JPH06123688A - Temperature returning time controller - Google Patents

Abstract

PURPOSE:To set returning time arbitrarily. CONSTITUTION:A high-temperature bath temperature sensor 21, a low- temperature bath temperature sensor 22, and a test bath temperature sensor 23 are provided in a high-temperature bath, a low-temperature bath, and a testing bath, respectively. Time until the temperature of the testing bath reaches a preset high temperature after initiation of a high-temperature bleaching and time until it reaches a preset low temperature from initiation of a low- temperature bleaching are set by a setting means 31. Then, a control part 32 counts each time and then changes the pre-heating temperature of the high- temperature bath or the pre-cooling temperature of the low-temperature bath, if each counted time differs from a set value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an environment test apparatus for testing the reliability of a sample under temperature change stress by exposing the sample such as an electronic component to a high temperature atmosphere and a low temperature atmosphere. The present invention relates to a temperature recovery time control device capable of arbitrarily setting the reaching time to the exposure temperature.

[0002]

2. Description of the Related Art Conventionally, in order to test reliability against stress due to temperature change of electronic parts and printed circuit boards on which electronic parts etc. are mounted, these test pieces are alternately exposed to high temperature and low temperature atmospheres. Environmental tests such as impact tests are carried out.

Generally, the thermal shock test is carried out by using a thermal shock device equipped with a high temperature tank, a low temperature tank and a test tank to rapidly raise and lower the ambient temperature of the sample placed in the test tank. For this reason, the high temperature tank is maintained at the preheating temperature during periods other than the high temperature exposure, and the low temperature tank is maintained at the precooling temperature during periods other than the low temperature exposure.

FIG. 7 is a diagram showing a general temperature transition in a thermal shock test. In the figure, TP _H is the high temperature bath temperature, TP _L is the low temperature bath temperature, TP _T is the test bath temperature, TP _HS is the preheat temperature, TP _H0 is the high temperature set temperature, TP _AT is the ambient temperature, and TP _L0
Is the low temperature exposure set temperature, TP _LS is the precooling temperature, ΔTP _OS is the overshoot amount, ΔTP _US is the undershoot amount, t _T is the time until the temperature of the test tank first reaches the high temperature or low temperature exposure set temperature (hereinafter, It is called return time). Here, the recovery time t _T depends on the amount of the sample, the preheating temperature of the high temperature tank and the precooling temperature of the low temperature tank. Therefore, in the conventional thermal shock device, the user arbitrarily sets the preheating temperature and the precooling temperature so that the recovery time is shortened.

On the other hand, a thermal shock device has also been proposed which automatically sets the preheating and precooling temperatures so that the recovery time becomes a predetermined time or less (Japanese Patent Laid-Open No. 3-214037).

[0006]

However, depending on the sample to be tested, there are cases where it is desired to extend or further shorten the recovery time.

For example, in order to obtain data compatible with past experimental data obtained by a thermal shock device having a small heating and cooling capacity, it is necessary to lengthen the recovery time.

For this purpose, however, in the conventional thermal shock device, the optimum preheating and precooling temperatures must be determined by conducting preliminary tests a plurality of times at different preheating and precooling temperatures and measuring the recovery time. I had to do it.

Further, the apparatus described in Japanese Patent Laid-Open No. 31403/1990 is designed to set the recovery time to a predetermined time or less, and there is no disclosure about obtaining an arbitrary recovery time.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a temperature recovery time control device capable of arbitrarily setting the recovery time.

[0011]

In order to achieve the above object, the present invention comprises a preparation tank and a test tank having different preparation temperatures, and the preparation tank and the test tank are connected to each other and placed in the test tank. In an environmental testing device that applies temperature change stress by exposing the DUT to an atmosphere of a preset temperature, a preparation tank temperature detection means provided in the preparation tank,
Test tank temperature detecting means provided in the test tank, setting means for setting the arrival time from the start of exposure until the temperature of the test tank reaches the preset temperature, and measuring the arrival time And a comparing means for comparing the timed arrival time and the set time, and when the timed arrival time is shorter than the set time, the preparatory temperature of the preparatory tank is the preset temperature. And a temperature changing means for separating the preparatory temperature of the preparatory tank from the preset temperature when the measured arrival time is longer than the preset time.

