JP3356019B2 - Temperature control device for thermostat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a large number of IC devices on a test board, carrying the IC devices into a temperature-controlled thermostat, and heating the IC devices to a predetermined temperature in the thermostat. The present invention relates to a temperature control device for a thermostat, which is provided in a test device for testing electrical characteristics by connecting the test head to a test head in a cooled state.

[0002]

2. Description of the Related Art An IC device (integrated circuit element, hereinafter simply referred to as a device) is subjected to a test for electrical characteristics after its manufacture. As a device for testing the electrical characteristics of a device, a test head for energizing the device is used. , A handler including a loader unit and an unloader unit, and a device transfer mechanism. The device test is performed not only when the device is tested at normal temperature but also when the device is heated (high temperature test) and when the device is cooled (low temperature test). These high-temperature tests and low-temperature tests are performed under strict temperature control in order to test all devices under the same temperature conditions. A constant temperature bath is used to control the temperature of the device.The device is kept in a constant temperature bath maintained at a constant temperature condition for a predetermined time, and the device is heated to a set temperature or cooled. And connect it to the test head.

[0003] In order to strictly control the temperature in the thermostat,
The constant temperature bath is provided with one or both of a temperature adjusting unit including a heating unit and a cooling unit, and a temperature sensor for detecting a temperature in the constant temperature bath is provided. And always monitor the temperature inside the thermostat with the temperature sensor,
When the temperature in the thermostat changes, the temperature in the thermostat is stabilized by operating the temperature adjusting means. As the temperature control means for this purpose, the temperature control means is normally operated based on the deviation between the target temperature and the temperature detected by the temperature sensor, using the temperature in the thermostat as a feedback system. This control is generally performed by a PID operation in which a proportional operation, an integration operation, and a differential operation are combined from the viewpoint of control accuracy, responsiveness, and the like.

[0004] Since the thermostatic bath is formed by a heat insulating wall and has excellent heat insulating properties with respect to the outside air, the temperature changes slowly even if the temperature is once reached to the set temperature and left as it is. . In performing the temperature control means in the PID operation, when the temperature change per unit time is small,
If the proportional gain and the integration time and the differentiation time are set to match, the error range can be minimized. For example, if the target temperature in the thermostat is set to 110 ° C. in performing the high temperature test, the error range can be suppressed to within ± 1 ° C. depending on the combination of the above-described parameters. However,
The reason why such fine temperature control can be performed is that the change in the temperature inside the bath is small, and if a rapid temperature change occurs, it takes a long time to return the inside of the bath to the set temperature. And the response becomes poor. in short,
In controlling the temperature inside the bath by the temperature control means, if the control is to be performed with high accuracy, the response speed to changes in the bath temperature will be slow, and if the response speed is increased, the control accuracy will be reduced accordingly. Will do. Therefore, in order to improve the control accuracy, it is necessary to reduce the change in the temperature inside the chamber during the test, and for this purpose, regardless of the change due to the temperature difference between the inside and outside of the chamber, Changes in temperature must be minimized.

In order to perform a test efficiently, a large number of devices are mounted on a test board, and a large number of devices are tested at the same time. Therefore, the test board is a dedicated jig for testing the electrical characteristics of the device, and the test board is carried into the thermostat.
The device is usually stored in a tray at the time of storage, transportation, or the like to ensure its convenience. Therefore, as a handler, a loading operation of taking out the device from the tray and mounting it on the test board is performed in the loader unit, and an unloading operation of transferring the device from the test board to the tray is performed in the unloader unit. The unloading work is classified and stored in trays based on the test results. However, it can be divided into non-defective products, defective products, and three types of non-defective products, defective products, and re-inspected products. Separate and store in a tray. In the case where the storage unit of each device in the tray and the test result of the device stored therein are stored, the trays do not need to be classified. In the loader section, trays accommodating devices to be tested are stacked and arranged, and devices are sequentially transferred from the uppermost tray. In the unloader section, empty trays are stacked, and when the tray is full, the tray is discharged and the next empty tray is placed at a position where the device can be stored.

