JP2007183167A - Device evaluation system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device evaluation system and a device evaluation method allowing to inspect the durability of a device which is used in a higher temperature range than ever before. <P>SOLUTION: The evaluation system 30 comprises an electronic cooling element (a Peltier element 9), a heat radiation member (a radiator 11), a coolant channel 13, a heat exchanger 15, a pump 14, a coolant 17, and a control section (a controller 29). The Peltier element 9 is thermally connected to an object under measurement 1 including a semiconductor device. The radiator 11, coolant channel 13, heat exchanger 15, and pump 14 are thermally connected to the Peltier element 9. The controller 29 controls power to be input to the object under measurement 1 and the Peltier element 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a device evaluation apparatus and a device evaluation method, and more specifically to a device evaluation apparatus and a device evaluation method that can evaluate a device in a higher temperature region than in the past.

Conventionally, a power device for high withstand voltage and high power is known as one of the uses of a semiconductor device. Currently, devices using silicon (Si) are mainly used as such power devices, but devices using SiC have also been proposed as higher performance devices (see, for example, Non-Patent Document 1). ). Since such a power device has a relatively high temperature during use, a durability test (thermal cycle test) against a stress caused by a difference in thermal expansion coefficient between mounting materials of the device is performed.
Hisashi Kawai, “Expectations for SiC devices from the perspective of automotive electronics”, FED Review, New Functional Device Research and Development Association, Vol. 1 2002

  The above-described thermal cycle test is defined in JIS C7021. However, the thermal cycle test currently being conducted is premised on a device using Si, and is intended to guarantee the guaranteed operating temperature range (-40 to 150 ° C.) of the device using Si. .

  On the other hand, when the above-described device using SiC is used as a power device, an operation in a higher temperature range (for example, a temperature range of 200 ° C. or higher) is assumed. However, since the conventional evaluation apparatus and evaluation method for performing a thermal cycle test do not assume such a test in a high temperature range, a device (for example, using SiC) that is used in a higher temperature range than a device using Si is used. It was difficult to sufficiently conduct a thermal cycle test for verifying the durability of the device.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a device evaluation apparatus and device evaluation capable of verifying the durability of a device used in a higher temperature range than before. Is to provide a method.

  A device evaluation apparatus according to the present invention includes an electronic cooling element, a heat radiating member, and a control unit. The electronic cooling element is thermally connected to a measurement object including a semiconductor device. The heat radiating member is thermally connected to the electronic cooling element. A control part controls the electric power input into a to-be-measured object and an electronic cooling element.

  In this way, by inputting electric power to the measured object itself, the measured object itself can generate heat, and the temperature of the measured object including the semiconductor device can be raised, so that the measured object is heated from the outside. Therefore, the thermal cycle test can be performed under conditions closer to the actual operating conditions of the object to be measured. Therefore, even when the semiconductor device of the device under test operates at a higher temperature range than a device using conventional silicon such as a device using SiC, the operating temperature range of the device under test (higher temperature range than before) The test in can be easily performed.

  Further, since the measured object itself is used as a heating element, it is not necessary to arrange a heating device such as a heater in the device evaluation apparatus itself. For this reason, the apparatus configuration of the device evaluation apparatus can be simplified.

  Here, the semiconductor device means a device using a semiconductor such as silicon (Si) or silicon carbide (SiC) as a substrate. In addition, the object to be measured is a single semiconductor device, a semiconductor package in which the semiconductor device is incorporated, or a combination of a plurality of components to realize a predetermined function using the semiconductor device as a part of the component. It may be a module configured as described above. In addition, “thermally connecting” the above-described electronic cooling element and the measured object means that the electronic cooling element and the measured object are connected so that heat can be transferred between the electronic cooling element and the measured object. Directly connecting the electronic cooling element and the object to be measured via a member capable of transferring heat, and the heat between the electronic cooling element and the object to be measured. Any connection method may be used as long as transmission is possible.

  In addition, the thermoelectric cooling element is an element that can make a difference in temperature on different surfaces (both sides) of the element by applying power, or one of the different surfaces of the element that absorbs heat, and the other surface. It means an element that generates heat and can act as a heat pump as a result, and specifically includes a Peltier element.

  A device evaluation method according to the present invention is a device evaluation method using the device evaluation apparatus, and includes a step of thermally connecting a measurement object to an electronic cooling element and a test step. In the test process, by inputting electric power to the object to be measured, a heating process for increasing the temperature of the object to be measured, and transferring heat to the object to be measured by inputting electric power to the electronic cooling element, The power is controlled by the control unit so that the cooling process for cooling the measurement object is repeated one or more times.

  In this way, the temperature of the measured object is raised using the heat generated from the measured object itself, while the heat of the measured object is transmitted to the heat radiating member by the electronic cooling element, thereby A thermal cycle test can be easily performed.

  As described above, according to the present invention, since the thermal cycle test can be performed under conditions close to the actual operating conditions of the measured object, the semiconductor device of the measured object is a conventional silicon like a device using SiC. Even when the device operates in a higher temperature range than the device using the device, the test in the operating temperature range of the object to be measured can be easily performed.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a schematic diagram of Embodiment 1 of an evaluation apparatus according to the present invention. With reference to FIG. 1, Embodiment 1 of the evaluation apparatus according to the present invention will be described.

  As shown in FIG. 1, an evaluation apparatus 30 as a device evaluation apparatus according to the present invention includes a Peltier element 9 as an electronic cooling element that is thermally connected to a measurement object 1 including a semiconductor device, and a Peltier element 9. And a heat radiator 11 as a heat radiating member thermally connected to each other, and a control device 29 as a control unit that controls electric power input to the measured object 1 and the Peltier element 9. More specifically, the DUT 1 is connected to the base plate 5 via grease. A groove is formed in a region of the surface of the base plate 5 located under the measured object 1, and a thermocouple 7 for measuring the temperature of the measured object 1 is disposed in the groove. The size of the planar shape of the base plate 5 is larger than the size of the planar shape of the DUT 1. Moreover, as a material which comprises the baseplate 5, what kind of material may be used if it is a material which can perform heat transfer efficiently. For example, the base plate 5 may be made of metal such as aluminum, copper, or an alloy containing these.

  In addition, as a method of measuring the temperature of the device under test 1, a method using a non-contact type thermometer (for example, an infrared thermometer) instead of the thermocouple 7, or a diode Vf included in the device under test 1 ( A method of measuring a forward voltage) may be used. In this case, for example, if it is a non-contact thermometer, it can be arranged at an arbitrary position facing the measured object 1.

  The lower surface of the base plate 5 is connected to the upper surface of the Peltier element 9 via the grease 3. The lower surface of the Peltier element 9 is connected to the radiator 11 through the grease 3. Further, the Peltier element 9 is formed with a flange portion 10 protruding outward on the outer peripheral portion thereof. A screw hole is formed in the flange portion 10. A fixing screw 12 is inserted into the screw hole. The tip of the fixing screw 12 is inserted and fixed in a fixing hole formed in the upper surface of the radiator 11. In other words, the fixing screw 12 is inserted and fixed in the screw hole of the flange portion 10 of the Peltier element 9 and the fixing hole on the upper surface of the radiator 11, thereby connecting and fixing the Peltier element 9 and the radiator 11. ing.