[0012]

According to the present invention, the preparation temperature is brought close to the preset temperature when the time from the start of exposure to the temperature of the test tank reaching the preset temperature is shorter than the preset time. On the other hand, when it is longer than the set time, the preparation temperature is separated from the preset temperature.

[0013]

FIG. 2 is a schematic configuration diagram of a thermal shock device as an example of an environmental test device to which the present invention is applied. The thermal shock device comprises a high-temperature tank 1, a low-temperature tank 2 and a test tank 3 which are adiabatically partitioned, and a high-temperature tank partition 6a, a high-temperature inlet 6b and a high-temperature outlet are provided between the high-temperature tank 1 and the test tank 3. 6c,
The low temperature tank 2 and the test tank 3 can communicate with each other through a low temperature inlet 6d and a low temperature outlet 6e. The outside airflow inlet 6g and the outside airflow outlet 6f circulate the air outside the apparatus in the normal temperature exposure mode. The shelf 4 is arranged in the test tank 3, and the sample 5 is placed on the shelf 4 so that the thermal shock test can be performed.

The high temperature tank heater 11 raises the temperature of the air in the high temperature tank 1. The fan 12a is the high temperature tank 1.
It convects the air inside and is designed to always operate. A multi-blade fan or the like is used as the fan 12b, which sucks in the air in the front (on the left side in the drawing) and blows it out toward the high temperature inlet 6, and operates in the high temperature exposure mode and the normal temperature exposure mode. It has become.

The refrigerator 13 lowers the air temperature in the low temperature tank 2. The low temperature tank heater 14 is for temperature control, and the low temperature tank heater 14 is kept operating while the refrigerator 13 is constantly driven.
By turning on and off, the air temperature is accurately and stably controlled. Also, the low temperature tank heater 1
4 is for defrosting the refrigerator 13. The regenerator 15 is for reducing the load on the refrigerator 13. A multi-blade fan or the like is used for the fan 12c,
Low temperature inlet 6d by sucking air from the front (left side in the figure)
It blows out toward and is always active.

The dampers 16a to 16f have openings 6a to 6f, respectively.
The opening / closing state of g is switched to control the circulation of air in the thermal shock device. The damper 16a switches between opening and closing of the high temperature tank partition 6a and the outside airflow inlet 6g. When in the high temperature exposure mode, the high temperature tank partition 6a is "open" (outside airflow inlet 6g is "closed") and at room temperature exposure mode. Alternatively, in the low temperature exposure mode, the high temperature tank partition 6a is "closed" (the outside air inlet 6g is "open").

The damper 16b switches the opening and closing of the high temperature inlet 6b, and is "open" in the normal temperature exposure mode or the high temperature exposure mode and "closed" in the low temperature exposure mode. The damper 16c switches opening and closing of the high temperature outlet 6c, and is "open" in the high temperature exposure mode and "closed" in the normal temperature exposure mode or the low temperature exposure mode.

The damper 16d switches the opening and closing of the low temperature inlet 6d, and is "closed" in the normal temperature exposure mode or the high temperature exposure mode and "open" in the low temperature exposure mode. The damper 16e switches opening and closing of the low temperature outlet 6e, and is "closed" in the normal temperature exposure mode or the high temperature exposure mode, and "open" in the low temperature exposure mode.

The damper 16f switches opening / closing of the outside airflow outlet 6f, and is "open" in the normal temperature exposure mode.
It is designed to be "closed" in the low temperature exposure mode or the high temperature exposure mode.

That is, FIG. 2 shows the states of the dampers 16a to 16f in the normal temperature exposure mode.

The high temperature tank temperature sensor 21 is arranged in the high temperature tank 1 and near the high temperature outlet 6c, and detects the air temperature in the high temperature tank 1. The low temperature tank temperature sensor 22 is
It is arranged in the low temperature tank 2 and near the low temperature outlet 6e, and detects the air temperature in the low temperature tank 2.

The test tank leeward temperature sensor 23 is arranged on the windward side of the air circulation inside the test tank 3 (on the right side in the drawing), and the test tank leeward temperature sensor 24 is on the lee side of the air circulation inside the test tank 3. It is arranged on the left side in the drawing and detects the air temperature in the test tank 3, respectively.