In the loader section, devices are transferred from the tray to the test board, and in the unloader section, devices are transferred from the test board to the tray. However, since these loader section and unloader section are installed outside the thermostat, The test board will be carried in and out of the thermostat. Therefore,
When the test board is carried into the thermostat from outside, if there is a difference between the temperature of this test board and the temperature in the chamber,
The temperature in the bath changes. In particular, when as many test devices as possible are mounted on the test board in order to perform the test efficiently, the test board becomes large in size, and the heat capacity increases accordingly. Therefore, the temperature of the test board becomes a disturbance factor that changes the temperature in the bath. In consideration of the above points, the transport mechanism of the handler is configured to reciprocate the test board into and out of the thermostat, and by reducing the time that the test board stays outside the thermostat, the temperature of the test board is reduced. The temperature of the test board heated (or cooled) to substantially the same temperature as the set temperature of the device in the chamber can be suppressed from changing, thereby minimizing temperature changes due to disturbance in the constant temperature chamber. Can be suppressed.

[0007]

The time that the test board stays outside the thermostat is not always constant. When a failure or trouble occurs in the IC tester or the handler, some test boards must be kept outside the thermostat for a predetermined time. Such troubles and troubles include serious troubles such as the entire test apparatus having to be stopped for a long time, and mild troubles such as the handling means dropping the device when transferring the device. For some troubles, the handler can be stopped for several minutes or put into a standby state, and can be repaired.

[0008] Even when the test apparatus is operating normally,
The residence time of the test board outside the thermostat may change. That is, the tray may need to be replaced during the loading and unloading operations of the device. Therefore, the residence time of the test board outside the thermostat varies depending on whether the tray needs to be replaced during the loading operation and the unloading operation and when it is not necessary. In addition, if it is necessary to exchange trays during both the unloading operation and the loading operation, the test board must stay outside the thermostat for a longer time. Further, when all the trays have been paid out by the loader section or the unloader section, it is necessary to replenish the trays, and in this case, the test board needs to wait outside the thermostat for a longer time.

As described above, if the test board is placed outside the thermostat for a long time and then carried into the thermostat, it becomes a disturbance factor that greatly changes the temperature in the chamber. The temperature control in the chamber by the above-described PID control or the like is a control based on the assumption that the temperature change in the thermostatic chamber is minute, and when a test board that has been staying outside the thermostatic chamber for a long time is carried in, disturbance is caused. If the same temperature control is performed even when the temperature in the constant temperature bath changes greatly due to a factor, there is a problem that it takes a long time to return to the set temperature range.

The present invention has been made in view of the above points, and an object of the present invention is to provide a test board in which the temperature inside a constant temperature bath is greatly changed by the residence time of the test board outside the bath.
An object of the present invention is to enable control so as to quickly fall within a set temperature range.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a test board on which a large number of IC devices are mounted for a predetermined period of time, and the electrical characteristics of the IC devices are set at a set temperature. In order to perform a test, a thermostat provided with at least one temperature adjusting means of a heating means and a cooling means is provided, and the test board is reciprocated inside and outside the thermostat, and the thermostat is provided. A temperature sensor is provided in the controller, a detection signal of the temperature sensor is taken into the control unit, and the temperature adjustment unit is operated.
The temperature control is performed so as to maintain the inside of the thermostat at a predetermined set temperature, and the control unit performs the control in a normal temperature control mode according to a residence time of the test board outside the thermostat. It is characterized in that it is configured to be switchable between temperature control and temperature control performed in a temperature control mode at the time of occurrence of disturbance for recovering the temperature in the constant temperature bath.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 1 shows the overall configuration of a test apparatus for testing the electrical characteristics of a device. In the figure, 1 is a loader section, 2 is a test section, 3 is an unloader section, and the loader section 1 is provided with a trace stocker 1a and an empty tray collecting section 1b. The test section 2 faces a test head 4 of an IC tester, and the unloader section 3 is provided with an empty tray supply section 3a, a good device storage section 3b, and a defective device storage section 3c.

The loader unit 1 and the unloader unit 3 have the configuration shown in FIG.
Are arranged in a stacked state. The tray 5 is formed of a plate-shaped member, and has a large number of device housing portions 5a formed in a matrix, and the device D is housed in each of the device housing portions 5a. The tray 5 is used for storing and transporting the devices D, and is designed to accommodate as many devices D as possible.

From the loader unit 1 to the test unit 2 and the test unit 2
The test board 6 is used to carry the device D into the unloader unit 3 from the server. Since the test board 6 is connected to the test head 4 in a state in which the device D is accommodated, the device D can be positioned accurately. To this end, as shown in FIGS. 3 and 4, the test board 6 has a
a is provided in a required number. The device mounting part 6a is provided with a pair of a fixed positioning wall 7 and a pair of device clamps 9 urged in a clamped state by a spring 8. When the device D is mounted, the positioning wall 7 Accurately positioned and device clamp 9
And is stably held.

In the loader section 1, the device D is transferred from the tray 5 to the test board 6, and in the unloader section 3, the device D is transferred from the test board 6 to the tray 5.
Since no special positioning means or fixing means is provided in the device housing part 5a of the tray 5, the package part P of the device D is easily taken out or housed by sucking the package part P with the vacuum suction head of the robot. be able to. On the other hand, the test board 6
Therefore, it is necessary to release the clamp by the device clamp 9 in order to mount or take out the device D. For this reason, as shown in FIG. 4, in the loader unit 1 and the unloader unit 3, the robot 10 as the transfer means of the device D is provided with a pair of means as the release means of the device clamp 10 in addition to the vacuum suction head 10a. Is mounted. Thus, when the robot 10 is lowered, first, the device clamp 9 is pushed by the push rod 10b to release the clamp of the device D, and then the device D can be clamped by the vacuum suction head 10a. .

In this test apparatus, the electrical characteristics of the device D are tested under a predetermined temperature condition. For this purpose, the test section 2 is provided with a thermostat 11. Then, as shown in FIG. 5, after the device D is brought into a constant temperature state in the thermostat 11,
The electrical characteristics of the device D are tested by bringing the leads L into contact with the contact pins 4a of the test head 4. The devices D are not individually connected to the test head 4 but are mounted on the test board 6 and all the devices D are tested at the same time.

For example, in the case of a high temperature test for testing the device D under a high temperature condition such as 110 ° C.,
The temperature inside the thermostat 11 is controlled so as to reach this set temperature. The surrounding wall is formed of a heat insulating wall to block the inside of the thermostat 11 from the outside air. In order to control the temperature in the thermostat 11, the internal structure of the thermostat 11 has, for example, the configuration shown in FIG. That is, as shown in the figure, a heater 12 as a temperature adjusting means is provided in the thermostat 11, and a circulating fan 13 is provided to circulate the heat of the heater 12 into the thermostat 11. And a duct 14 are provided. The duct 14 is provided with an air inlet 14a and a plurality of outlets 14b, and the duct 14 circulates internal air so that heat is distributed throughout the thermostat 11.

The above configuration is for performing a high-temperature test, and for performing a low-temperature test, the cooling means for supplying a coolant such as liquid nitrogen instead of the heater 12 as the heating means is used as the temperature adjusting means. When a high-temperature test and a low-temperature test are performed, both a heater and a cooling unit are provided. In some cases, in both the high-temperature test and the low-temperature test, in order to more strictly control the temperature in the chamber, both the heater and the cooling means are operated. In the following description, it is assumed that the temperature inside the thermostat 11 is adjusted only by the heater 12 in the high temperature test. However, the temperature control device of the present invention can be applied to the low temperature test, and the temperature adjustment can be performed. It is also possible to use a heater and a cooling means.

In the thermostat 11, a plurality of test boards 6 are provided.
Are arranged so as to be lined up and down. Of the plurality of test boards 6, the portions where the test boards of each stage except the uppermost test board are located are the preheat positions, and the uppermost stage is the test position. As is clear from FIGS. 1 and 6, the constant temperature bath 11 is provided with a shutter 15a for carrying in at the lowermost stage of the preheating position, and a shutter 15b for carrying out between the preheating position and the test position. Is provided. Accordingly, the test board 6 opens the shutter 15a on the lower side of the thermostat 11, and is carried into the thermostat 11, while the device D mounted on the test board 6 is fed while being pitch-fed upward. It is heated to the set temperature at which the test is performed. And
When it reaches the uppermost stage, it is connected to the test head 4 and a test of the electrical characteristics is performed. After the test, the upper shutter 15b is opened and the test piece is carried out of the thermostat 11.