  The heat radiator 11 has a flat upper surface, and a plurality of heat radiating fins serving as heat radiating portions as shown in FIG. As a material constituting the radiator 11, any material may be used as long as the material can efficiently perform heat transfer. For example, the radiator 11 may be made of metal such as aluminum, copper, or an alloy containing these elements. In addition, a refrigerant flow path 13 is connected to the radiator 11 in order to supply a refrigerant 17 for contacting the radiating fin and removing heat from the radiator 11. The refrigerant flow path 13 constitutes a circulation path that connects the other end of the radiator 11 from one end of the radiator 11 via the pump 14 and the heat exchanger 15.

  By driving the pump 14, the refrigerant 17 flows from one end of the radiator 11 so as to contact the radiating fins of the radiator 11, for example. When the refrigerant 17 comes into contact with the radiating fin, the refrigerant 17 takes heat from the radiator 11. Then, after the refrigerant 17 reaches the other end of the radiator 11, the refrigerant 17 flows from the other end of the radiator 11 through the refrigerant flow path 13 and reaches the heat exchanger 15. In the heat exchanger 15, the refrigerant 17 is cooled as a result of heat exchange between the refrigerant 17 and another medium (for example, outside air). After the refrigerant 17 that has passed through the heat exchanger 15 reaches the pump 14, it is supplied again to one end of the radiator 11 by driving the pump 14. As shown in FIG. 1, a temperature sensor 16 for measuring the temperature of the refrigerant 17 is disposed in a portion of the refrigerant flow path 13 located on the downstream side of the radiator 11.

  In order to fix the positions of the radiator 11, the Peltier element 9, and the base plate 5, a plurality of fixing members 20 are arranged. The fixing member 20 includes pressing members 18 a and 18 b and a support member 19. The pressing member 18a has a plate-like or bar-like shape arranged so as to extend in the same direction as the direction in which the upper surface of the base plate 5 extends. The presser member 18a is arranged so that one end of the presser member 18a contacts the end of the upper surface of the base plate 5. The pressing member 18b has a plate-like or bar-like shape that is arranged to extend in the same direction as the direction in which the upper surface of the radiator 11 extends. The holding member 18b is arranged so that one end of the holding member 18b contacts the outer wall surface of the refrigerant flow path 13 at the lower part of the radiator 11.

  A support member 19 for connecting and fixing the presser members 18a and 18b is connected to the other ends of the presser members 18a and 18b. The support member 19 connects the presser members 18a and 18b, and can press the presser members 18a and 18b in a direction approaching each other. For example, a hole for inserting the support member 19 is formed in the other end of the pressing members 18a and 18b, and the end of the support member 19 is inserted into the hole. And while forming a screw groove in the edge part of the supporting member 19, the fixing members, such as a nut, are screwed in from the said edge part side, and the pressing members 18a and 18b are pressed in the direction which mutually approaches. In this manner, the positions of the radiator 11, the Peltier element 9, and the base plate 5 can be fixed by the fixing member 20.

  Further, a sealed case 28 is arranged so as to hold the device under test 1, the base plate 5, the Peltier element 9, the radiator 11, and the fixing member 20 inside. The hermetic case 28 is configured so that its inside can be isolated from the outside. As the material constituting the sealed case 28, any material may be used as long as the inside can be isolated from the outside and the material is resistant to the atmospheric gas disposed inside.

  Although not shown, an exhaust pump as a pressure adjusting member for adjusting the internal pressure may be connected to the sealed case 28 via a pipe. The sealed case 28 is used as an atmosphere gas supply member for supplying a predetermined atmosphere gas (for example, an inert gas such as argon gas or nitrogen gas, or dry air for preventing condensation) to the inside of the sealed case 28. A mass flow controller may be connected via piping. The mass flow controller may be connected to the supply source of the atmospheric gas (for example, a tank for storing the atmospheric gas) via another pipe.

  The evaluation device 30 includes a control device 29 for controlling the power supplied to the Peltier element 9, the DUT 1, the pump 14, the heat exchanger 15, and the like described above. The control device 29 includes a measured object power supply 21, a measured object heating power supply 22, a Peltier element power supply 23, a cooling system power supply 24, and a controller 26 for controlling these power supplies. The control device 29 may be configured by a dedicated control board equipped with a microcomputer that operates as the controller 26, various power sources, various switches, and the like. You may comprise by the apparatus connected and mounted with various power supplies, various switches, etc. The power supply 21 for the measured object and the power supply 22 for the measured object heating are connected to the measured object 1 via the current sensor 25 via connection lines. The Peltier element power source 23 is connected to the Peltier element 9 via a current sensor 25 via a connection line. The cooling system power supply 24 is connected to each of the pump 14 and the heat exchanger 15 via a current sensor 25. If the heat exchanger 15 is configured not to be driven by electric current, the cooling system power supply 24 may be connected only to the pump 14. In addition, the above-described power supply 21 to be measured, power supply 22 to be measured heat source, Peltier element power supply 23 and cooling system power supply 24 include control circuits for performing PWM control and voltage control, which will be described later, respectively. It is a waste.

  In addition, PWM control (Pulse Width Modulation control) here means pulse width modulation control, and here, the voltage of the current input to the measurement object 1 is changed to a pulse waveform that repeats ON and OFF, and the pulse wave The electric power input to the object to be measured is controlled by changing the ratio between ON and OFF (pulse width). Moreover, voltage change control means control which changes the value of the voltage of the electric current input into the to-be-measured object 1 with time here.

  Each of the measurement object power supply 21, the measurement object heating power supply 22, the Peltier element power supply 23, and the cooling system power supply 24 described above is connected to the controller 26 and controlled by the controller 26. The controller 26 is connected to a temperature sensor 16 that measures the temperature of the refrigerant 17 and a thermocouple 7 that measures the temperature of the DUT 1. The controller 26 receives temperature measurement data from the temperature sensor 16 and the thermocouple 7. The controller 26 uses these measurement data to control the evaluation device 30.

  Next, the operation of the evaluation apparatus 30 will be described by taking as an example a device evaluation method (thermal cycle test) of the device under test 1 using the evaluation apparatus 30 shown in FIG. FIG. 2 is a flowchart showing a device evaluation method using the evaluation apparatus shown in FIG. FIG. 3 is a flowchart showing the contents of the test process in the flowchart shown in FIG. A device evaluation method using the evaluation apparatus shown in FIG. 1 will be described with reference to FIGS.

  As shown in FIG. 2, the device evaluation method using the evaluation apparatus 30 shown in FIG. 1 includes a measured object preparation step (S100), a test step (S200), and a post-processing step (S300). In the measurement object preparation step (S100), the measurement object 1 such as a module including a semiconductor device is disposed via a grease 3 at a predetermined position on the base plate 5 shown in FIG. Further, by sealing the sealed case 28, the outside of the sealed case 28 and the inside of the sealed case 28 in which the measured object 1 is arranged are isolated, and the composition and pressure of the atmospheric gas inside the sealed case 28 are set. Adjust to predetermined conditions.

  Next, a test process (S200) is performed. Specific contents of this test step (S200) will be described later. And after a test process (S200) is complete | finished, a post-processing process (S300) is implemented. Specifically, the device under test 1 for which the test has been completed is taken out from the base plate 5.

  Next, the specific content of the test step (S200) will be described with reference to FIG. As shown in FIG. 3, in the test step (S200) (see FIG. 2), first, the temperature of the object to be measured 1 is raised to a predetermined temperature and then maintained at that temperature (maintenance temperature on the high temperature side) for a predetermined time. A temperature raising step (S210) is performed. In this temperature raising step (S210), specifically, the measured object 1 is caused to generate heat by supplying electric power to the measured object 1 from the measured object heating power source 22 (see FIG. 1). At the same time, the supply of power from the Peltier element power supply 23 is stopped for the Peltier element 9. As a result, the amount of heat generated from the device under test 1 becomes larger than the amount of heat removed from the device under test 1 via the base plate 5 and the Peltier element 9, so that the temperature of the device under test 1 can be raised. Further, when the temperature of the device under test 1 is kept constant at the high temperature side maintenance temperature, by controlling the power output from the device under test heating power source 22 or the Peltier element power source 23 as described later, It becomes possible to keep the temperature of the DUT 1 constant at the above maintenance temperature.

  Next, a cooling step (S220) is performed. In the cooling step (S220), the temperature of the measurement object 1 maintained for a certain period of time at the above-described high temperature side maintenance temperature is lowered and maintained at a predetermined temperature (low temperature side maintenance temperature) for a predetermined time. Specifically, as will be described later, the temperature of the device under test 1 is controlled by controlling the power output from the power source 23 for the Peltier element while stopping or reducing the output of the power from the device heat generating power source 22. Can be maintained at the maintenance temperature on the low temperature side.

  Next, a step (S230) of determining whether the temperature raising and cooling have been repeated a predetermined number of times is performed. In this step (S230), it is determined whether or not the temperature raising step (S210) and the cooling step (S220) described above have been repeated a predetermined number of times, and when it is determined that the predetermined number of times has not been repeated (when NO is determined). The temperature raising step (S210) and the cooling step (S220) are performed again. Further, when it is determined that the above process has been repeated a predetermined number of times in the step (S230) (when it is determined YES), the measurement target heating power source 22, the Peltier element power source 23, and the like are turned off. A post-processing step (S240) is performed. In this way, the test process (S200) can be performed.

  In the temperature raising step (S210) and the cooling step (S220) described above, the temperature of the device under test 1, more specifically, the semiconductor junction temperature Tj of the semiconductor device included in the device under test 1 is set to the high temperature side or the low temperature side. In order to maintain at the maintenance temperature, for example, PWM control or voltage change control can be applied to the output of the power supply 22 for heating the measured object and the power supply 23 for the Peltier element. Hereinafter, a case where PWM control or voltage change control is applied in the test process (S200) will be described.

  In the evaluation apparatus 30 shown in FIG. 1, since the high-temperature thermal cycle test is performed as will be described later, the power supply of the Peltier element 9 is turned off in a state where the semiconductor junction temperature Tj is the high temperature side maintenance temperature Tjmax. From the evaluation device 30 when the power source of the Peltier element 9 is turned off as determined by the cooling capacity (radiation heat transfer, natural convection heat transfer, conduction heat transfer, etc.) The evaluation device 30 is designed such that the calorific value (Qgen) of the measured object 1 is larger than the (radiated heat amount). Further, in order to realize a quick response in time in the high-temperature thermal cycle test, it is effective to increase the calorific value (Qgen) of the measured object 1. Increasing the amount of heat generated (Qgen) of the device under test 1 in this way can be easily realized by increasing the power supply voltage from the power supply 22 for the device under test heating supplied to the device under test 1.

  It is also preferable to increase the amount of heat (Qr) removed from the DUT 1 via the Peltier element 9 and the radiator 11. In particular, considering the thermal circuit of the evaluation device 30, the maintenance temperature Tjmin on the low temperature side of the semiconductor junction temperature Tj greatly depends on the temperature of the refrigerant 17. That is, the low temperature side maintenance temperature Tjmin cannot be lower than the refrigerant temperature.

(Case 1)
In order to control the heat generation amount (Qgen) from the device under test 1, PWM control is applied to the power source 22 for heat generation of the device under test, and PWM control is applied to the power source 23 for the Peltier element, thereby This is a case where the amount of heat (Qr) removed from the DUT 1 via the element 9 and the radiator 11 is controlled. A specific control flow is shown in FIG. 4, and a timing chart showing ON / OFF of the power supply and transition of temperature conditions is shown in FIG. 5. FIG. 4 is a flowchart showing a test process in an example of a device evaluation method according to the present invention. FIG. 5 is a timing chart showing power ON / OFF and temperature condition transition in the test process according to the flowchart shown in FIG. In FIG. 5, the horizontal axis indicates time, and the vertical axis indicates four characteristic values. That is, the vertical axis in FIG. 5 shows the change in the semiconductor junction temperature Tj in the semiconductor device from the top, the change in the temperature of the device under test 1 (monitor temperature Tmon) measured by the thermocouple 7 in FIG. 23 (ON / OFF of 23 (Peltier drive power supply)) and ON / OFF of the measured object heating power supply 22 (semiconductor drive power supply) are shown. With reference to FIG. 4 and FIG. 5, the test process in an example (case 1) of the device evaluation method by this invention is demonstrated.

  Referring to FIGS. 4 and 5, in the test process, first, as a part of the temperature raising process (S210) (see FIG. 3), the semiconductor drive power supply is turned on and the Peltier drive power supply is turned off (S211). To implement. This step (S211) is performed at time T1 in the timing chart of FIG. From this time T1, the monitor temperature Tmon and the semiconductor junction temperature Tj start to rise as shown in FIG. During the test step (S200), the power to be measured 1 is supplied from the power supply for measured object 21 (see FIG. 1) to the measured object 1.

  Then, in step (S212) of FIG. 4, it is determined whether or not the semiconductor junction temperature Tj has reached Tjmax, which is the high temperature side maintenance temperature. In this step (S212), NO is determined from the time point T1 to the time point T2 in FIG. 5, so the step (S212) is repeated until the time point T2 in FIG.

  At time T2 in FIG. 5, the semiconductor junction temperature Tj reaches Tjmax, which is the high-temperature side maintenance temperature, and the monitor temperature Tmon reaches Tmax, which is the high-temperature side maintenance temperature. The semiconductor junction temperature Tj is obtained from the monitor temperature Tmon by calculation. As can be seen from FIG. 5, the maintenance temperature Tmax on the high temperature side of the monitor temperature Tmon is lower than the maintenance temperature Tjmax on the high temperature side of the semiconductor junction temperature Tj. This is because the semiconductor device arranged inside the device under test 1 acts as a heating element, so that the monitor temperature Tmon, which is the measurement temperature outside the device under test 1, is higher than the semiconductor junction temperature Tj in the semiconductor device. This is because it becomes lower.

  As described above, when the semiconductor junction temperature Tj reaches Tjmax at time T2, YES is determined in step (S212), and the next step (S213) is performed. In this step (S213), PWM control of the semiconductor drive power supply is disclosed. Specifically, as shown in FIG. 5, the output of the semiconductor drive power supply has a pulse wave shape by repeating ON / OFF of the semiconductor drive power supply at a predetermined interval. Then, by appropriately controlling the width and interval of the pulse wave (ON time and OFF time), the heat generation amount Qgen from the semiconductor device in the measurement target 1 is suppressed. As a result, the calorific value Qgen from the measured object 1 and the heat quantity Qr transmitted from the measured object 1 to the radiator 11 through the base plate 5 and the Peltier element 9 and removed by the refrigerant 17 have a predetermined balance. . Therefore, as shown in FIG. 5, the monitor temperature Tmon and the semiconductor junction temperature Tj can be maintained at the high temperature side maintenance temperatures Tmax and Tjmax, respectively.

