JP2001004718A - Cooling apparatus for semiconductor device testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the variation of a delayed amount resulting from the short- period temperature fluctuation of a refrigerant caused by the turning on/off of a cooler. SOLUTION: In a cooling apparatus, a cooled refrigerant from a cooler 16 is dividedly supplied to the pipes 15 of boards 11 through a pipe 17, and the pipes 15 are respectively passed through superconducting blocks 14 which are in contact with IC elements 12 on the boards 11. The temperatures of the refrigerant at the entrances of the pipes 15 are detected by means of a temperature sensor 21 and the detected temperatures are inputted to a control section 22. The control section 22 makes the detected temperatures of the temperature sensor 21 constant by controlling the heating by means of a heater 23 provided near a refrigerant supplying section to the pipes 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device which cools a refrigerant on and off by a cooler and maintains an electronic circuit in a semiconductor test apparatus at a substantially constant temperature by the refrigerant.

[0002]

2. Description of the Related Art In a semiconductor test apparatus, a test signal is generated from a reference clock signal generated from a timing generator through an electronic circuit including many IC circuits such as a timing adjustment circuit and a waveform shaping circuit, and a test target signal is generated by a driver. Applied to the IC element. The propagation delay time of the electronic circuit has a large temperature-dependent coefficient. If the rise or fall timing of the test signal fluctuates due to the temperature fluctuation, a correct test cannot be performed.

For this reason, the delay time in the path of each test signal is measured at regular time intervals, and the delay time is corrected. In addition, the temperature of the semiconductor test apparatus is controlled by a cooler so as not to be affected by the fluctuation of the ambient temperature. That is, FIG.
As shown in FIG. 3, a heat conductive block 14 made of a metal material is brought into contact with each IC element 12 on each wiring board 11 via a heat conductive agent 13 such as grease or gel having high heat conductivity. A pipe 15 is inserted through the pipe 15, and both ends of each pipe 15 are connected to a refrigerant supply pipe 17 and a refrigerant recovery pipe 18 of a cooler 16. The cooler 16 internally detects the temperature of a refrigerant such as water or Freon, and controls the cooling operation on and off so that the temperature falls within a predetermined range. The temperature-controlled refrigerant passes through the pipe 15,
The heat conduction block 14 is maintained at the temperature of the refrigerant, and the IC element 1
2 is also kept close to the refrigerant temperature.

[0004]

Since the temperature control by the cooler 16 is an on-off control, when the temperature of the refrigerant reaches T1 ° C., the cooling operation is started and the temperature of the refrigerant gradually decreases.
When the temperature reaches T2 ° C., the cooling operation is stopped, the temperature of the refrigerant gradually rises, and when the temperature reaches T1 ° C., the cooling operation is started again. The temperature changes in a triangular shape, and the IC element 12 almost follows the temperature change, and the delay time changes. The delay time fluctuation caused by the temperature fluctuation in a short cycle cannot be corrected by the correction based on the measurement of the delay time at regular time intervals.

[0005] Even with such a relatively small temperature fluctuation, the delay time fluctuates by about several tens of pS / ° C, so that it cannot be ignored in a high-accuracy test, particularly a test for a high-speed device. An object of the present invention is to eliminate a state in which a relatively small but rapid temperature change occurs in a short cycle, to enable a high-accuracy test with a small delay time error, and to provide a semiconductor test apparatus suitable for high-speed device testing. It is to provide a cooling device.

[0006]

According to the present invention, a temperature sensor is provided around an electronic circuit in a semiconductor test apparatus,
A heater for heating a pipe through which a coolant for cooling the electronic circuit is provided is provided near the electronic circuit, and the heater is controlled by control means so that the temperature of the coolant in the pipe for cooling the electronic circuit becomes substantially constant. You.

[0007]

FIG. 1 shows an embodiment of the present invention.
Parts corresponding to those in FIG. 4 are denoted by the same reference numerals. In this embodiment, the IC elements 12 mounted on a plurality of boards 11
The pipes 15 for the heat conduction block 14 for cooling the pipes are branched, and the pipes 15 are closest to the board 11 on the side of the cooler 16, that is, near the inlet of the pipes 15 for the nearest electronic circuit of the supply pipes 17. Temperature sensor 2
1 is provided to the output control unit 22 of the temperature sensor 21, and the refrigerant supplied to the pipe 15 branched to the electronic circuit is controlled by the heater 23 by the output of the control unit 22.
The temperature detected by the temperature sensor 21 is set to a predetermined value. A portion of the supply pipe 17 close to the closest branch pipe 15 is enlarged to be a small tank 24, and a heater 23 is provided to heat the small tank 24.

[0008] The temperature sensor 21 is a thermistor, a thermocouple, or the like, and detects the temperature of the pipe 17. Temperature sensor 21
May be directly disposed in a coolant such as water or Freon. The temperature detected by the temperature sensor 21 is compared with a predetermined temperature set in advance by the control unit 22, and the heater 23 is controlled so that the temperature detected by the temperature sensor 21 becomes a predetermined value. Heater 23
Is a heating wire such as a nichrome wire, and the heating control is performed in an analog manner. As the control unit 22, a so-called temperature controller can be used.