The internal temperature of the thermostat 11 is always maintained at a set temperature. For this purpose, a temperature sensor 16 for detecting the temperature in the thermostat 11 is provided. Then, the temperature in the thermostatic chamber 11 is constantly detected by the temperature sensor 16, and when the temperature decreases, the heater 12 is operated to increase the temperature to the set temperature. For this purpose, as shown in FIG. 7, a temperature control means 17 is provided. The temperature control means 17 is composed of, for example, a microcomputer or the like. 16 is compared with a preset target temperature, and if there is a deviation in the detected temperature, the heater 12
Is controlled to adjust the temperature in the bath to the target temperature. Here, this temperature control is performed by PID control in which each parameter of the proportional operation, the integral operation, and the differential operation is set to a predetermined value in consideration of the fineness and responsiveness of the control. The control operation signal and the adjustment signal are generated based on the difference between the in-chamber temperature and the target temperature detected at 16, and the operation of the heater 12 is controlled. In this way, fine temperature control is performed such that an error in the constant temperature chamber 11 with respect to the target temperature is suppressed within ± 1 ° C.

The thermostatic chamber 11 has good heat insulating properties, and the temperature in the chamber changes slowly unless there is a special disturbance factor. The disturbance factor that changes the temperature in the bath is when the test board 6 is taken in and out, and particularly when the temperature of the test board 6 is lowered, when the test board 6 is carried into the constant temperature bath 11, the temperature in the bath is reduced. descend. Moreover, in order to increase the number of devices D mounted on the test board 6 in order to increase the efficiency of the test, it is necessary to increase the size of the test board 6, increase the heat capacity, and increase the temperature of the entire thermostat chamber 11. When the internal volume of the thermostatic chamber 11 is reduced in order to achieve uniformity and enable energy-saving operation, the temperature in the thermostatic chamber 11 is reduced based on the difference between the temperature of the test board 6 and the temperature in the thermostatic chamber 11. Temperature greatly changes. However, as described above, in order to secure the fineness of the temperature control in the thermostat 11, it is necessary to reduce the temperature change per unit time during the temperature control. Then, when the temperature in the chamber changes rapidly due to a disturbance factor or the like, it takes a long time to recover to the set temperature, and if the test is continued as it is, the temperature of the device D at the time of the test varies. Would.

The test board 6 takes a closed loop such that the test board 6 moves from the loader section 1 to the unloader section 3 via the test section 2 and returns to the loader section 1 again. In addition, the test board 6 is heated to the set temperature together with the device D in the thermostat 11. Therefore, if the unloading operation performed by unloading the test board 6 from the thermostatic chamber 11 to the unloader unit 3 and the loading operation performed by the loader unit 1 are performed quickly, a decrease in the temperature of the test board 6 during the period is minimized. Then, when it is carried into the constant temperature bath 11 again, the temperature in the bath does not decrease so much.

At least one of the test boards 6 reciprocating inside and outside the thermostat 11 is located outside the thermostat 11. If a failure occurs in any of the devices and the entire test device stops completely, a restart operation will be performed. However, there may be a trouble that does not completely stop the test apparatus, and in this case, the handler is in a standby state. Although no trouble occurs, all the trays 5 are completely discharged from the trace stocker 1a in the loader unit 1, the empty tray collection unit 1b becomes full with empty trays 5, or the unloader unit 3 When the empty tray 5 is completely dispensed by the empty tray supply section 3a or the like, operations such as tray replenishment must be performed. In this case, the handler is also in a standby state. Even if the handler temporarily enters the standby state, the restart operation is not performed at the time of restart, but the subsequent operation is continued. In the standby state, the thermostat 1
The test board 6 located outside of 1 will stay at the same position.

In a standby state or the like, the time during which the test board 6 stays outside the thermostatic chamber 11 varies greatly, and may be a very short standby time, for example, several seconds, or several minutes or more. In some cases, the system is in a standby state for a long time. If the test board 6 stays outside the thermostat 11 for a long time, the temperature of the test board 6 will be significantly lowered. When the test board 6 is carried into the thermostatic chamber 11, the temperature in the chamber is extremely lowered. In this state, if the temperature is controlled by the PID operation for performing normal fine control by the temperature control means 17, it takes a considerably long time to recover to the set temperature.

Then, the residence time of the test board 6 outside the thermostat 11 is detected, and when the time of the test board 6 outside the chamber becomes longer than the set time, the normal temperature control mode is set. The temperature control means 17 controls the operation of the heater 12 in a different temperature control mode at the time of occurrence of disturbance to perform temperature control, and the temperature control means 17 has two temperature controls so that the temperature in the thermostatic chamber 11 can be quickly restored to a set value. Control mode is set. The normal temperature control mode is temperature management on the assumption that there is no disturbance factor that greatly disturbs the temperature in the thermostat 11. Thus, if there are no disturbance factors,
Since the temperature change in the thermostatic chamber 11 is extremely slow, a more precise temperature control is performed by reducing the gain per unit time, and the error is suppressed to ± 1 ° C. or less. On the other hand, in the case of the temperature control mode due to a disturbance factor, since the temperature in the thermostat 11 greatly changes,
To quickly recover to or near the set temperature,
Increase the gain per unit time. However, in this temperature control mode at the time of occurrence of disturbance, fine control of the temperature cannot be performed as in the normal temperature control mode. Therefore, in the normal temperature management and the temperature management when a disturbance occurs, control is performed by changing each parameter of the proportional gain, the integration time, and the differentiation time by the PID operation. These parameters are appropriately set based on the set temperature of the thermostat 11 and its volume, the material and size of the test board 6, and the like. Here, since the differentiation operation has a significant effect on the control speed, it is necessary to change at least the differentiation time between the normal temperature control mode and the temperature control mode when disturbance occurs.

Whether or not the test board 6 has stayed outside the chamber to such an extent that the temperature in the thermostatic chamber 11 changes can be detected by the operation of the operating mechanism of the handler. For example, when the handler enters a standby state, its driving mechanism stops. By measuring the stop time, the temperature control unit 1 of the test board 6
1 can detect the residence time outside. In particular, test board 6
In order to convey the inside and outside of the constant temperature bath 11, a conveying means such as a conveyor is provided, and this conveying means operates intermittently.
If the stop time is measured, the temperature of the thermostat 1
1 and the residence time outside can be detected.

The test board 6 in the thermostat 11
It is also possible to detect the time that the test board 6 stays outside the tank based on the operation of the shutters 15a and 15b that control the loading and unloading of the test board. That is, when the test board 6 is carried into the thermostat 11, the shutter 15a opens, and upon completion of the carrying, the shutter 15a closes immediately. After the test of the device D mounted on the test board 6 is completed, the shutter 15b is opened, the test board 6 is carried out, and then the shutter 15b is closed. As for the timing for loading and unloading the test board 6, the test board 6 after the test is first unloaded, and each test board 6 at the preheating position is sent one pitch upward, and then a new device D is mounted. The loaded test board 6 is carried in. Therefore, the shutter 15b
Is opened, the test board 6 is carried out of the thermostat 11, and after the shutter 15b is opened again, the shutter 15a is opened.
It is carried in. Therefore, a counter for measuring time is provided, and starts counting when the shutter 15b is opened, and ends counting when the shutter 15a is opened for the second time. Is measured. However, since the shutter 15b is opened again while the time is being measured by the counter, two counters must be provided so that counting is started each time the shutter 15b is opened.

The time that the test board 6 stays outside the tank is measured based on the operation state of the handler or the opening and closing operation of the shutters 15a and 15b, and is set in the temperature control means 17 in advance. This is compared with the time (for example, about 2 to 5 minutes). If the measurement result is equal to or shorter than the set time, the temperature control unit 17 performs temperature control in a normal temperature control mode. If the set time is exceeded, the mode is switched to the temperature control mode at the time of occurrence of disturbance, the temperature in the bath is quickly raised to the set temperature range, and then the state is returned to the normal temperature control mode. Therefore, a method of executing the temperature management in the thermostat 11 will be described based on the flowchart of FIG.

First, when the apparatus is started (including a restart operation), the temperature in the thermostatic chamber 11 must be quickly raised to the set temperature. When the apparatus is started, the temperature sensor 16 is also operated, and the temperature in the bath is always detected. Therefore, the temperature sensor 1 is compared with the set temperature.
It is detected whether or not the temperature in the bath according to 6 has reached the set temperature (step 1). If the temperature in the bath is equal to or lower than the set temperature, the heater 12 is continuously operated to raise the temperature in the bath to the set temperature (step 2).

When the temperature in the thermostat 11 reaches the set temperature,
The temperature in the thermostat 11 is controlled in the normal temperature control mode (step 3). In this state, the test board 6 is transported, and the test of the electrical characteristics of the device D mounted on the test board 6 is started (step 4). When the test is started, the thermostat 1 of the test board 6
The residence time outside the area 1 is detected (step 5). Specifically, this time detection can be performed by measuring the stop time of the transport means of the test board 6, measuring the open / close time of the shutters 15a and 15b, and the like.

If the residence time of the test board 6 outside the thermostat 11 is within the set time, the process returns to step 3 to continue the temperature control in the normal temperature control mode. When it is detected that the set time has been exceeded, the temperature chamber 1 of the test board 6 is detected.
The temperature in the thermostat 11 will be rapidly lowered by carrying it in. Therefore, the test board 6 outside the chamber is carried into the thermostatic chamber 11 (step 6), and immediately after that, the mode shifts to the temperature control mode at the time of occurrence of disturbance and the test board 6
Is stopped (step 7). As a result, the test of the device D is temporarily interrupted, and this state is continued until the temperature in the bath returns to the set temperature (step 8). When the temperature in the bath recovers to the set temperature, the process returns to step 3 to perform the temperature control in the normal temperature control mode, and the test of the device D is restarted.
Here, when performing the temperature recovery in the temperature control mode when the disturbance occurs, one test board 6 is newly added to the thermostat 1.
It is carried out from 1 and stays outside the tank. However, since the temperature in the thermostatic chamber 11 is quickly recovered, the temperature of the test board 8 newly carried in the thermostatic chamber 11 is increased again unless the temperature drops remarkably due to staying outside the chamber for an extremely long time. There is almost no possibility that the residence time of the test board 6 carried out of the tank 11 outside the tank exceeds the set time. Even if the set time is exceeded, when the test board 6 is re-loaded into the thermostatic chamber 11, the mode is again shifted to the temperature control mode at the time of the occurrence of disturbance, and the temperature is quickly recovered. Therefore, if the temperature control in the temperature control mode at the time of the occurrence of the disturbance of 2 degrees at the maximum is performed, the temperature in the thermostat 11 can be completely recovered.

As described above, the occurrence of disturbance causes the constant temperature chamber 11
When the temperature inside the chamber suddenly changes, the temperature inside the constant temperature chamber 11 can be accurately controlled by detecting the sudden change and quickly recovering the temperature inside the chamber. The characteristics can be tested, the test accuracy can be improved, and the need for re-testing due to test temperature variations is eliminated. In addition, when the temperature in the bath is unavoidably changed, the time until the temperature can be recovered can be shortened, and the interruption time of the test can be minimized.
Efficient operation of the device is ensured.

[0033]

As described above, according to the present invention, when the temperature inside the constant temperature chamber is greatly changed due to the occurrence of the disturbance while the temperature inside the constant temperature chamber is controlled in the normal temperature control mode, the disturbance is generated. The temperature control mode can be switched to the temperature control mode, so that the temperature inside the constant temperature chamber can be controlled very strictly, and the temperature inside the chamber can be quickly restored to the set temperature when a disturbance occurs. To play.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a test device for electrical characteristics of an IC device to which a temperature control device of the present invention is applied.

FIG. 2 is an external view showing a tray and a device.

FIG. 3 is a configuration diagram of a main part of a test board.

FIG. 4 is a cross-sectional view of the test board shown together with device transfer means.

FIG. 5 is an explanatory diagram showing a state where a device is connected to a test head by a test board.

FIG. 6 is a configuration explanatory view showing an internal configuration of a thermostat.

FIG. 7 is an explanatory diagram of a configuration of a temperature control mechanism in a thermostat.

FIG. 8 is a flowchart illustrating a procedure for controlling the temperature of a thermostat.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Loader part 2 Test part 3 Unloader part 4 Test head 5 Tray 6 Test board 11 Constant temperature bath 12 Heater 16 Temperature sensor 17 Temperature control means

Continuation of the front page (56) References JP-A-6-66880 (JP, A) JP-A-61-144580 (JP, A) JP-A-7-270490 (JP, A) (58) Fields studied (Int .Cl. ⁷ , DB name) G01R 31/26 G01R 31/28-31/3193 H01L 21/66

Claims (1)

(57) [Claims] At least one of a heating means and a cooling means for allowing a test board on which a large number of IC devices are mounted to stay for a predetermined period of time and testing the electrical characteristics of the IC device at a set temperature. A temperature chamber provided with a temperature adjusting means for reciprocating the test board in and out of the temperature chamber; and a temperature sensor provided in the temperature chamber to control a detection signal of the temperature sensor. And operating the temperature adjusting means to perform temperature control so as to maintain the inside of the thermostat at a predetermined set temperature, wherein the control means includes a residence time of the test board outside the thermostat. The temperature control can be switched between a temperature control performed in a normal temperature control mode and a temperature control performed in a temperature control mode in the event of a disturbance for recovering the temperature in the constant temperature bath. A temperature control device for a thermostat.