  Then, the state in which the monitor temperature Tmon and the semiconductor junction temperature Tj as described above are kept constant starts at time T2 in FIG. 5 and continues for a predetermined time. At this time, in the control flow shown in FIG. 4, whether a predetermined time has elapsed since the semiconductor junction temperature Tj became Tjmax in the step (S214) (whether the time from time T2 to time T3 has elapsed). To be judged. Since it is determined NO in step (S214) until time T3 in FIG. 5, step (S214) is repeated until time T3. For this reason, the PWM control of the semiconductor drive power supply is continued until time T3, whereby the monitor temperature Tmon and the semiconductor junction temperature Tj are maintained at the high-temperature maintenance temperatures Tmax and Tjmax, respectively.

  When time T3 is reached, YES is determined in step (S214), and therefore the cooling step (S220) in FIG. 3 is started. Specifically, a process (S221) of turning off the semiconductor drive power and turning on the Peltier drive power is performed at time T3 in FIG. As a result, as shown in FIG. 5, the monitor temperature Tmon and the semiconductor junction temperature Tj start to decrease from time T3.

  Thereafter, in the flowchart shown in FIG. 4, it is determined in step (S222) whether or not the semiconductor junction temperature Tj has become the low temperature side maintenance temperature Tjmin. Then, as shown in FIG. 5, until the time T4 when the semiconductor junction temperature Tj becomes the low temperature side maintenance temperature Tjmin (that is, the monitor temperature Tmon becomes the low temperature side maintenance temperature Tmin), NO is determined in the above step (S222). The Therefore, the process (S222) is repeated until the time point T4 is reached.

  Then, at time T4 shown in FIG. 5, when the semiconductor junction temperature Tj reaches the low temperature side maintenance temperature Tjmin, YES is determined in the step (S222). As a result, a step (S223) of starting PWM control of the Peltier drive power supply is performed. When this step (S223) is performed, as shown in FIG. 5, the Peltier drive power supply repeats ON / OFF at a predetermined interval. Specifically, as shown in FIG. 5, ON / OFF of the Peltier drive power supply is repeated at a predetermined interval, so that the output of the Peltier drive power supply has a pulse waveform. The amount of heat Qr transmitted from the base plate 5 side to the radiator 11 side in the Peltier element 9 is controlled by appropriately controlling the width and interval (ON time and OFF time) of the pulse wave. As a result, the calorific value Qgen from the measured object 1 and the heat quantity Qr transmitted from the measured object 1 to the radiator 11 through the base plate 5 and the Peltier element 9 and removed by the refrigerant 17 have a predetermined balance. . Therefore, as shown in FIG. 5, the monitor temperature Tmon and the semiconductor junction temperature Tj can be maintained at the low temperature side maintenance temperatures Tmin and Tjmin, respectively.

  Then, the state in which the monitor temperature Tmon and the semiconductor junction temperature Tj as described above are maintained constant starts at time T4 in FIG. 5 and continues for a predetermined time. At this time, in the control flow shown in FIG. 4, whether a predetermined time has elapsed since the semiconductor junction temperature Tj became Tjmin in the step (S224) (whether the time from time T4 to time T5 has elapsed). To be judged. Until time T5 in FIG. 5 is NO in step (S224), step (S224) is repeated until time T5. For this reason, the PWM control of the Peltier drive power supply is continued until time point T5, whereby the monitor temperature Tmon and the semiconductor junction temperature Tj are maintained at the low temperature side maintenance temperatures Tmin and Tjmin, respectively.

  And when it becomes time T5, it will be judged as YES in a process (S224). As a result, the step (S230) shown in FIG. 4 is performed. In step (S230), it is determined whether the temperature raising step (step (S211) to step (S214)) and the cooling step (step (S221) to step (S224)) have been repeated a predetermined number of times. When it is determined NO in the step (S230), the steps after the step (S211) are sequentially repeated again.

  That is, the temperature raising process is started again from time T5 in FIG. The control started from time T5 is just the same as the control started from time T1. That is, at time T5, a step (S211) of turning on the semiconductor drive power and turning off the Peltier drive power is performed. From this time T5, as shown in FIG. 5, the monitor temperature Tmon and the semiconductor junction temperature Tj start to rise. Then, the process (S212) is repeated until time T6. Further, at time T6, as in the case of time T2, the semiconductor junction temperature Tj reaches Tjmax, which is the high temperature side maintenance temperature, and the monitor temperature Tmon reaches Tmax, which is the high temperature side maintenance temperature. Then, as in the case of time T2, at step T6, YES is determined in step (S212), and step (S213) is performed.

  Further, if it is determined YES in the step (S230), that is, if it is determined that the temperature raising step and the cooling step are repeated a predetermined number of times, the thermal cycle test is ended, so that Peltier driving as post-processing is performed. A step of turning off the power (S241) is performed. In this manner, the test process (S200) in case 1 is performed.

(Case 2)
In order to control the heat generation amount (Qgen) from the measured object 1, the measured object heating power supply 22 is turned on / off, while the Peltier element power supply 23 is applied with PWM control. This is a case where PWM control is applied to the Peltier element power source 23 in order to control the amount of heat (Qr) removed from the DUT 1 via the heat sink 9 and the radiator 11. A specific control flow is shown in FIG. 6, and a timing chart showing ON / OFF of the power supply and transition of temperature conditions is shown in FIG. FIG. 6 is a flowchart showing a test process in an example of a device evaluation method according to the present invention. FIG. 7 is a timing chart showing the transition of power ON / OFF and temperature conditions in the test process according to the flowchart shown in FIG. FIG. 7 is basically shown in the same manner as FIG. 5, where the horizontal axis indicates time and the vertical axis indicates four characteristic values. That is, the vertical axis in FIG. 5 shows the change in the semiconductor junction temperature Tj in the semiconductor device from the top, the change in the temperature of the device under test 1 (monitor temperature Tmon) measured by the thermocouple 7 in FIG. 23 (ON / OFF of 23 (Peltier drive power supply)) and ON / OFF of the measured object heating power supply 22 (semiconductor drive power supply) are shown. With reference to FIG. 6 and FIG. 7, the test process in an example (case 2) of the device evaluation method by this invention is demonstrated.

  6 and 7, in the test process, first, as part of the temperature raising process (S210) (see FIG. 3), the semiconductor drive power supply is turned on, as in the flowchart shown in FIG. A step (S211) of turning off the Peltier drive power is performed. This step (S211) is performed at time T1 in the timing chart of FIG. From this time T1, the monitor temperature Tmon and the semiconductor junction temperature Tj start to rise as shown in FIG. In the case 2, as in the case 1 described above, during the test step (S200), the device under test 1 is required for normal operation from the device under test power supply 21 (see FIG. 1). Power is supplied.

  Then, in step (S212) of FIG. 6, it is determined whether or not the semiconductor junction temperature Tj has reached Tjmax, which is the high temperature side maintenance temperature. In this step (S212), NO is determined from the time point T1 to the time point T2 in FIG. 7, so the step (S212) is repeated until the time point T2 in FIG.