According to this configuration, the temperature of the refrigerant flowing into the small tank 24 fluctuates by about 2 ° C. in a cycle of several minutes, for example, by turning on / off the operation of the cooler 16.
The refrigerant flowing out of the small tank 24 is controlled to a substantially constant temperature by the above control. Since the refrigerant having the constant temperature is supplied to each pipe 15, each IC element 12 is cooled to a constant temperature via the heat conduction block 14, and the IC element 12 is maintained at the constant temperature.

FIG. 2 shows another embodiment of the present invention.
The same reference numerals are given to portions corresponding to. In this embodiment, the temperature sensor 21 flows out of each pipe 15 and flows into the recovery pipe 18. It is provided near the entrance of the collection pipe 18. The temperature of the end of the pipe 15 of the supply pipe 17 that supplies the refrigerant to the pipe 15 via the control unit 22 is controlled by the heater 23 in accordance with the temperature detected by the temperature sensor 21.

Also in this case, the fluctuation of the refrigerant temperature is detected by the temperature sensor 2
1, the heating control for the heater 23 is performed so that the refrigerant temperature does not fluctuate, and each IC element 12 is maintained at a predetermined temperature. In this case, the temperature of each of the boards 11 further varies due to the influence of the ambient temperature as a whole, and the power consumption of the IC elements 12 on each of the boards 11 varies uniformly to cause a temperature variation as a whole. These temperature fluctuations are also detected by the temperature sensor 21, the heating of the heater 23 is controlled so as to suppress these temperature fluctuations, and the fluctuation of the delay amount based on the fluctuation of the ambient temperature and the power consumption of the electronic components. Is suppressed.

FIG. 3 shows still another embodiment of the present invention.
Parts corresponding to those in FIGS. 1 and 2 are given the same reference numerals. In this embodiment, each board 11 has its pipe 15
A temperature sensor 21 is provided near the refrigerant outlet of the
A heater 23 is provided in the vicinity of the refrigerant inflow port, and the temperature of the refrigerant flowing out therefrom is detected for each of the boards 11 and the temperature of the inflowing refrigerant is controlled by the heater 23 so that this temperature is maintained at a predetermined value. Controlling. Therefore, the temperature fluctuation of the refrigerant due to the turning on and off of the operation of the cooler 16 is suppressed in the same manner as in the above-described embodiment, and the fluctuation of the ambient temperature for each board 11 and the fluctuation of the power consumption of the electronic components on the board 11 Temperature fluctuations of electronic components are also suppressed.

As the temperature sensor 21, a semiconductor diode may be incorporated in the IC element 12 near the refrigerant outflow side of the board 11, a constant current may flow through the diode, and the temperature may be detected according to the voltage drop of the diode. it can.

[0014]

As described above, according to the present invention, the fluctuation in the temperature of the refrigerant due to the on / off operation of the cooler is suppressed, and the refrigerant is supplied to the electronic component board at a substantially constant temperature. The delay amount can be determined with high accuracy, and therefore, a test for a high-speed device can be performed.

According to the embodiment shown in FIG. 3, it is possible to suppress the influence of the fluctuation of the ambient temperature for each board and the fluctuation of the power consumption of the electronic components.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing another embodiment of the present invention.

FIG. 3 is a diagram showing still another embodiment of the present invention.

FIG. 4 is a diagram showing a conventional cooling device.

Claims (4)

[Claims] 1. A cooling device for cooling a refrigerant, which is cooled by passing the refrigerant through a pipe along a board on which an electronic circuit of a semiconductor test device is mounted, so that the temperature of the refrigerant is substantially constant by the cooling device. A cooling device for a semiconductor test apparatus that controls on / off of a cooling operation, a temperature sensor provided around the electronic circuit, a heater that heats the pipe around the electronic circuit, and a pipe inside the pipe that cools the electronic circuit. Means for controlling the heating of the heater so that the temperature of the refrigerant is substantially constant. A cooling device for a semiconductor test device, comprising: 2. The temperature sensor is provided so as to detect a temperature near a refrigerant inlet of the pipe with respect to the electronic circuit, and the heater is also provided near a refrigerant inlet of the pipe. A cooling device for a semiconductor test apparatus according to claim 1. 3. The temperature sensor is provided to detect a temperature near a refrigerant outlet of the pipe with respect to the electronic circuit, and near a refrigerant inlet of the pipe with respect to the electronic circuit.
The said heater is provided, The Claim 1 characterized by the above-mentioned.
A cooling device for a semiconductor test apparatus according to the above. 4. The temperature sensor is provided for each board so as to detect a temperature near a refrigerant outlet of the pipe, and the heater is provided near a refrigerant inlet of the pipe of the corresponding board. The cooling device for a semiconductor test device according to claim 1, wherein: