JPH11142469A - Method and device for measuring low and high temperature electric characteristics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately adjust a temperature for elements to be measured and suppress a supply power to a Peltier (thermoelement) in measuring the electric characteristics of the elements to be measured of a semiconductor device at low and high temperatures. SOLUTION: The temperature of a cold plate 3 heat-transferred from a thermoelement, Peltier 22, is controlled, heat is transferred to the element to be measured 2, the temperature is controlled at a low or high temperature, and the electric characteristics are measured. Also an air curtain is formed with dry air 8 to shield from air outside a tank and air convection is maintained under windless condition so as to prevent dew condensation from occurring inside the tank especially when the temperature is set at a low temperature. Thus heat loss is suppressed to reduce the supply power to the Peltier 2, and a variation in temperature of the elements to be measured 2 is suppressed to increase the accuracy of temperature control. Then the temperature of air inside the tank around the elements to be measured 2 and the temperature of the cold plate 3 are detected to calculate the predicted temperature of the element to be measured 2 and control the temperature of the Peltier 22 so that it is coincident with a set temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the electrical characteristics of a device to be measured in a semiconductor device or the like from a low temperature to a high temperature.

[0002]

2. Description of the Related Art In product inspection of semiconductor devices,
It is important to measure electrical properties with respect to temperature. 2. Description of the Related Art When measuring a device under test such as a semiconductor device at a low or high temperature, a device that performs temperature control using the Peltier effect of a thermoelectric device, adjusts the temperature of the device under test, and measures electrical characteristics is well known. .

Japanese Patent Application No. 59-189331 (Japanese Patent Application Laid-Open No. 61-68568), Japanese Patent Application Laid-Open No. 1-286322, and Japanese Patent Application Laid-Open No. 4-10
No. 4072 and JP-A-4-144248.

[0004] Among them, Japanese Patent Application Laid-Open No. 61-68568 discloses an electronic device in which an IC to be measured is set in the vicinity of a cooling part in which a Peltier thermoelectric element is embedded, and dew condensation during cooling is prevented by an air curtain. A low and high temperature handler device with a cooler is described.

This will be schematically described with reference to FIGS. I
The measured IC 104 is stored in the C supply magazine 111,
In this case, while moving in the direction of arrow C in FIG.
08 sequentially.

A Peltier device 105 is embedded in the cooling section 103, and the IC under test 104 is cooled and heated by the cooling effect of the Peltier element 105. At that time, the temperature sensor 106 detects the temperature of the cooling section 103. The water cooling mechanism 107 absorbs heat generated when the Peltier element 105 cools down. The measured IC 104 is the guide rail 1
The temperature reaches the target temperature while passing through the preliminary cooling / heating unit 101 via 08, and is maintained at a desired temperature while being measured by the measuring unit 102.

The temperature detected by the temperature sensor 106 is compared with a set temperature, and a Peltier element 105 is
Control the temperature of the

In addition, air at a constant pressure is supplied to the air jet port 109, and the periphery of the cooling / heating section 103 is shut off by an air curtain. Thereby, by eliminating the temperature difference between the cooling / heating section 103 and the surrounding area, the condensation of the cooling / heating section 103 is prevented, and the insulation failure of the Peltier element 105 embedded in the cooling / heating section 103 is prevented.

[0009]

However, the apparatus described in the publications shown in FIGS. 4 to 6 has the following problems to be solved.

The first problem is that the device under test IC1
04 is that the accuracy of temperature adjustment is low.

The reason is that a large convection of air is generated by the air curtain. Therefore, heat loss increases due to convection of air generated around the IC and the Peltier, and heat fluctuation of the IC increases. Another reason is that the temperature of the air is not used for control because there is only one cooling part for adjusting the temperature of the IC.

One of the causes of the large convection of air is as follows.
6 is that the distance between the IC and the air curtain is short. That makes it difficult to balance the air curtain. Furthermore, the viscosity of the air curtain blown from the surroundings pushes the air near the IC to the outside, causing the pressure to drop and causing turbulence.