  At time T2 in FIG. 7, the semiconductor junction temperature Tj reaches Tjmax, which is the high temperature side maintenance temperature, and the monitor temperature Tmon reaches Tmax, which is the high temperature side maintenance temperature. Thus, when the semiconductor junction temperature Tj reaches Tjmax at time T2, YES is determined in step (S212), and the next step (S215) is performed. In this step (S215), Peltier drive power supply PWM control is disclosed. Specifically, as shown in FIG. 7, ON / OFF of the Peltier drive power supply is repeated at a predetermined interval, whereby the output of the Peltier drive power supply has a pulse waveform. Then, by appropriately controlling the width and interval (ON time and OFF time) of the pulse wave, the pulse wave is removed from the measured object 1 by the refrigerant 17 via the base plate 5, the Peltier element 9, and the radiator 11. The amount of heat Qr to be controlled is controlled. On the other hand, the measured object 1 continues to generate heat of a predetermined heat generation amount Qgen by the power supplied from the semiconductor drive power supply. As a result, the calorific value Qgen from the measured object 1 and the heat quantity Qr transmitted from the measured object 1 to the radiator 11 through the base plate 5 and the Peltier element 9 and removed by the refrigerant 17 have a predetermined balance. . Therefore, as shown in FIG. 7, the monitor temperature Tmon and the semiconductor junction temperature Tj can be maintained at the high temperature side maintenance temperatures Tmax and Tjmax, respectively.

  Then, the state in which the monitor temperature Tmon and the semiconductor junction temperature Tj as described above are maintained constant starts at a time T2 in FIG. 7 and continues for a predetermined time. At this time, in the control flow shown in FIG. 6, whether a predetermined time has elapsed since the semiconductor junction temperature Tj became Tjmax in the step (S214) (whether the time from time T2 to time T3 has elapsed). To be judged. Until time T3 in FIG. 7 is NO in step (S214), step (S214) is repeated until time T3. For this reason, the PWM control of the Peltier drive power supply is continued until time T3, so that the monitor temperature Tmon and the semiconductor junction temperature Tj are maintained at the high-temperature side maintenance temperatures Tmax and Tjmax, respectively.

  When time T3 is reached, YES is determined in step (S214), and therefore the cooling step (S220) in FIG. 3 is started. Specifically, a process (S221) of turning off the semiconductor drive power and turning on the Peltier drive power is performed at time T3 in FIG. As a result, as shown in FIG. 7, the monitor temperature Tmon and the semiconductor junction temperature Tj start to decrease from time T3. Note that since the Peltier drive power supply is PWM-controlled until time T3, there may be a case where the Peltier drive power supply is in the ON state until immediately before time T3. In this case, the PWM control of the Peltier drive power supply ends at time T3, and the Peltier drive power supply is maintained in the ON state. Also, when the Peltier drive power supply is OFF immediately before time T3, the PWM control of the Peltier drive power supply ends at time T3, and the Peltier drive power supply is switched from the OFF state to the ON state.

  Thereafter, in the flowchart shown in FIG. 6, it is determined in step (S222) whether or not the semiconductor junction temperature Tj has become the low-temperature maintenance temperature Tjmin. Then, as shown in FIG. 7, it is determined as NO in the above step (S222) until the time T4 when the semiconductor junction temperature Tj becomes the low temperature side maintenance temperature Tjmin (that is, the monitor temperature Tmon becomes the low temperature side maintenance temperature Tmin). The Therefore, the process (S222) is repeated until the time point T4 is reached.

  Then, at time T4 shown in FIG. 7, when the semiconductor junction temperature Tj reaches the low temperature side maintenance temperature Tjmin, YES is determined in the step (S222). As a result, a step (S223) of starting PWM control of the Peltier drive power supply is performed. When this step (S223) is carried out, as shown in FIG. 7, the Peltier drive power supply repeats ON / OFF again at a predetermined interval. Specifically, as shown in FIG. 7, ON / OFF of the Peltier drive power supply is repeated at a predetermined interval, whereby the output of the Peltier drive power supply has a pulse waveform. The amount of heat Qr transmitted from the base plate 5 side to the radiator 11 side in the Peltier element 9 is controlled by appropriately controlling the width and interval of the pulse wave. As a result, the calorific value Qgen from the measured object 1 and the heat quantity Qr transmitted from the measured object 1 to the radiator 11 through the base plate 5 and the Peltier element 9 and removed by the refrigerant 17 have a predetermined balance. . Therefore, as shown in FIG. 7, the monitor temperature Tmon and the semiconductor junction temperature Tj can be maintained at the low temperature side maintenance temperatures Tmin and Tjmin, respectively.

  Then, the state in which the monitor temperature Tmon and the semiconductor junction temperature Tj as described above are maintained constant starts at time T4 in FIG. 7 and continues for a predetermined time. At this time, in the control flow shown in FIG. 6, whether a predetermined time has elapsed since the semiconductor junction temperature Tj became Tjmin in the step (S224) (whether the time from time T4 to time T5 has elapsed). To be judged. Until the time T5 in FIG. 7 is NO in the step (S224), the step (S224) is repeated until the time T5. For this reason, the PWM control of the Peltier drive power supply is continued until time point T5, whereby the monitor temperature Tmon and the semiconductor junction temperature Tj are maintained at the low temperature side maintenance temperatures Tmin and Tjmin, respectively.

  And when it becomes time T5, it will be judged as YES in a process (S224). As a result, the step (S230) shown in FIG. 6 is performed. In step (S230), it is determined whether the temperature raising step (step (S211) to step (S214)) and the cooling step (step (S221) to step (S224)) have been repeated a predetermined number of times.

  When it is determined NO in the step (S230), the steps after the step (S211) are sequentially repeated again. That is, the temperature raising process is started again from time T5 in FIG. The control started from time T5 is just the same as the control started from time T1. That is, at the time T5, the process (S211) of FIG. 6 is performed. From this time T5, as shown in FIG. 7, the monitor temperature Tmon and the semiconductor junction temperature Tj start to rise. Then, the process (S212) is repeated until time T6. Further, at time T6, as in the case of time T2, the semiconductor junction temperature Tj reaches Tjmax, which is the high temperature side maintenance temperature, and the monitor temperature Tmon reaches Tmax, which is the high temperature side maintenance temperature. Then, at time T6, as in the case of time T2, it is determined YES in step (S212), and each step after step (S215) is sequentially performed.

  Further, if it is determined YES in the step (S230), that is, if it is determined that the temperature raising step and the cooling step are repeated a predetermined number of times, the thermal cycle test is ended, so that Peltier driving as post-processing is performed. A step of turning off the power (S241) is performed. In this way, the test process (S200) in case 2 is performed.

(Case 3)
In order to control the heat generation amount (Qgen) from the device under test 1, the voltage change control is applied to the power supply 22 for the device under test heat generation, and the voltage change control is also applied to the power source 23 for the Peltier element. In this case, the amount of heat (Qr) removed from the DUT 1 via the Peltier element 9 and the radiator 11 is controlled. A specific control flow is shown in FIG. 8, and a timing chart showing changes in power ON / OFF, changes in voltage conditions, and changes in temperature conditions is shown in FIG. FIG. 8 is a flowchart showing a test process in an example of a device evaluation method according to the present invention. FIG. 9 is a timing chart showing changes in power ON / OFF, voltage conditions, and temperature conditions in the test process according to the flowchart shown in FIG. In FIG. 9, the horizontal axis indicates time, and the vertical axis indicates five characteristic values. That is, the vertical axis in FIG. 9 shows the change in the semiconductor junction temperature Tj in the semiconductor device from the top, the change in the temperature of the device under test 1 (monitor temperature Tmon) measured by the thermocouple 7 in FIG. 23 shows ON / OFF of 23 (Peltier drive power supply), ON / OFF of the measured object heating power supply 22 (semiconductor drive power supply), and changes in voltage levels of the semiconductor drive power supply and the Peltier drive power supply. With reference to FIG. 8 and FIG. 9, the test process in an example (case 3) of the device evaluation method by this invention is demonstrated.

  Referring to FIGS. 8 and 9, in the test process, first, as part of the temperature raising process (S210) (see FIG. 3), the semiconductor drive power supply is turned on and the Peltier drive power supply is turned off (S218). To implement. This step (S218) is performed at time T1 in the timing chart of FIG. At this time, the voltage setting value of the semiconductor driving power source is set to the maximum value (Vmax), and the voltage setting value of the Peltier driving power source is set to the minimum value (Vmin). From this time T1, the monitor temperature Tmon and the semiconductor junction temperature Tj start to rise as shown in FIG. During the test step (S200), the power to be measured 1 is supplied from the power supply for measured object 21 (see FIG. 1) to the measured object 1.

  In step (S216) of FIG. 8, the voltage setting value of the semiconductor drive power supply is changed from Vmax to Vmin. Specifically, a step of determining whether or not a predetermined time from a time T1 to a specific time has elapsed from the time T1 is performed, and when it is determined that the predetermined time has elapsed from the time T1 in the step Then, a step of reducing the voltage set value from Vmax is started. Then, similarly to the step (S212) of FIG. 4, it is determined whether or not the semiconductor junction temperature Tj has reached Tjmax, which is the high temperature side maintenance temperature. In the same step as this step (S212), NO is determined until time T2 in FIG. 9, and therefore, this step is repeated until time T2 in FIG.

  At time T2 in FIG. 9, the semiconductor junction temperature Tj reaches Tjmax, which is the high-temperature side maintenance temperature, and the monitor temperature Tmon reaches Tmax, which is the high-temperature side maintenance temperature. The semiconductor junction temperature Tj is obtained from the monitor temperature Tmon by calculation.

  Thus, when the semiconductor junction temperature Tj reaches Tjmax at time T2, YES is determined in the above-described step similar to the step (S212), and the decrease in the voltage setting of the semiconductor drive power supply is stopped. The voltage setting value of the semiconductor drive power supply at this time becomes the lower limit value (Vmin) of the voltage setting. Thereafter, the voltage setting value of the semiconductor drive power supply is maintained at Vmin. In this way, by changing the voltage setting value of the semiconductor drive power supply, the heat generation amount Qgen from the measured object 1 is transmitted to the radiator 11 from the measured object 1 via the base plate 5 and the Peltier element 9, and the refrigerant The amount of heat Qr removed by 17 has a predetermined balance. Therefore, as shown in FIG. 9, the monitor temperature Tmon and the semiconductor junction temperature Tj can be maintained at the maintenance temperatures Tmax and Tjmax on the high temperature side, respectively.

  Next, in step (S217), the voltage setting value of the Peltier drive power supply is changed from Vmin to the maximum value (Vmax). Specifically, the process of determining whether or not a predetermined time has elapsed from time T2 shown in FIG. 9 (whether or not time T3 has been reached) is performed, and it is determined that time T3 has been reached in the process. Then, a step of increasing the voltage setting value of the Peltier drive power supply from Vmin and changing it to the maximum value (Vmax) is started. After this process is started, the voltage setting value of the Peltier drive power supply is changed to the maximum value (Vmax) after a very short time has elapsed.

  Then, the state in which the monitor temperature Tmon and the semiconductor junction temperature Tj as described above are maintained constant starts at time T2 in FIG. 9 and continues for a predetermined time. At this time, in the control flow shown in FIG. 8, whether a predetermined time has elapsed since the semiconductor junction temperature Tj became Tjmax in the step (S214) (whether the time from time T2 to time T4 has elapsed). To be judged. Until time T4 in FIG. 9 is NO in step (S214), step (S214) is repeated until time T4. For this reason, the ON state of the semiconductor drive power supply is continued until time T4. Further, since the voltage setting value of the semiconductor drive power supply is maintained at the minimum value (Vmin) from the time point T2, as described above, the heat generation amount (Qgen) from the measured object and the heat dissipation amount via the Peltier element 9 ( Since Qr) is balanced, the monitor temperature Tmon and the semiconductor junction temperature Tj are maintained at the high temperature side maintenance temperatures Tmax and Tjmax, respectively.

  When time T4 is reached, YES is determined in the step (S214), and the cooling step (S220) in FIG. 3 is started. Specifically, a process (S221) of turning off the semiconductor drive power and turning on the Peltier drive power is performed at time T4 in FIG. As a result, as shown in FIG. 9, the monitor temperature Tmon and the semiconductor junction temperature Tj start to decrease from time T4.

  Thereafter, in the flowchart shown in FIG. 8, it is determined in step (S222) whether or not the semiconductor junction temperature Tj has become the low temperature side maintenance temperature Tjmin. Then, as shown in FIG. 9, it is determined NO in the step (S222) until time T5 when the semiconductor junction temperature Tj becomes the low temperature side maintenance temperature Tjmin (that is, the monitor temperature Tmon becomes the low temperature side maintenance temperature Tmin). The Therefore, the process (S222) is repeated until the time point T5 is reached.

  Then, when the time T5 shown in FIG. 9 is reached and the semiconductor junction temperature Tj becomes the maintenance temperature Tjmin on the low temperature side, YES is determined in the step (S222). As a result, the step (S225) is performed. In step (S225), the voltage setting value of the Peltier driving power supply is changed from Vmax to Vmin, and the voltage setting value of the semiconductor driving power supply is changed from Vmin to Vmax. Note that the timing for starting the change of the voltage setting value of the Peltier drive power supply from Vmax to Vmin may be before time T5. Specifically, a step of determining whether or not a predetermined time has elapsed from time T4 is performed, and when the predetermined time has elapsed in the step, the change of the voltage setting value of the Peltier drive power supply from Vmax to Vmin is started. Also good. Then, by changing the voltage setting value of the Peltier drive power source to Vmin, the amount of heat Qr transmitted from the base plate 5 side to the radiator 11 side in the Peltier element 9 is controlled. As a result, the calorific value Qgen from the measured object 1 and the heat quantity Qr transmitted from the measured object 1 to the radiator 11 through the base plate 5 and the Peltier element 9 and removed by the refrigerant 17 have a predetermined balance. . Therefore, as shown in FIG. 9, the monitor temperature Tmon and the semiconductor junction temperature Tj can be maintained at the low temperature side maintenance temperatures Tmin and Tjmin, respectively.

  Then, the state in which the monitor temperature Tmon and the semiconductor junction temperature Tj as described above are maintained constant starts at time T5 in FIG. 5 and continues for a predetermined time. At this time, in the control flow shown in FIG. 8, whether a predetermined time has passed since the semiconductor junction temperature Tj became Tjmin in the step (S224) (whether the time from time T5 to time T6 has passed). To be judged. Until time T6 in FIG. 9 is NO in step (S224), step (S224) is repeated until time T6. For this reason, the control of turning off the semiconductor drive power supply while the Peltier drive power supply is turned on while the voltage setting value of the Peltier drive power supply is set to Vmin until time T6, the monitor temperature Tmon and the semiconductor junction temperature are maintained. Tj is maintained at maintenance temperatures Tmin and Tjmin on the low temperature side, respectively.

  And when it becomes time T6, it will be judged as YES in a process (S224). As a result, the step (S230) shown in FIG. 8 is performed. In step (S230), it is determined whether the temperature increasing step (step (S218) to step (S214) in FIG. 8) and the cooling step (step (S221) to step (S224) in FIG. 8) have been repeated a predetermined number of times. When it is determined NO in the step (S230), the steps after the step (S218) are sequentially repeated again.

  That is, the temperature raising process is started again from time T6 in FIG. The control started from time T6 is just the same as the control started from time T1. That is, at time T6, the step of turning on the semiconductor drive power and turning off the Peltier drive power (S218) is performed. At this time, the voltage setting value of the semiconductor driving power source is set to the maximum value (Vmax), and the voltage setting value of the Peltier driving power source is set to the minimum value (Vmin). From this time T6, as shown in FIG. 9, the monitor temperature Tmon and the semiconductor junction temperature Tj start to rise. Then, at time T7 in FIG. 9, the step (S216) in FIG. 8 is performed. Specifically, a step of changing the voltage setting value of the semiconductor drive power supply from Vmax to Vmin is started. At time T8 in FIG. 9, the semiconductor junction temperature Tj reaches Tjmax, which is the high temperature side maintenance temperature, and the monitor temperature Tmon reaches Tmax, which is the high temperature side maintenance temperature.

  Further, if it is determined YES in the step (S230), that is, if it is determined that the temperature raising step and the cooling step are repeated a predetermined number of times, the thermal cycle test is ended, so that Peltier driving as post-processing is performed. A step of turning off the power (S241) is performed. In this way, the test process (S200) in case 3 is performed.

(Case 4)
In order to control the heat generation amount (Qgen) from the device under test 1, ON / OFF control is performed on the power source 22 for the device under test heat generation, while voltage change control is applied to the power source 23 for Peltier elements to This is a case where the amount of heat (Qr) removed from the DUT 1 via the element 9 and the radiator 11 is controlled. A specific control flow is shown in FIG. 10, and a timing chart showing changes in power ON / OFF, changes in voltage conditions, changes in temperature conditions, and the like is shown in FIG. FIG. 10 is a flowchart showing a test process in an example of a device evaluation method according to the present invention. FIG. 11 is a timing chart showing changes in power ON / OFF, voltage conditions, and temperature conditions in the test process according to the flowchart shown in FIG. FIG. 11 is basically shown in the same manner as FIG. 9, where the horizontal axis indicates time, and the vertical axis indicates five characteristic values. That is, the vertical axis in FIG. 11 shows the change in the semiconductor junction temperature Tj in the semiconductor device from the top, the change in the temperature of the measurement target 1 (monitor temperature Tmon) measured by the thermocouple 7 in FIG. 23 shows ON / OFF of 23 (Peltier drive power supply), ON / OFF of the measured object heating power supply 22 (semiconductor drive power supply), and changes in voltage levels of the semiconductor drive power supply and the Peltier drive power supply. With reference to FIG. 10 and FIG. 11, the test process in an example (case 4) of the device evaluation method by this invention is demonstrated.

  Referring to FIGS. 10 and 11, in the test process, first, as part of the temperature raising process (S210) (see FIG. 3), the semiconductor drive power is turned on, as in the flowchart shown in FIG. A step (S218) of turning off the Peltier drive power is performed. This step (S218) is performed at time T1 in the timing chart of FIG. At this time, the voltage setting value of the semiconductor driving power source is set to the maximum value (Vmax), and the voltage setting value of the Peltier driving power source is set to the minimum value (Vmin). From this time T1, as shown in FIG. 11, the monitor temperature Tmon and the semiconductor junction temperature Tj start to rise. In the case 2, as in the case 1 described above, during the test step (S200), the device under test 1 is required for normal operation from the device under test power supply 21 (see FIG. 1). Power is supplied.

  Then, in step (S212) of FIG. 10, it is determined whether or not the semiconductor junction temperature Tj has reached Tjmax, which is the maintenance temperature on the high temperature side. In this step (S212), NO is determined from the time point T1 to the time point T2 in FIG. 11, so the step (S212) is repeated until the time point T2 in FIG.

  At time T2 in FIG. 11, the semiconductor junction temperature Tj reaches Tjmax, which is the high temperature side maintenance temperature, and the monitor temperature Tmon reaches Tmax, which is the high temperature side maintenance temperature. As described above, when the semiconductor junction temperature Tj reaches Tjmax at time T2, YES is determined in step (S212), and the next step (S219) is performed. In this step (S219), ON / OFF switching control of the Peltier drive power supply is performed. Specifically, as shown in FIG. 11, the Peltier drive power supply is switched from OFF to ON. For this reason, a predetermined amount of heat Qr is removed from the measured object 1 by the refrigerant 17 through the base plate 5, the Peltier element 9, and the radiator 11. On the other hand, the measured object 1 continues to generate heat of a predetermined heat generation amount Qgen by the power supplied from the semiconductor drive power supply. As a result, the calorific value Qgen from the measured object 1 and the heat quantity Qr transmitted from the measured object 1 to the radiator 11 through the base plate 5 and the Peltier element 9 and removed by the refrigerant 17 have a predetermined balance. . Therefore, as shown in FIG. 11, the monitor temperature Tmon and the semiconductor junction temperature Tj can be maintained at the high temperature side maintenance temperatures Tmax and Tjmax, respectively.

  Then, the state in which the monitor temperature Tmon and the semiconductor junction temperature Tj as described above are maintained constant starts at time T2 in FIG. 11 and continues for a predetermined time. At this time, in the control flow shown in FIG. 10, whether a predetermined time has elapsed since the semiconductor junction temperature Tj became Tjmax in the step (S214) (whether the time from time T2 to time T3 has elapsed). To be judged. Until time T3 in FIG. 11 is NO in step (S214), step (S214) is repeated until time T3. For this reason, the state in which the heat quantity Qr and the heat quantity Qgen described above are balanced until time T3 continues, so that the monitor temperature Tmon and the semiconductor junction temperature Tj are maintained at the high temperature side maintenance temperatures Tmax and Tjmax, respectively.

  When time T3 is reached, YES is determined in step (S214), and therefore the cooling step (S220) in FIG. 3 is started. Specifically, at time T3 in FIG. 11, a step of turning off the semiconductor drive power and changing the voltage setting value of the Peltier drive power from Vmin to Vmax (S226) is performed. As a result, as shown in FIG. 11, the monitor temperature Tmon and the semiconductor junction temperature Tj start to decrease from time T3. In the step (S226), the Peltier drive power supply is maintained in the ON state.

  Thereafter, in the flowchart shown in FIG. 10, it is determined in step (S222) whether or not the semiconductor junction temperature Tj has become the low-temperature maintenance temperature Tjmin. Then, as shown in FIG. 11, it is determined as NO in the above step (S222) until the time T4 when the semiconductor junction temperature Tj becomes the low temperature side maintenance temperature Tjmin (that is, the monitor temperature Tmon becomes the low temperature side maintenance temperature Tmin). The Therefore, the process (S222) is repeated until the time point T4 is reached.