The ambient temperature sensor 25 is arranged at an appropriate place on the surface of the thermal shock device and detects the ambient temperature of the device.

It should be noted that the conditions and the temperature sensors 21 to 21 set by the setting means 31 are provided at appropriate positions on the surface of the thermal shock device.
A display unit is provided for numerically or graphically displaying the temperature of each tank detected at 24, the current cycle number, and the like.

FIG. 3 is a schematic configuration diagram of the thermal shock device showing the states of the dampers 16a to 16f and the circulation direction of the air in the device. (A) shows the high temperature exposure mode state, (b) shows the low temperature exposure mode state. Shows.

FIG. 1 is a block diagram showing a control configuration of a thermal shock device as an example of an environment test device to which the present invention is applied. The setting means 31 is composed of a numeric keypad or the like and is used to set and input the test conditions of the thermal shock test, and the high temperature exposure temperature, the low temperature exposure temperature, the recovery time, the number of cycles of the thermal shock, two zones (for example, the high temperature exposure mode → Low temperature exposure mode-> high temperature exposure mode repeated or selection of 3 zones (for example, high temperature exposure mode-> normal temperature exposure mode-> low temperature exposure mode-> normal temperature exposure mode-> high temperature exposure mode), sensor for detecting temperature of test tank 3 Selection (upwind temperature sensor 23 or downwind temperature sensor 24 of the test tank), time of each exposure mode, etc. are set.

The sequence controller 33 receives the signal input from the control unit 32, which will be described later, and receives the signal from the fan 12a.
-12c, dampers 16a-16f, high temperature tank heater 11,
It controls the operations of the refrigerator 13, the low temperature tank heater 14, and the like. Here, the temperature control system employs PID control. In order to shorten the recovery time, until it approaches the set temperature exposure temperature TP _T of the test chamber 3 from the start of exposure mode is interrupted PID control.

Further, the sequence controller 33 operates the selecting means 321 and 322 described later in accordance with the test mode to select the temperature sensor to be used.

The control section 32 is composed of a microcomputer or the like and controls the operation of the entire apparatus, and comprises selection means 321, 322, timing means 323, comparison means 324, temperature change means 325 and the like.

Further, the control unit 32 calculates the initial values of the preheating temperature of the high temperature tank 1 and the precooling temperature of the low temperature tank 2 based on the set exposure temperatures of the high temperature and the low temperature.

The selecting means 321 outputs the output of the high temperature tank temperature sensor 21 in the high temperature exposure mode and the output of the low temperature tank temperature sensor 22 in the low temperature exposure mode to the temperature changing means 325 according to the operation signal from the sequence controller 33. It is a thing.

The selecting means 322 outputs the output of the test tank lee temperature sensor 23 or the test tank lee temperature sensor 24 selected by the setting means 31 to the time measuring means 323 according to the operation signal from the sequence controller 33. .

The time counting means 323 measures the return time. The comparison means 324 is for comparing the actual recovery time with the recovery time set by the setting means 31. The temperature changing means 325 updates the values of the preheating temperature and the precooling temperature based on the comparison result by the procedure described later. When the recovery time set by the updated values operates, these values are stored in the built-in memory of the control unit 32.

Next, the calculation of the initial values of the preheating temperature and the precooling temperature will be described. The preheating temperature and the precooling temperature are different when the exposure mode is changed from high temperature exposure to low temperature exposure.
Since the required temperature is different when using the normal temperature exposure mode such as high temperature exposure → normal temperature exposure → low temperature exposure, these initial values require two types of two-zone test and three-zone test. ing.

The initial values TP _HS2 and TP _LS2 of the preheating temperature and the precooling temperature in the case of the two-zone test are: TP _HS2 = (TP _H0 −TP _L0 ) × 3/40 + TP _H0 +5 (° C.) (1) TP _LS2 = (TP _L0 −TP _H0 ) / 15 + TP _L0 −5 (° C)… (2) In addition, the preheating temperature in the case of 3 zone test,
Initial values of precooling temperature TP _HS3 and TP _LS3 are TP _HS3 = (TP _H0 −TP _AT ) / 15 + TP _H0 +5 (° C) (3) TP _LS3 = (TP _L0 −TP _AT ) × 3/40 + TP _L0 − 5 (℃) ········· (4).

However, in the equations (1) to (4), TP _H0 ,
TP _L0 is the high temperature and low temperature exposure temperature, and TP _AT is the ambient temperature (see Fig. 7).

The above initial values may be obtained by calculation, but table data created based on the result of calculation in advance may be stored in the built-in memory of the control unit 32.

Next, the procedure for updating the preheating temperature and the precooling temperature will be described with reference to FIGS. FIG. 4 is a flowchart showing a schematic operation of the device. Setting means 31
High temperature, low temperature exposure temperature TP _H0 , TP _L0 , recovery time t
_{When 1} etc. is set (step S1), (1) to (4)
Based on the formula, the initial values of the preheating and precooling temperatures are obtained (step S2). Then, the first cycle is operated with the initial value of the three-zone test (step S3). This is because even in the two-zone test, the first cycle starts from room temperature.

Next, in the second cycle, the initial value of the two-zone test is used for the two-zone test and three for the three-zone test.
The operation is performed at the initial value of the zone test, and the recovery time t _T at this time is measured (step S4).

Subsequently, it is judged whether or not the preheating temperature and the precooling temperature are determined (step S5). If not determined, the preheating and precooling temperatures are updated from the actual recovery time t _T by the procedure described later ( On the other hand, if determined in step S6), the process directly proceeds to step S7.

Then, after the next cycle, operation is performed at the updated or determined preheating and precooling temperatures (step S
7) Then, returning to step S5, the above operation is repeated.

In the three-zone test, step S4 may be omitted and the recovery time may be measured from step S3. However, in this embodiment, step S4 is provided so that the recovery time is more stable.

Next, the procedure for updating the preheating temperature in step S6 will be described. FIG. 5 is a flowchart showing the procedure for updating the preheating temperature.

First, the overshoot ΔTP when the temperature TP _T of the test tank 3 reaches the high temperature exposure set temperature TP _H0
It is determined whether the _OS (see FIG. 7) exceeds the threshold value TP1 (step S11). If ΔTP _OS > TP1, the overshoot amount is too large. Therefore, whether the control of the high temperature tank heater 11 is the continuous PID control or not. Is determined (step S1
2) If it is not continuous PID control, change to continuous PID control (step S14) and end.

On the other hand, in step S12, the continuous PID
If it is under control, the current preheat temperature TP _HS exceeds the control range and is too high, so the preheat temperature is forcibly reduced by the temperature of the overshoot amount (step S13).

On the other hand, in step S11, ΔTP _OS >
If it is not TP1, it is judged whether or not the actual recovery time t _T is shorter than the set recovery time t ₁ (step S15). If t _T <t ₁ , the preheating temperature TP _HS is too high. , This is lowered by 1 ° C. (step S16).

On the other hand, in step S15, t _T <t ₁
If not, it is determined whether or not the temperature TP _H of the high temperature tank 1 has reached the preheating temperature TP _HS at the start of high temperature exposure (step S17). If not, it means that the heating capacity of the high temperature tank heater 11 is insufficient. The preheating temperature TP _HS at this time is determined, and data such as the high temperature exposure set temperature TP _H0 and the preheating temperature TP _{HS at} this time are stored (step S20).
finish.

On the other hand, in step S17, TP _H ≧ TP
If it is _HS , it is judged whether or not the actual recovery time t _T is equal to or longer than the set recovery time t ₁ +1 (minute) (step S18). If t _T ≧ t ₁ +1 (minute), the preheating temperature is determined. TP _HS
Is increased by 1 ° C./min (3 ° C. if t _T = t ₁ +3 min) (step S19), and the process is completed.

On the other hand, in step S18, t _T ≧ t ₁
If it is not +1 it is assumed that the recovery has been completed within the set recovery time, and the process proceeds to step S20 and ends.

Next, the procedure for updating the precooling temperature in step S6 will be described. FIG. 6 is a flowchart showing the procedure for updating the precooling temperature.

The procedure for updating the precooling temperature is substantially the same as the procedure for updating the preheating temperature shown in FIG. However, step S
33, the temperature of the undershoot amount ΔTP _US (Fig. 7
Increase the pre-cooling temperature TP _{LS (} see only). Further, in step S36, the precooling temperature TP _LS is increased by 1 ° C.