The second problem is that the power supplied to Peltier is large. In other words, a large convection is generated by the air curtain, so that a large heat loss is generated, and the power supply is increased.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method and an apparatus for measuring low- and high-temperature electrical characteristics, which enable high-precision temperature adjustment of a device to be measured in a semiconductor device or the like and suppress the power supplied to a Peltier. I will provide a.

[0015]

According to the method for measuring low- and high-temperature electrical characteristics of the present invention, a device to be measured is carried in and out of a measuring tank via a storage tray, and a cold plate is transferred from the thermoelectric device utilizing the Peltier effect. By controlling the temperature of the cold plate and transferring the heat of the cold plate to the device under test via the receiving tray, the temperature of the device under test is adjusted at a low or high temperature to measure the electrical characteristics. After the setting, the temperature of the air in the chamber around the element to be measured and the temperature of the cooling plate are detected, and the predicted temperature of the element to be measured is calculated based on the air temperature in the chamber and the temperature of the cooling plate. So that the temperature matches the preset temperature
The temperature of the thermoelectric element is controlled.

In this case, a correlation between the air temperature in the tank, the cold plate temperature and the set temperature is tabulated,
With reference to the table, the cold plate temperature can be obtained for the set temperature and the air temperature in the tank, and
The correlation between the cold plate temperature and the temperature of the thermoelectric element is tabulated, and the thermoelectric element temperature can be determined for the calculated cold plate temperature.

Further, an air curtain is formed to shield air from the outside of the tank so that air convection is maintained in a windless state.
In particular, when a low temperature is set, the penetration of moisture from the outside of the tank is blocked by an air curtain to prevent dew condensation inside the tank. By maintaining air convection around the device under test in a windless state, it is possible to suppress heat loss, reduce power supplied to the thermoelectric device, suppress temperature fluctuations of the device under test, and increase temperature adjustment accuracy. it can.

On the other hand, the low- and high-temperature electrical characteristic measuring apparatus according to the present invention controls the temperature of the cooling panel which is carried in and out of the measuring tank via the receiving tray and which is transferred from the thermoelectric element utilizing the Peltier effect. Then, by transferring the heat of the cold plate to the element to be measured via the storage tray,
A device for measuring electrical characteristics by adjusting the temperature of a device under test at a low or high temperature, and detecting an air temperature in a bath around the device to be measured and a temperature of the cold plate. A cold plate temperature sensor to be detected, an element temperature calculating section for calculating a predicted temperature of the device under test based on each detection signal of the air temperature in the bath and a cold plate temperature, and a predicted temperature of the device under test is preset. An element temperature command section to perform, a predicted temperature calculation value signal output from the element temperature calculation section, and a predicted temperature setting signal output from the element temperature command section, and the predicted temperature matches the set temperature. And a temperature controller for sending a command signal to the thermoelectric element to adjust the temperature.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a method and apparatus for measuring low- and high-temperature electrical characteristics according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention. In the measuring tank 5, an element 2 to be measured, for example, a semiconductor device or the like whose electric characteristics are to be measured is arranged on the transfer tray 1.

In the measuring tank 5, a Peltier 22 is arranged as a thermoelectric element used for adjusting the temperature of the device under test 2. The cooling / heating plate 3 having a high heat transfer effect from the Peltier 22 is provided.
Are arranged below the tray 1 at a predetermined position in the tank.

A temperature sensor 9 for measuring the temperature of the cold plate 3 and a temperature sensor 10 for measuring the temperature of the air around the element 2 are provided. A probe (contact terminal) 12 and a tray carrying-in port 6 and a tray carrying-out port 7 for carrying the tray 1 in and out are provided.

Further, at the tray loading / unloading ports 6 and 7, dry air emitting sections 15 are arranged, respectively. Here, the dry air 8 is blown out toward the outside in order to prevent external moisture from entering the inside of the measuring tank 5 and forming dew when the low temperature is set.

In the vicinity of the tray loading / unloading ports 6 and 7,
A dry air supply unit 16 for supplying dry air for adjusting the tank internal pressure is provided. Here, the inside of the tank is prevented from leaking to the outside of the tank due to the viscosity of the dry air 8 to prevent the internal pressure from lowering, and the dry air 8 is supplied to keep the vicinity of the element 2 in a windless state.

The dry air generating section 17 is provided with the dry air emitting section 1.
5 and the dry air to the dry air supply unit 16 are supplied from a dry air generation unit 17.

A transport rail 18 is provided extending in the front-rear direction of the measuring tank 5, that is, in the carry-in / out direction, so that the tray 1 is carried from the carry-in port 6 to the carry-out port 7.

On the other hand, as an element temperature control system, there are provided a temperature control section 4, an element temperature command section 20, an element temperature calculation section 11, and the like. The temperature control unit 4 matches the temperature of the element 2 with the command temperature based on the output signal from the element temperature command unit 20 for setting the element temperature and the output signal from the element temperature calculation unit 11 for calculating the current element temperature. Thus, the temperature adjustment control of the Peltier 3 is performed.

Driving unit 1 for driving tray transport rail 18
In step 9, using the signals from the measurement start signal generator 21 and the measurement probe driver 14, the tray 1 is transported and the element 2 is positioned at the measurement position. The measurement probe drive unit 14 drives the measurement probe 12 using signals from the tray transport rail drive unit 19 and the measuring device 13 to perform positioning to a transportable position and positioning to a measurement position. Measuring instrument 13
Can measure the electrical characteristics of the element 2 using signals obtained from the probe driving unit 14 and the measurement probe 12.

The operation of the first embodiment having the above configuration will be described below.

Temperature detection signals from the temperature sensors 9 and 10 for the cold plate and the air are sent to the element temperature calculator 11. The element temperature calculator 11 calculates the predicted temperature of the device under test 2 based on the temperature detection signal, and outputs an element temperature signal of the calculated value. The calculation of the predicted temperature of the device under test 2 is performed by tabulating the relationship between the preset cooling plate temperature and the air temperature around the device.

FIG. 2 is a graph showing a correlation table between the ambient temperature of the device under test 2 and the temperature of the cooling plate 3 when the device temperature is constant. In the graph, for example, when the temperature of the cooling / heating plate 3 is a ° C. and the air temperature is b ° C., the current temperature of the device under test 2 can be obtained as 20 ° C.

The temperature control section 4 is provided with an element temperature command section 2.
0, which is connected to the element temperature calculation unit 11, controls the temperature of the Peltier 22 based on the element temperature command value signal and the predicted element temperature signal, and adjusts the temperature of the device under test 2 to match the command temperature. The control method includes, for example, general-purpose PID control. For example, assuming that the element temperature command value is 25 ° C., in the correlation table of FIG. 2, for example, if the air temperature is temporarily set to b ° C., it can be determined that the temperature of the cold plate 3 is a ′ ° C. in that case. . In this case, Peltier 2
The calculation of the temperature 2 is performed by tabulating the relationship between the preset Peltier temperature and the cold plate temperature.

FIG. 3 is a graph showing a correlation table between the Peltier temperature and the cold plate temperature. In the above example, the control temperature of the Peltier is c ° C.

The dry air emitting section 15 is provided with the dry air generator 1.
Dry air 8 supplied from 7 is uniformly blown out from the tray carry-in port 6 and the tray carry-out port 7 to the outside, and in particular, at a constant low temperature, external moisture is prevented from entering the inside and forming dew.

The dry air supply section 16 for adjusting the internal pressure prevents the internal air from leaking to the outside due to the viscosity of the dry air 8 blown out from the dry air emitting section 15 and lowering the internal pressure. There is no wind around 2.

The tray transport rail drive unit 19 is connected to the measurement start signal generation unit 21 and the measurement probe drive unit 14,
When the measurement start signal and the measurement probe upper alignment completion signal are valid, the tray 1 containing the device under test 2 is carried in from the tray carry-in entrance 6 and is conveyed to a position reaching above the cooling plate 3, where the tray conveyance is completed. Output a signal.

The measuring probe driving unit 14 is connected to the measuring device 13 and the tray conveying rail driving unit 19, and measures up to a position where it contacts the electrode of the device under test 2 when the measurement waiting signal and the tray conveying completion signal are valid. The probe 12 is driven downward to output a measurement probe lower alignment completion signal.

The measuring device 13 is connected to the measuring probe driving section 14 and the measuring probe 12, and performs the measurement based on the electric signal obtained from the measuring probe 12 when the measuring probe lower alignment completion signal is valid, and finishes the measurement. After that, a measurement waiting signal is generated.

The measurement probe drive section 14 determines that the measurement of the device under test 2 has been completed by the validity of the measurement waiting signal, and performs measurement probe 1 measurement to measure the next device under test 2.
2 is moved upward, and an upper alignment completion signal is output.

The tray transport rail drive section 19 determines that the measurement of the first device under test 2 in the transported tray has been completed by the validity of the upper position alignment completion signal, The device 2 is transported to a position where the device under test 2 is measured, and a tray transport completion signal is generated. Similarly, the measurement probe driving unit 14 and the measuring device 13 perform the measurement operation of the second device under test 2.

When the measuring operation is performed for the number of the devices 2 in the tray, the counter in the tray transport rail drive unit 19 and the preset number of the devices 2 in the tray match, so that 1 It is determined that the measurement of the elements 2 for the trays has been completed, and the tray for which the measurement has been completed is carried out from above the Peltier 3 to the position of the tray outlet 7.

As is apparent from the above, the following effects can be obtained in the first embodiment.

One is that the temperature of the device under test 2 can be adjusted with very high accuracy. That is, by using the temperature of the air around the element and the temperature of the cooling plate 3 having a high heat transfer effect of the Peltier 22 to calculate the predicted temperature of the element 2 to be measured, and controlling the temperature of the Peltier to match the command temperature. , Enabling high-precision temperature adjustment.

One is that the amount of heat generated in the Peltier 22 is measured in a state where it is efficiently transmitted to the tray 1 and the device under test 2, so that the power supplied to the Peltier 22 is minimized, and High-precision temperature control of the measuring element 2 is possible. That is, the dry air supply unit 1 for adjusting the internal pressure.
6 is dry air 8 blown out from the dry air emitting portion 15
Prevents the air inside the tank from leaking to the outside and lowering the internal pressure, and keeps the vicinity of the Peltier 22 in a windless state. As a result, heat loss due to convection of air around the element is suppressed, so that power supplied to the Peltier is small. Also, by eliminating the temperature fluctuation of the air due to convection,
Since the temperature fluctuation of the device under test 2 is also suppressed, the temperature of the device under test 2 can be adjusted with high accuracy.

One is that there is no condensation during low temperature measurement. That is, the dry air 8 is uniformly blown from the dry air emitting portion 15 to the outside of the measuring tank 5 at the tray carrying-in port 6 and the tray carrying-out port 7 through which air can enter and exit the inside and outside of the measuring tank 5. Is performing the measurement operation. for that reason,
Even if the tray 1 is loaded and unloaded, moisture outside the tank does not enter the tank.

Another is that the size of the apparatus can be reduced. That is, since the air temperature is not adjusted,
There is no need to use a thermostat with a particularly high heat insulating effect. Also, special hardware for adjusting the temperature of the air is not required.

On the other hand, the manufacturing cost of the apparatus can be reduced. That is, since the air temperature is not adjusted,
There is no need to use a thermostat with a particularly high heat insulating effect. Also, no special hardware for adjusting the temperature of the air is required.

On the other hand, the present invention is not limited to the above-described first embodiment, and the following other embodiments are also possible.

As the second embodiment, in the first embodiment shown in FIG. 1, the case where the number of Peltiers is three is shown. However, when the element size is small, the number of Peltiers is It may be one or two. When the element size is large, the Peltier number is not particularly limited.

Further, by performing preheating by increasing the number of Peltiers installed, the temperature of the element is sufficiently adjusted before measurement, so that a new effect that the time required to reach the command temperature can be shortened is obtained. Have.

In the third embodiment, the temperature control unit of the Peltier is provided with fuzzy control instead of PID control. In this case, when the number of Peltiers to be controlled is large, temperature fluctuates due to the influence of the difference in Peltier characteristics in general PID control, and fuzzy control is used when the temperature in the cooling plate cannot be controlled uniformly. This has a new effect that the temperature in the cooling / heating plate can be uniformly controlled.

In the fourth embodiment, the elements are directly transported without using a tray for transporting the elements. In this case, by transporting the element directly to the cooling plate,
There is a new effect that the amount of heat of the Peltier is efficiently transferred to the element and the time required to reach the command temperature can be shortened.

Further, in the fifth embodiment, a plurality of measuring tanks shown in FIG. 1 are arranged side by side, and a communication function is provided between measuring instruments. In this case, by arranging a plurality of measuring tanks and changing the command temperature for each tank, there is a new effect of continuously measuring the electrical characteristics at a plurality of temperatures in a short time. There is no limit on the number of devices.

[0054]

As described above, the method for measuring low- and high-temperature electrical characteristics according to the present invention controls the temperature of the cold plate transmitted from the thermoelectric element utilizing the Peltier effect, and stores the heat of the cold plate in the receiving tray. By transferring heat to the device under test through the, the temperature of the device under test is adjusted at a low or high temperature to measure the electrical characteristics, and the device under test is carried in and out of the measuring tank through the receiving tray, After setting in the chamber, the air temperature in the chamber and the temperature of the cooling plate around the element to be measured in the semiconductor device and the like are detected, and the predicted temperature of the element to be measured is calculated based on the air temperature in the chamber and the temperature of the cooling plate. The temperature of the thermoelectric element is controlled so that the predicted temperature matches a preset temperature.

At this time, an air curtain is formed and shielded from the outside air of the tank to maintain the air convection in a windless state.
In particular, when a low temperature is set, the penetration of moisture from the outside of the tank is blocked by an air curtain to prevent dew condensation inside the tank. By maintaining air convection around the device under test in a windless state, it is possible to suppress heat loss, reduce power supplied to the thermoelectric device, suppress temperature fluctuations of the device under test, and increase temperature adjustment accuracy. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a low- and high-temperature electrical characteristic measuring device according to the present invention.

FIG. 2 is a graph showing the correlation between the air temperature in the tank and the temperature of the cold plate in adjusting the temperature of the device under test.

FIG. 3 is a graph showing a correlation between a cold plate temperature and a Peltier temperature in a table.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 accommodation tray for Peltier transport 2 element to be measured 3 cold plate 4 temperature control unit 5 measurement tank 6 tray carry-in 7 tray carry-out 8 dry air 9 temperature sensor for cold plate 10 temperature sensor for air in chamber 11 element temperature Calculation unit 12 Measurement probe 13 Measuring device 14 Measurement probe drive unit 15 Dry air emission unit 16 Dry air supply unit for adjusting tank internal pressure 17 Dry air generation unit 18 Tray transport rail 19 Tray transport rail drive unit 20 Element temperature command unit 21 Measurement Start signal generator 22 Peltier (thermoelectric element)

Claims (14)

[Claims] An element to be measured is carried in and out of a measuring tank via a storage tray, and the temperature of a cold plate transmitted from a thermoelectric element utilizing the Peltier effect is controlled to transfer the heat of the cold plate to the storage tray. A method for measuring electrical characteristics by adjusting the temperature of the device under test at a low or high temperature by transferring heat to the device under test through the device, and setting the device under test. Detecting the temperature of the air inside the bath and the temperature of the cooling plate, calculating the predicted temperature of the device under test based on the temperature of the air in the bath and the temperature of the cooling plate, and setting the predicted temperature to a preset value. A low- and high-temperature electrical characteristic measuring method, wherein the temperature of the thermoelectric element is controlled so as to match the temperature. 2. A correlation between the air temperature in the bath, the temperature of the cold plate and the set temperature is tabulated, and a cold plate temperature is determined for the set temperature and the air temperature in the bath with reference to the table. The method for measuring low- and high-temperature electrical characteristics according to claim 1, wherein: 3. The thermoelectric element temperature according to claim 2, wherein a correlation between the temperature of the cold plate and the temperature of the thermoelectric element is tabulated, and the thermoelectric element temperature is calculated for the calculated cold plate temperature. High temperature electrical property measurement method. 4. An air convection around the element to be measured is maintained in a windless state, so that heat loss is suppressed, power supplied to the thermoelectric element is reduced, and temperature fluctuation of the element to be measured is suppressed. 2. The adjustment accuracy is increased.
4. The method for measuring low- and high-temperature electrical properties according to any one of claims 1 to 3. 5. An air curtain is formed to shield air from the outside of the tank so that air convection is maintained in a windless state. In particular, when a low temperature is set, intrusion of moisture from outside of the tank is blocked by the air curtain. 5. The method for measuring low-temperature and high-temperature electrical characteristics according to claim 4, wherein the dew condensation is prevented. 6. The method for measuring low- and high-temperature electrical characteristics according to claim 5, wherein the air curtain is formed by dry air at the loading / unloading port of the storage tray provided in the measuring tank. 7. The device according to claim 1, wherein a measuring probe is brought into contact with the device under measurement in an atmosphere whose temperature is adjusted to a predetermined temperature, and electrical characteristics of the device under measurement are measured. The method for measuring low-temperature and high-temperature electrical characteristics according to any one of the above. 8. The device to be measured is carried in and out of the measuring tank via the storage tray, and the temperature of the cooling panel transmitted from the thermoelectric element utilizing the Peltier effect is controlled to transfer the heat of the cooling plate to the storage tray. A low- and high-temperature electrical characteristic measuring device for measuring the electrical characteristics by controlling the temperature of the device under test at a low or high temperature by transferring heat to the device under test through the device; A chamber air temperature sensor for detecting an air temperature, a cold plate temperature sensor for detecting the temperature of the cold plate, and a predicted temperature of the element to be measured based on the detection signals of the inside air temperature and the cold plate temperature. An element temperature calculating section to calculate, an element temperature command section for presetting a predicted temperature of the device to be measured, a predicted temperature calculated value signal output from the element temperature calculating section, and the element temperature command section. It is compared with the predicted temperature setting signal output, so that the predicted temperature matches the set temperature,
A low- and high-temperature electrical characteristic measuring device, comprising: a temperature controller that sends a command signal to the thermoelectric element to adjust the temperature. 9. A correlation between the in-chamber air temperature, the cold / hot plate temperature, and the set temperature is tabulated, and the element temperature calculating section refers to the table to determine a correlation between the set temperature and the in-chamber air temperature. The low- and high-temperature electrical characteristic measuring apparatus according to claim 8, wherein the temperature of the cold plate is determined. 10. A correlation between the temperature of the cold plate and the temperature of the thermoelectric element is tabulated, and the temperature control unit obtains the temperature of the thermoelectric element with respect to the calculated temperature of the cold plate. The low- and high-temperature electrical characteristic measuring device according to claim 9. 11. A dry air emitting section for forming an air curtain for maintaining the air convection around the element to be measured in a windless state by injecting dry air into and out of the loading / unloading port of the storage tray provided in the measuring tank. The low- and high-temperature electrical characteristic measuring device according to any one of claims 8 to 10, further comprising: 12. A dry air supply section for supplying dry air for preventing a decrease in the tank internal pressure is disposed further inside the tank than a position where the dry air emitting section is provided. 12. The low- and high-temperature electrical characteristic measuring device according to 11. 13. A measuring probe for measuring an electric characteristic of the device under measurement by touching the device under measurement in an atmosphere adjusted to a predetermined temperature, and receiving an electric signal from the measurement probe. The low- and high-temperature electrical characteristic measuring apparatus according to any one of claims 8 to 12, further comprising a measuring device to be measured and a probe driving unit for vertically moving the measuring probe. 14. A plurality of the devices under test accommodated and conveyed in the accommodation tray, and the size of the cold plate is determined according to the shape and size of the devices under test. The number and the shape of the thermoelectric elements are determined in accordance with the following.
14. The low- and high-temperature electrical characteristic measuring device according to any one of 13.