrigerator 24, the low temperature tank side heater 26, the low temperature tank side air blower 52, the high temperature tank side heater 36, and the high temperature tank side air blower 62 are each comprised so that a drive or a drive may be stopped according to a control signal. .
As described above, the control unit 40 outputs the control signal, thereby the gas in the low-temperature tank 20 that has been precooled by the low-temperature tank blower 27 and the high-temperature tank blower 37 or the high-temperature tank 30 that has been preheated. Is sent to the periphery of the DUT 70 arranged in the test tank 10 to perform a high temperature test and a low temperature test. The environmental test apparatus 1 can continuously perform a high temperature test and a low temperature test by alternately repeating a high temperature test and a low temperature test constituting one temperature cycle a plurality of times.

In the first embodiment, the low temperature side blowing opening / closing is controlled by controlling the driving of the actuators 54, 55, 64, 65 in accordance with the control signal output from the output unit 48 of the control unit 40 shown in FIG. The damper 50, the high temperature side blowing opening / closing damper 60, the low temperature side suction opening / closing damper 51, and the high temperature side suction opening / closing damper 61 are actively opened and closed.
For example, in the high temperature test, the low temperature side blow opening / closing damper 50 and the low temperature side suction opening / closing damper 51 are closed, and the high temperature side blowing open / close damper 60 and the high temperature side suction opening / closing damper 61 are opened.
In the low temperature test, the high temperature side blow opening / closing damper 60 and the high temperature side suction opening / closing damper 61 are closed, and the low temperature side blowing open / close damper 50 and the low temperature side suction opening / closing damper 51 are opened.

The control unit 40 alternately opens and closes the low temperature side blowing opening / closing damper 50, the low temperature side suction opening / closing damper 51, the high temperature side blowing opening / closing damper 60, and the high temperature side suction opening / closing damper 61.
As a result, the gas in the high temperature bath 30 in the preheated state is sent to the periphery of the DUT 70 in the test bath 10 where the low temperature test has been performed, and a high temperature test is performed in which a thermal shock is applied by rapid heating. Is called.
In addition, the gas in the low-temperature chamber 20 that has been in a precooled state is sent around the DUT 70 in the test chamber 10 in which the high-temperature test has been performed, and a low-temperature test in which a cooling shock is applied by rapid cooling is performed. .
By alternately repeating such a high-temperature test including a thermal shock or a low-temperature test including a cooling shock as one temperature cycle, the environmental test apparatus 1 can apply the thermal shock to the DUT 70.

Further, the control unit 40, based on the temperature data detected by the test tank temperature sensor 12, the low temperature tank temperature sensor 22, and the high temperature tank temperature sensor 32, the refrigerator 24, the low temperature tank side heater 26, and the low temperature tank side blower 52. As long as it controls the driving of the high temperature tank side heater 36 and the high temperature tank side blower 62, these controls can be realized by dedicated hardware (such as an electronic circuit), and are realized by software. You can also
The control unit 40 closes the low temperature side blowing opening / closing damper 50 and the low temperature side suction opening / closing damper 51 when the current high temperature test is started after the previous low temperature test is completed. Thereby, when performing the high temperature test in the same temperature cycle as this low temperature test, the ventilation openings 28 and 29 between the low temperature tank 20 and the test tank 10 will be closed and interrupted | blocked. Therefore, the gas in the low temperature tank 20 can be efficiently precooled by starting the refrigerator 24.
Further, in the precooling operation state, the control unit 40 controls the driving of the refrigerator 24 and the low temperature tank side heater 26 so that the low temperature tank 20 is maintained at a constant precooling temperature until the low temperature test is started. .

The control unit 40 of the first embodiment starts the operation of the refrigerator 24 during the high temperature test in the same temperature cycle as the current low temperature test (hereinafter referred to as “preliminary start”), and the low temperature tank 20 A temperature gradient α calculated from the elapsed time until the precooling temperature is reached and the temperature change is obtained. And the control part 40 stops the refrigerator 24 once, when the low-temperature tank temperature B of the low-temperature tank 20 reaches the precooling temperature TL. Furthermore, the control unit 40 restarts the refrigerator 24 that has been stopped based on the temperature gradient α calculated from the elapsed time until the low temperature tank 20 reaches the precooling temperature and the temperature change.
At this time, the refrigerator 24 reduces the actual driving time of the refrigerator 24 while securing a sufficient time for the low temperature bath 20 to be in a precooled state and kept stable before the start of the present low temperature test. Thus, the restart timing is set so as to improve the thermal efficiency.
As described above, the control unit 40 performs control of a test in which one temperature cycle for repeating the high temperature test and the low temperature test is continuously performed a plurality of times.