Further, in step S37, it is judged whether or not the temperature TP _L of the low temperature tank 2 has reached the precooling temperature TP _LS at the start of low temperature exposure. If not, the refrigerator 1
Pre-cooling temperature TP at this time due to insufficient cooling capacity of 3
Determined by _LS , and the low temperature exposure set temperature at this time
Store data such as TP _L0 and pre-cooling temperature TP _LS (step S
40) and ends.

In step S39, the precooling temperature is set.
The TP _LS is lowered by, for example, 1 ° C./min (3 ° C. if t _T = t ₁ +3 minutes), and the process ends.

[0054] Thus, when shorter than the set time recovery time t _T of the exposed hot to reduce the preheat temperature TP _{H S,} when longer than the set time so as to raise, set the return time t _T of the exposed low temperature When the time is shorter than the time, the pre-cooling temperature TP _LS is increased, and when the time is longer than the set time, the pre-cooling temperature TP _LS is increased, so that an arbitrary recovery time can be realized, and the data accumulated in the past is not wasted and is compatible. You can get the data.

Further, along with the recovery time t _T , the high temperature exposure set temperature TP _H0 , the preheating temperature TP _HS, and the low temperature exposure set temperature TP _H
Since data such as _L0 and pre-cooling temperature TP _LS is stored, these values can be directly used when performing tests under the same conditions, and the set recovery time can be obtained faster.

The range of temperature change is not limited to 1 ° C. or 1 ° C./minute, and an appropriate temperature range may be selected.

[0057]

As described above, according to the present invention, when the arrival time from the start of exposure to the temperature of the test tank reaching the preset temperature is shorter than the set time, the preparation temperature is preset. On the other hand, when the set temperature is longer than the set time, the preparation temperature is separated from the preset temperature, so that the arrival time can be set to an arbitrary value.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control configuration of a thermal shock device as an example of an environment test device to which the present invention is applied.

FIG. 2 is a schematic configuration diagram of a thermal shock device as an example of an environmental test device to which the present invention is applied.

3A and 3B are schematic configuration diagrams of a thermal shock device showing states of respective dampers and a circulation direction of air in the device. FIG. 3A shows a high temperature exposure mode state, and FIG. 3B shows a low temperature exposure mode state.

FIG. 4 is a flowchart showing a schematic operation of the apparatus.

FIG. 5 is a flowchart showing a procedure for updating a preheating temperature.

FIG. 6 is a flowchart showing a procedure for updating a precooling temperature.

FIG. 7 is a diagram showing a general temperature transition in a thermal shock test.

[Explanation of symbols]

 1 high temperature tank (preparation tank) 2 low temperature tank (preparation tank) 3 test tank 5 sample 6a high temperature tank partition 6b high temperature inlet 6c high temperature outlet 6d low temperature inlet 6e low temperature outlet 6f outside air outlet 6g outside air inlet 11 High Temperature Tank Heater 12a to 12c Fan 13 Refrigerator 14 Low Temperature Tank Heater 16a to 16f Damper 21 High Temperature Tank Temperature Sensor (Preparation Tank Temperature Detection Means) 22 Low Temperature Tank Temperature Sensor (Preparation Tank Temperature Detection Means) 23 Test Tank Upwind Temperature Sensor (Test tank temperature detecting means) 24 Test tank lee temperature sensor (test tank temperature detecting means) 25 Ambient temperature sensor 31 Setting means 32 Control section 33 Sequence controller 321 and 322 selecting means 323 Timing means 324 Comparison means 325 Temperature changing means

Claims (1)

[Claims] 1. A preparation tank and a test tank having different preparation temperatures are provided, the preparation tank and the test tank are communicated with each other, and the sample placed in the test tank is exposed to an atmosphere of a preset temperature. In an environmental testing device that applies temperature change stress, a preparation tank temperature detection means provided in the preparation tank,
Test tank temperature detecting means provided in the test tank, setting means for setting the arrival time from the start of exposure until the temperature of the test tank reaches the preset temperature, and measuring the arrival time And a comparing means for comparing the timed arrival time and the set time, and when the timed arrival time is shorter than the set time, the preparatory temperature of the preparatory tank is the preset temperature. And a temperature changing means for separating the preparation temperature of the preparation tank from the preset temperature when the timed arrival time is longer than the preset time. Time control device.