The flowchart shown in FIG. 3 is described focusing on the processing operation of the control unit 40 of the low temperature test performed this time among the processing performed by the control unit 40. A description of the high temperature test being performed at the same time is omitted. Further, a description will be given using a two-zone cycle test in which a high temperature test and a low temperature test are alternately performed without performing a normal temperature test.
Of these, steps S1 to S4 measure the time required for precooling of the refrigerator 24, which is required to calculate the temperature gradient α of the precooling control of the current low temperature test after the end of the previous low temperature test. Shows the processing to be performed.

In step S1, the control unit 40 changes the setting of the temperature of the low-temperature tank 20 to the precooling temperature (TL).
In step S <b> 2, when it is time a (see FIG. 4) at which the previous low-temperature test is completed and the high-temperature test is started, the control unit 40 starts timing by the timer unit 44. At this time, the data at time a measured by the timer unit 44 of the control unit 40 is stored in the storage unit 46.
In step S3, the calculation unit 42 of the control unit 40 compares the current low temperature bath temperature (B) with the precooling temperature (TL).
Here, the control signal from the output unit 48 of the control unit 40 turns on the high-temperature tank heater 36 to perform the high-temperature test CH, and drives the actuators 64 and 65 to blow out the high-temperature side of the ventilation ports 38 and 39. The open / close damper 60 and the high temperature side suction open / close damper 61 are opened. And the control part 40 drives the high temperature tank side air blower 62, and sends in the circumference | surroundings of the to-be-tested object 70 from the open vents 38 and 39 which were open | released the gas in the high temperature tank 30 which is in the preheating state by heating. .
At this time, the control unit 40 drives the actuators 54 and 55 to close the low-temperature side blowing opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 of the ventilation ports 28 and 29, so that the low-temperature tank 20 and the test tank 10 are connected. The gas flow between them is blocked.
During the pre-cooling operation of the present low temperature test CL, the control unit 40 of the first embodiment drives the low temperature tank side blower 52 to circulate the gas inside the low temperature tank 20 in the low temperature tank 20 to store cold.

Until the current low temperature bath temperature (B) reaches the precooling temperature (TL) in step S3 (NO in step S3), the calculation unit 42 repeats step S3, and the current low temperature bath temperature (B) is When precooling temperature (TL) is reached (YES in step S3), control unit 40 advances the process to step S4.
In step S <b> 4, the control unit 40 stops timing by the timer unit 44. At this time, data at time b measured by the timer unit 44 of the control unit 40 is stored in the storage unit 46.

In step S5, the control unit 40 stops the temperature control of the low temperature tank 20. Specifically, the drive of the refrigerator 24 is temporarily stopped by the control signal of the refrigerator 24 accompanying the preliminary activation output from the output unit 48.
When the low temperature bath temperature (B) of the low temperature bath 20 reaches the precooling temperature (TL) in step S6, the calculation unit 42 of the control unit 40 sets the time (b) when the precooling temperature (TL) is reached from the time a at the time of preliminary activation. : Hereinafter, the elapsed time (time a to time b) until the precooling temperature arrival time is read from the storage unit 46, and the temperature gradient α (α = (C−TL ° C.), which is the amount of temperature change per unit time. ) / (B−a)) is calculated (Formula 1).
[Equation 1]
α = (C−TL) / (b−a)
Here, the low temperature test temperature (C) indicates a preset temperature of the gas (atmosphere) during the low temperature test, and the previous low temperature test temperature (C) is time a (a: low temperature test start, high temperature test end time. The low temperature test temperature (C) set as the temperature data is adopted using the fact that it is the same temperature as the starting point of the temperature change of the low temperature bath temperature B at the time of the preliminary start in accordance with the low temperature bath temperature B in This simplifies data collection by detecting the temperature of the gas in the cryostat 20.
In the next step S7 and step S8, the control unit 40 calculates timing for resuming the low temperature test (end of the high temperature test).

That is, in step S7, the calculation unit 42 calculates the precooling recovery required time (ed) from the low temperature bath temperature (B) and the calculated temperature gradient α. The low temperature bath current temperature (Bn) is a temperature at the current time (for example, Bn = B1 at the time d1), and is used for calculating the temperature gradient α. For this reason, the time required for precooling recovery (ed) is such that the low temperature tank temperature (B1: the low temperature tank temperature at time d1) reaches the precooling temperature (TL) when the refrigerator 24 is restarted at the current time d1. It will be time to do.

In step S <b> 8, it is determined whether or not it is time to resume the temperature control of the cryostat 20 and perform the low temperature test. The expected temperature stabilization time (ge) is obtained using the time g at which the low temperature test is resumed and the precooling recovery time (ed) predicted from the current time d.
Further, the minimum temperature stabilization time (g−f) falls within a predetermined range from the precooling temperature (TL) by decreasing the vertical movement of the temperature after the low temperature bath temperature (B) reaches the precooling temperature (TL). Therefore, the buffer time until a state suitable for a low-temperature test is obtained is assumed to be determined by experiments and simulations.

The control unit 40 calculates the time e when the current low temperature bath temperature B reaches the precooling temperature (TL) using the calculated precooling return required time (ed). In addition, an expected temperature stabilization time (g−e) indicating a period from the arrival time e to the start of the current low temperature test is calculated. In addition, the minimum temperature stabilization time (g−f) required for stabilizing the temperature before the start of the current low temperature test is calculated.

Then, the temperature stabilization minimum time (g-f) required until the current low temperature test is started and the predicted temperature stabilization time (ge) are compared.
By executing such calculation at any time in the calculation unit 42 of the control unit 40, the low temperature bath temperature (B) falls within a predetermined range centered on the precooling temperature (TL), and is the fastest in a stable state. The restart timing of the refrigerator 24 is calculated.

That is, in step S8, the control unit 40 determines that the minimum temperature stabilization time (g-f) is longer than the expected temperature stabilization time (ge) and has not yet reached a time suitable for return (step S8). If NO in S8, the process returns to step S7, the precooling recovery required time (ed) is calculated by the calculation unit 42, and the processes in steps S7 and S8 are performed again.
When the minimum temperature stabilization time (g-f) has reached the expected temperature stabilization time (ge) (YES in step S8), the control unit 40 proceeds to step S9 to execute the expected temperature stabilization time. The refrigerating machine 24 is restarted at a coincidence time so that (ge) does not become shorter than the minimum temperature stabilization time (g-f).

As described above, the environmental test apparatus 1 according to the first embodiment temporarily stops the temperature control of the low temperature tank 20 after acquiring the data of the temperature gradient α of the precooling operation by the preliminary activation simultaneously with the start of the current high temperature test. Even when the temperature of the low temperature chamber 20 rises due to the stop of the temperature control, for example, the optimum restart timing according to the test conditions is automatically calculated with high accuracy using the current low temperature chamber temperature (B).

As a result, during the pre-cooling operation, it is possible to stop the driving of the refrigerator 24 and the low-temperature tank side heater 26 that have been maintained in the pre-cooling state by driving for a relatively long time, thereby improving energy efficiency. Can do.
In addition, before the low temperature test is performed, when the refrigerator 24 is preliminarily started and the low temperature tank 20 is precooled to the precooling temperature (TL), the low temperature tank side blower 52 is driven so that the low temperature tank 20 is precooled. Can be circulated, and further, the calculation accuracy of the temperature gradient α can be improved, and the refrigerator 24 can be restarted at the optimum timing according to the test conditions.

And the temperature gradient (alpha) is obtained using the data at the time of the preliminary starting collected at the time of the start of the high temperature test in the same temperature cycle (step S6), and the control part 40 is the time required for precooling return (ed) by the calculating part 42. And the temperature stabilization minimum time (g−f) are repeated (steps S7 and S8).
For this reason, the control unit 40 can restart the operation of the refrigerator 24 when the calculated scheduled return time coincides with the low temperature test start time, and can cool the low temperature tank 20 to the precooling temperature (TL) at an optimal timing.

Moreover, under the test conditions in which the required time per one temperature cycle is long, the influence on the calculation accuracy for predicting the restart timing of the refrigerator 24 may be further increased. However, the environmental test apparatus 1 according to the first embodiment acquires data of the temperature gradient α used for the precooling operation simultaneously with the start of the high temperature test performed within the same temperature cycle as that of the current low temperature test.
For this reason, since data is acquired in the same temperature cycle as the pre-cooling operation and at the beginning of the same low temperature test, compared to the conventional one where the time from data acquisition to utilization exceeds one temperature cycle, Less time has passed. Therefore, it becomes difficult to be affected by the amount of heat entering the low-temperature tank 20 from the surroundings and the change in the frosting state of the refrigerator 24, and the prediction accuracy of the timing of the precooling state can be improved.

Then, as in the conventional example, maintaining the temperature of the low temperature tank 20 at the precooling temperature (TL) during the entire period during which the high temperature test is performed increases the start-up time of the refrigerator 24 and the low temperature tank side heater 26. This may cause unnecessary start-up, and it is difficult to say that energy efficiency is good.

On the other hand, in the environmental test apparatus 1 of the first embodiment, the control unit 40 performs the precooling operation for preliminarily starting the refrigerator 24 and calculating the temperature gradient α at the start of the high temperature test within the same temperature cycle. When the pre-cooling temperature (TL) is reached after performing the corresponding operation, the refrigerator 24 is temporarily stopped.
For this reason, it is not necessary to start the refrigerator 24 until immediately before this low temperature test CL is started, and the low temperature tank heater 26 is not started, so that energy efficiency is good.
Further, when data is collected during the previous temperature cycle, there is a risk of frost forming around the refrigerator 24 that is activated during the low temperature test. However, the environmental test apparatus 1 according to the first embodiment has the same temperature cycle. Since the refrigerator 24 is preliminarily started at the start of the high temperature test, the possibility of frost formation can be reduced. In addition, since the refrigerator 24 is preliminarily activated in a relatively short time, new frost formation is suppressed, and the influence of changes in disturbance factors can be reduced.

FIG. 4 is a time chart showing how the refrigerator 24 once stopped is restarted at any point during the high temperature test in the environmental test apparatus 1 of the first embodiment.
The time chart of FIG. 4 shows a test mode of a so-called two-zone cycle (a high temperature test zone and a low temperature test zone) in which the low temperature test CL and the high temperature test are alternately repeated with a time cycle from time a to time i as one temperature cycle C1. ing.
Here, the vertical axis represents temperature (T), and the horizontal axis represents time (H). The test bath temperature (A) in one temperature cycle C1 is equal to the high temperature bath temperature (not shown) during the high temperature test (time a to time g), and during the low temperature test CL (time g to time i) A state of changing to be equal to the temperature (B) is shown.

The time chart of FIG. 4 of the environmental test apparatus 1 will be described in order of time with reference to FIGS. 1 and 2. First, the low temperature test CL of the previous temperature cycle C0 is executed until time a. Therefore, the test tank temperature (A) is the same constant low temperature test temperature (C) as the low temperature tank temperature (B).
Next, the current temperature cycle C1 is started. At the time a when the high temperature test of the current temperature cycle C1 is started, the low temperature test CL of the previous temperature cycle C0 is completed. The ports 28 and 29 are blocked by the low-temperature side blowing opening / closing damper 50 and the low-temperature side suction opening / closing damper 51, and cooling of the low-temperature tank 20 is started.

At this time, immediately after the end of the low temperature test CL of the previous temperature cycle C0 and at the start of the current high temperature test CH, the low temperature bath temperature (B) becomes a constant low temperature test temperature (C). Yes. Therefore, the low temperature bath temperature (B) at time a can be easily collected from the preset data of the low temperature test temperature (C) in the storage unit 46.
By the preliminary start-up of the refrigerator 24, the low-temperature tank temperature (B) of the low-temperature tank 20 decreases to the pre-cooling temperature (TL). When reaching the precooling temperature (TL) at time b, the control unit 40 stops the refrigerator 24 and starts calculating the temperature gradient α. The temperature gradient α indicates the time until the cryocooler 20 reaches the precooling temperature (TL) after the preliminary start of the refrigerator 24 at the end of the previous low temperature test CL, and the low temperature bath temperature ( B) and the temperature difference between the precooling temperature (TL) are used for calculation.

In the first embodiment, as described above, when calculating the time e1 to reach the precooling temperature (TL) from the time d at which the precooling is resumed, immediately after the previous low temperature test and immediately after the high temperature test is started. During the preliminary start-up, data on the temperature gradient α described later is collected. Since the data of the temperature gradient α is data collected in the same temperature cycle C1 as that of the low-temperature test to be precooled, the optimum restart timing can be calculated with higher accuracy.
When the refrigerator 24 is stopped at time b, the low temperature chamber temperature (B) starts to gradually increase due to heat entering from the outside of the low temperature chamber 20, and the refrigerator 24 is restarted for precooling. Thus, at the time d1 when the temperature control of the low temperature tank 20 is resumed, the temperature (B1) is higher than the precooling temperature and lower than the low temperature test temperature (C).

The low temperature bath temperature (B) of the low temperature bath 20 is reduced to the precooling temperature (TL) at the time e1 by restarting the refrigerator 24 at the time d1, and the precooling operation is started.
From time e1 to time g when the low temperature test is started is a pre-cooling operation period. The pre-cooling operation period is a period in which the low-temperature tank temperature (B) of the low-temperature tank 20 is maintained at the pre-cooling temperature (TL) by the restarted refrigerator 24 and the low-temperature tank side heater 26. As the pre-cooling operation period (time e1 to time g) is shorter, the start-up time of the refrigerator 24 and the start-up of the low-temperature tank heater 26 can be reduced, and the thermal efficiency can be improved.

In the first embodiment, as described above, the temperature gradient α and the current low temperature bath temperature (B1) during the high temperature test are used, and the time required for the precooling recovery (ed) is calculated by the calculation unit 42. Can continue. As a result, even when the low-temperature bath temperature (B) fluctuates in the vertical and low-temperature directions due to disturbance factors, it is possible to calculate the time e1 at which the accurate precooling temperature (TL) that is always required is reached.

At time g, the low temperature test CL is started in the current temperature cycle C1. When the low temperature test is performed, a temperature stabilization minimum time (g-f) in which the precooling temperature (TL) is continued for a certain period is secured in advance. For this reason, the low temperature test CL can be started from the precooling temperature (TL) of the low temperature bath 20 which is always stable, and the test reliability of the environmental test apparatus 1 can be improved.

When the low temperature test is started at time g, the control unit 40 performs the low temperature operation by driving the refrigerator 24, the low temperature tank side heater 26, the low temperature tank air blower 27, and the high temperature tank side heater 36 (time g). ~ Time i).

When the end of the low temperature test CL ends at time i and the low temperature operation is stopped, the next temperature cycle C2 is started. In the temperature cycle C2, similarly to the temperature cycle C1, the high temperature test CH and the low temperature test CL are performed, and thereafter, the high temperature test CH and the low temperature test CL of a plurality of temperature cycles (not shown) are alternately performed.

FIG. 5 is a time chart showing a state in which the minimum temperature stabilization time (g−f) is not ensured due to a delay in restart in the environmental test apparatus of the first embodiment.
The difference from FIG. 4 will be mainly described. The low temperature bath temperature (B) of the low temperature bath 20 calculated from the current time d2 and the precooling recovery required time (ed) is the precooling temperature (TL) at the time e2. ).

However, if the expected temperature stabilization time (g−e2) reaches and exceeds the minimum temperature stabilization time (g−f) (time d2), the minimum temperature stabilization time (g−f) until the restart time g. As a result, it is difficult to guarantee testability. That is, when the restart timing reaches time d2 and rises to the low temperature bath temperature (B1), there is a possibility that appropriate precooling cannot be performed.

First, the control unit 40 of the first embodiment uses the calculated precooling recovery required time (ed) to set the current low temperature bath temperature (B) of the low temperature bath 20 to a stable precooling temperature (TL). The expected temperature stabilization time (g−e2) from when it reaches to when this low-temperature test is started is calculated.
Then, the control unit 40 compares the low-temperature bath temperature (B) with the pre-cooling temperature (TL) and compares it with the minimum temperature stabilization time (g−f) required until the current low-temperature test is started. . By comparison, the control unit 40 restarts the refrigerator 24 at the coincident timing so that the expected temperature stabilization time (g−e2) does not cut the minimum temperature stabilization time (g−f).

For this reason, when restarting the refrigerator 24, the control part 40 can ensure the minimum temperature stabilization time (g-f) and can stabilize the low temperature tank temperature (B), and this time low temperature test Reliability can be improved.

FIG. 6 is a time chart showing how the refrigerator 24 is restarted when the expected temperature stabilization time coincides with the temperature stabilization minimum time in the environmental test apparatus 1 of the first embodiment.
In FIG. 6, when the expected temperature stabilization time (g−e3) reaches the minimum temperature stabilization time (g−f) (time d3), the control unit 40 restarts the refrigerator 24 and starts the precooling operation. To do.

For this reason, the expected temperature stabilization time (g−e3) coincides with the minimum temperature stabilization time (g−f) (time e = time f), and the timing (g−f) necessary for cooling can be ensured ( The refrigerator 24 can be restarted at time d).
Moreover, since it can be in the state suitable for a low temperature test by the time g when a low temperature test is started, the control part 40 does not restart the refrigerator 24 until the time d just before a low temperature test starts.

The refrigerator 24 that has been preliminarily activated at time a is stopped at time b when the low temperature bath temperature (B) reaches the precooling temperature (TH). For this reason, between time b and time d3, heat moves between the gas in the cryogenic bath 20 and the constituent members. The temperature of the constituent members such as the walls of the cryostat 20 becomes a state approaching the temperature of the cryostat temperature sensor 22 at the time of restart as time elapses, and the low temperature test is started.
Therefore, the separation between the low temperature chamber temperature sensor 22 and the surrounding constituent members at the start of the low temperature test is reduced, and the test accuracy can be further improved.

(Second Embodiment)
7 to 10 show an environmental test apparatus 101 according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected and demonstrated about the same thru | or equivalent part as the environmental test apparatus 1 of the said 1st Embodiment.

FIG. 7 is a schematic diagram illustrating the configuration of the environmental test apparatus 101 according to the second embodiment. First, the difference in configuration from the environmental test apparatus 1 of the first embodiment shown in FIG. 1 will be described. This environmental test apparatus 101 is a low-temperature side mechanical that opens and closes the vent holes 28 and 29 of the low-temperature tank blower 127. Dampers 150 and 151 are provided. The low temperature side mechanical dampers 150 and 151 are provided in place of the low temperature side blowing opening / closing damper 50 and the low temperature side suction opening / closing damper 51 of the first embodiment, and passively controlled by wind pressure according to on / off control of the low temperature tank side blower 52. Ventilation openings 28 and 29 are provided to be openable and closable.

Further, the environmental test apparatus 101 includes high temperature side mechanical dampers 160 and 161 that open and close the ventilation ports 38 and 39 of the high temperature bath air blower 137. The high temperature side mechanical dampers 160 and 161 are provided in place of the high temperature side blowout opening / closing damper 60 and the high temperature side suction opening / closing damper 61 of the first embodiment, and the high temperature side mechanical dampers 160 and 161 are turned on. The ventilation openings 38 and 39 are provided to be openable and closable in accordance with the off control.

Furthermore, in the environmental test apparatus 101 of the second embodiment, external ventilation ports 180 and 181 that communicate the space in the test tank 10 and the external space are formed in the wall of the test tank 10.
The external ventilation openings 180 and 181 are provided with normal temperature dampers 170 and 171 for opening and closing the ventilation openings 38 and 39 of the low-temperature tank blowing section 127, respectively. These room temperature dampers 170 and 171 are opened in a state where a room temperature test is performed in a test mode of a so-called three-zone cycle (a high temperature test zone, a room temperature test zone, and a low temperature test zone), and a low temperature test and a high temperature test are performed. It is configured to be closed in a closed state.

The time charts shown in FIGS. 8 to 10 shown below implement a so-called three-zone cycle (high temperature test zone, normal temperature test zone, low temperature test zone) test mode that repeats from time a to time i as one temperature cycle C3. It shows how they are doing.

FIG. 8 is a time chart showing a state in which the stopped refrigerator 24 is restarted at any point during the high temperature test. The room temperature test CM1 is started from time a when the previous low temperature test CL is completed. In the normal temperature test CM1, the low temperature side mechanical dampers 150 and 151 of the environmental test apparatus 101 shown in FIG. 7 are closed, and the external ventilation openings 180 and 181 are opened by the normal temperature dampers 170 and 171. Thereby, the gas in the test chamber 10 communicates with external air via the external ventilation ports 180 and 181. The test chamber temperature (A) starts to rise and reaches the same room temperature D as the outside. During the normal temperature test, the test bath temperature (A) is maintained at the normal temperature (D) until the high temperature test CH is started.

When the high temperature test CH is completed, the normal temperature test CM2 and the low temperature test CL are repeated again, so that the low temperature test, the normal temperature test, and the high temperature test are repeated with the one time cycle C3 from the time a to the time i. High temperature test zone, normal temperature test zone, and low temperature test zone) are performed.

In the environmental test apparatus 101 according to the second embodiment, the low temperature side mechanical dampers 150 and 151 are closed from time a to time g, and the low temperature tank 20 and the test tank 10 are disconnected.
For this reason, the temperature gradient α for calculating the time d at which the precooling operation is started during the low temperature test CL within the same temperature cycle C3 is changed from the time a at which the previous low temperature test CL is completed to the time b at which the precooling temperature TL is reached. It can be calculated using the temperature difference.

As shown in FIG. 8, for example, depending on the setting of the restart time d4 of the refrigerator 24, the expected temperature stabilization time (g−e4) does not reach the minimum temperature stabilization time (g−f), and from the time e4. The precooling temperature TL must be maintained for a relatively long time until time g. For this reason, the start-up time of the refrigerator 24 and the start-up of the low-temperature tank side heater 26 increase, and the thermal efficiency decreases.

In the time chart shown in FIG. 9, in the environmental test apparatus 101 of the second embodiment, a condition (time e5 = time) that the expected temperature stabilization time (g−e5) and the minimum temperature stabilization time (g−f) match. The refrigerator 24 is restarted at time d5 which is f).
In the second embodiment, a so-called three-zone cycle test mode is implemented, and even if one temperature cycle C3 is set relatively long by adding room temperature tests CM1 and CM2, etc., a spare in the same temperature cycle C3 is used. The temperature gradient α can be calculated by activation (time a to time b). For this reason, in addition to the effect of 1st Embodiment, the optimal restart time d5 according to test conditions can be automatically calculated accurately.

The time chart shown in FIG. 10 shows that in the environmental test apparatus 101 of the second embodiment, the restart time d6 is delayed and the expected temperature stabilization time (g−e6) has passed the minimum temperature stabilization time (g−f). Yes. Even if the control unit 40 restarts the refrigerator 24 at time d6, it reaches the precooling temperature at time e6, and the temperature stabilization minimum time (gf) is not sufficiently secured.

The control unit 40 of the environmental test apparatus 101 according to the second embodiment determines that the expected temperature stabilization time (g−e6) matches the minimum temperature stabilization time (g−f) (time e6 = time f), and the necessary precooling time. The refrigerator 24 is restarted at time d5 when (g−f) can be secured. For this reason, when restarting the refrigerator 24, the minimum temperature stabilization time (g-f) can be secured to stabilize the low-temperature bath temperature (B), and the test reliability of this low-temperature test is improved. be able to.

Further, the room temperature dampers 170 and 171 of the environmental test apparatus 101 of the second embodiment close the external ventilation openings 180 and 181 so that the two-zone cycle (high temperature test) is performed similarly to the environmental test apparatus 1 of the first embodiment. Zone, low-temperature test zone) test mode. When performing the two-zone cycle test mode, the test reliability can be improved by obtaining the temperature gradient α using the current low temperature test and the data collected at the start of the high temperature test within the same temperature cycle. it can.

As described above, according to the environmental test apparatuses 1 and 101 in the first and second embodiments, at the start of the high temperature test in the same temperature cycle C1 or C3, the control unit 40 preliminarily starts the refrigerator 24 to The gradient α is calculated. For this reason, the optimal restart timing according to the test conditions can be automatically calculated accurately.
Furthermore, according to the environmental test apparatus 101 of the second embodiment, the two-zone cycle (high temperature test zone, low temperature test zone) test mode is implemented and the three zone cycle (high temperature test zone, normal temperature test zone, low temperature test zone). ) In the test mode can be changed according to the test conditions.

In addition, even in a test in which one temperature cycle including a low temperature test, a normal temperature test, or a high temperature test takes a long time, measurement accuracy is reduced by reducing the influence on the prediction accuracy of the operation timing of the equipment, such as the restart timing of the refrigerator 24. Can be improved.
Other configurations and operational effects are the same as or equivalent to those of the first embodiment, and thus the description thereof is omitted.

[Modification]
The present invention is not limited to the above-described embodiments, and various modifications can be made. The above-described embodiments are illustrated for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Further, it is possible to delete a part of the configuration of each embodiment, or to add or replace another configuration. Examples of possible modifications to the above embodiment are as follows.

In each of the above embodiments, in the configuration of the environmental test apparatus 1 shown in FIG. 1, the low temperature side blowing opening / closing damper 50 and the low temperature side suction opening / closing damper 51 are opened and closed in synchronization with the drive control of the low temperature tank side blower 52. However, as long as the low-temperature tank side blower 52 is driven and stopped, the gas between the test tank 10 and the low-temperature tank 20 (or the high-temperature tank 30) is circulated and cut off. The air blower may be used.

  3 has been described as a software process using a program executed by the control unit 40 shown in FIG. 2 in the above embodiment, but part or all of the process is shown in ASIC (Application Specific An integrated circuit (IC for specific application) or a hardware process using an FPGA (field-programmable gate array) may be used.

[Overview of composition and effect]
As described above, according to the environmental test apparatus in the embodiment, at the start of the high temperature test within the same temperature cycle, the control unit 40 preliminarily starts the refrigerator 24 and calculates the temperature gradient α. For this reason, the optimal restart timing according to the test conditions can be automatically calculated accurately.

Moreover, the control part 40 of the environmental test apparatus 1 is calculating sequentially about the time e1 using the current temperature of the low temperature tank 20 with respect to the time e1 about the time e1 which reaches precooling temperature (TL) during precooling. The temperature gradient α, which is the basis for the calculation, is collected using the preliminary start of the low temperature test CL that is started at the same time when the high temperature test CH is started within the same temperature cycle C1. For this reason, the optimal restart timing can be calculated with higher accuracy.

Then, by continuously calculating the precooling recovery time (ed) using the temperature gradient α and the current low temperature bath temperature (B1) in the high temperature test CH, the low temperature bath temperature (B) is calculated. Even if it fluctuates in the high and low temperature directions due to disturbance factors, the time e1 at which the precooling temperature (TL) is reached is recalculated from the time d1 at which accurate precooling starts immediately.

In addition, the control unit 40 uses the calculated precooling recovery required time (ed), and this time after the low temperature bath temperature (B) of the current low temperature bath 20 reaches a stable precooling temperature (TL). It is necessary to calculate the expected temperature stabilization time (g−e2) until the low-temperature test is started and to stabilize the low-temperature bath temperature (B) at the pre-cooling temperature and to start the low-temperature test. Compared to the minimum temperature stabilization time (gf) to be performed. By comparison, the control unit 40 determines that the expected temperature stabilization time (g−e2) and the temperature stabilization minimum time (g−e−2) do not exceed the temperature stabilization minimum time (g−f). The refrigerator 24 is restarted at the timing when f) matches.

For this reason, when the refrigerator 24 is restarted, the temperature stabilization minimum time (g−f) can be secured to stabilize the low temperature bath temperature (B), and the test reliability of the current low temperature test can be further improved. Can be improved.

DESCRIPTION OF SYMBOLS 1,101 Environmental test apparatus 10 Test tank 12 Test tank temperature sensor 20 Low temperature tank 22 Low temperature tank temperature sensor 24 Refrigerator 26 Low temperature tank side heater 27, 127 Low temperature tank air blower 28, 29, 38, 39 Ventilation opening 30 High temperature tank 32 High temperature bath temperature sensor 36 High temperature bath heater 37, 137 High temperature bath blower 40 Control unit 41 Input unit 42 Calculation unit 44 Timer unit 46 Storage unit 48 Output unit 50 Low temperature side blowing open / close damper 51 Low temperature side suction open / close damper 52 Low temperature bath side Blower 54, 55, 64, 65 Actuator 60 High temperature side blow open / close damper 61 High temperature side suction open / close damper 62 High temperature tank side blower 70 DUT 150, 151 Low temperature side mechanical damper 160, 161 High temperature side mechanical damper 170, 171 High temperature damper 180 , 181 External vent

Claims (4)

A test chamber for placing the DUT;
A low temperature bath communicating with the test bath;
A refrigerator that cools the gas in the low-temperature tank to a precooled state;
A high-temperature bath communicating with the test bath;
A high-temperature tank heater for heating the gas in the high-temperature tank to a preheated state;
The pre-cooled gas in the low-temperature chamber or the pre-heated gas in the high-temperature chamber is sent around the object to be tested arranged in the test chamber, and the high-temperature test and the low-temperature test are performed. An air blower that alternates as a temperature cycle; and
During the high-temperature test within the same temperature cycle as the current low-temperature test, the refrigerator is pre-started and the temperature gradient is calculated from the elapsed time until the low-temperature tank reaches the pre-cooling temperature and the temperature change. An environmental test apparatus comprising: a control unit that restarts the machine so that the low temperature bath is in a precooled state based on the temperature gradient and before the start of the low temperature test.   When calculating the temperature gradient, the control unit preliminarily starts the refrigerator at the end of the previous low temperature test, the time until the low temperature tank reaches the precooling temperature, and the time when the precooling operation is started. The environmental test apparatus according to claim 1, wherein the temperature difference between the low temperature bath temperature and the precooling temperature is used.   The environmental test apparatus according to claim 2, wherein the control unit calculates a time required for pre-cooling recovery using the temperature gradient and the current low temperature bath temperature.   The controller uses the calculated precooling recovery time to calculate an expected temperature stabilization time from when the current low temperature bath reaches a stable precooling temperature until the current low temperature test is started. The predicted temperature stabilization time is the minimum temperature stabilization time compared to the minimum temperature stabilization time required until the low temperature bath temperature is stabilized at the precooling temperature and the current low temperature test is started. The environmental test apparatus according to claim 3, wherein the refrigerator is restarted so as not to cut off.

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