  Then, at time T4 shown in FIG. 11, when the semiconductor junction temperature Tj becomes the low temperature side maintenance temperature Tjmin, YES is determined in the step (S222). As a result, step (S227) is performed. In step (S227), the voltage setting value of the Peltier drive power supply is changed from Vmax to Vmin. Note that the timing for starting the change of the voltage setting value of the Peltier drive power supply from Vmax to Vmin may be before time T4. Specifically, a step of determining whether or not a predetermined time has elapsed from time T3 is performed, and when the predetermined time has elapsed in the step, a change in the voltage setting value of the Peltier drive power supply from Vmax to Vmin is started. Also good. Then, when the voltage setting value of the Peltier drive power supply is changed to Vmin, the amount of heat Qr transmitted from the base plate 5 side to the radiator 11 side in the Peltier element 9 is controlled to be small. As a result, the calorific value Qgen from the measured object 1 and the heat quantity Qr transmitted from the measured object 1 to the radiator 11 through the base plate 5 and the Peltier element 9 and removed by the refrigerant 17 have a predetermined balance. . Therefore, as shown in FIG. 11, the monitor temperature Tmon and the semiconductor junction temperature Tj can be maintained at the low temperature side maintenance temperatures Tmin and Tjmin, respectively.

  Then, the state in which the monitor temperature Tmon and the semiconductor junction temperature Tj as described above are maintained constant starts at time T4 in FIG. 11 and continues for a predetermined time. At this time, in the control flow shown in FIG. 10, whether a predetermined time has elapsed since the semiconductor junction temperature Tj became Tjmin in the step (S224) (whether the time from time T4 to time T5 has elapsed). To be judged. Until time T5 in FIG. 11 is NO in step (S224), step (S224) is repeated until time T5. For this reason, the control of turning off the semiconductor drive power supply while the Peltier drive power supply is turned on while the voltage setting value of the Peltier drive power supply is set to Vmin until time T6, the monitor temperature Tmon and the semiconductor junction temperature are maintained. Tj is maintained at maintenance temperatures Tmin and Tjmin on the low temperature side, respectively.

  And when it becomes time T5, it will be judged as YES in a process (S224). As a result, the step (S230) shown in FIG. 10 is performed. In step (S230), it is determined whether the temperature raising step (step (S218) to step (S214)) and the cooling step (step (S226) to step (S224)) are repeated a predetermined number of times.

  When it is determined NO in the step (S230), the steps after the step (S218) are sequentially repeated again. That is, the temperature raising process is started again from time T5 in FIG. The control started from time T5 is just the same as the control started from time T1. That is, at the time T5, the step (S218) of FIG. 10 is performed. From this time T5, as shown in FIG. 11, the monitor temperature Tmon and the semiconductor junction temperature Tj start to rise. Then, the process (S212) is repeated until time T6. Further, at time T6, as in the case of time T2, the semiconductor junction temperature Tj reaches Tjmax, which is the high temperature side maintenance temperature, and the monitor temperature Tmon reaches Tmax, which is the high temperature side maintenance temperature. Then, YES is determined in step (S212) at time T6 as in the case of time T2, and each step after step (S219) is sequentially performed.

  Further, if it is determined YES in the step (S230), that is, if it is determined that the temperature raising step and the cooling step are repeated a predetermined number of times, the thermal cycle test is ended, so that Peltier driving as post-processing is performed. A step of turning off the power (S241) is performed. In this way, the test process (S200) in case 4 is performed.

(Embodiment 2)
FIG. 12 is a schematic diagram of Embodiment 2 of the evaluation apparatus according to the present invention. With reference to FIG. 12, Embodiment 2 of the evaluation apparatus according to the present invention will be described.

  As shown in FIG. 12, the evaluation apparatus 30 as the second embodiment of the device evaluation apparatus according to the present invention basically has the same configuration as the evaluation apparatus 30 shown in FIG. It differs in that it does not have.

  That is, in the evaluation apparatus 30 shown in FIG. 12, the measured object 1 is directly connected to the upper surface of the Peltier element 9 via the grease 3. A recess for arranging the thermocouple 7 is formed on the upper surface of the Peltier element 9. A thermocouple 7 for measuring the temperature of the measurement object 1 is disposed inside the recess.

  Even with such a configuration, basically the same effects as those of the evaluation apparatus 30 shown in FIG. 1 can be obtained. In the configuration shown in FIG. 12, the base plate 5 (see FIG. 1) is omitted, and the upper part of the Peltier element 9 is used as a base plate. In such a configuration, there is no significant difference between the area of the upper surface of the Peltier element 9 and the area occupied by the measured object 1 (the area of the measured object 1 that faces the upper surface of the Peltier element 9 via the grease 3). In such a case, the configuration of the evaluation device 30 can be simplified without significantly degrading the conditions for heat transfer from the DUT 1 to the Peltier element 9, which is particularly effective. In addition, in the evaluation apparatus 30 shown in FIG. 12, although the fixing member 20 is arrange | positioned, it is good also as a structure which does not use this fixing member 20. FIG.

  Next, although there are some overlapping with the above-described embodiment, a configuration example of the present invention will be listed and described.

  An evaluation apparatus 30 as a device evaluation apparatus according to the present invention includes an electronic cooling element (Peltier element 9), a heat radiating member (heat radiator 11, refrigerant flow path 13, heat exchanger 15, pump 14, refrigerant 17) and control unit. (Control device 29). The electronic cooling element (Peltier element 9) is thermally connected to the measurement object 1 including a semiconductor device. The heat radiating member (heat radiator 11, refrigerant flow path 13, heat exchanger 15, and pump 14) is thermally connected to the electronic cooling element (Peltier element 9). The control unit (control device 29) controls the power input to the device under test 1 and the electronic cooling element (Peltier element 9).

  In this way, by inputting electric power to the device under test 1 itself, the device under test 1 itself can generate heat, and the temperature of the device under test 1 including the semiconductor device can be raised, so that the device under test can be measured from the outside. The thermal cycle test can be performed under conditions closer to the actual operation conditions of the body 1 to be measured than when the body 1 is heated. Therefore, even when the semiconductor device of the device under test 1 operates in a higher temperature range than a device using conventional silicon like a device using SiC, the operating temperature range of the device under test 1 (higher temperature range than before) ) Can be easily performed.

  Further, since the device under test 1 itself is used as a heating element, it is not necessary to arrange a heating device such as a heater in the evaluation device 30 itself. For this reason, the apparatus structure of the evaluation apparatus 30 can be simplified.

  As shown in FIG. 1 and the like, the evaluation apparatus 30 further includes a sealed case 28 capable of isolating the measured object 1 thermally connected to the electronic cooling element (Peltier element 9) from at least the outside air. May be. In this case, by appropriately adjusting the composition of the atmospheric gas inside the sealed case 28, it is possible to prevent dew condensation from occurring on the surface of the measured object 1 as the temperature of the measured object 1 rises and falls. . As a result, it is possible to prevent a problem such as a failure from occurring in the measurement object 1 due to the condensation.

  Further, in the evaluation apparatus 30, the sealed case 28 includes the measured object 1, the electronic cooling element (Peltier element 9), and a part of the heat radiating member (connection portion of the heat radiator 11 and the refrigerant flow path 13 to the heat radiator 11). You may form so that it may surround. In this case, by appropriately adjusting the composition of the atmospheric gas inside the sealed case 28, the surface of the measured object 1, the electronic cooling element (Peltier element 9), the heat radiating member (heat radiator 11 or refrigerant flow path 13), etc. Condensation can be prevented from occurring. For this reason, a failure occurs in the electronic cooling element, the heat radiating member, etc. due to the condensation, or the electronic cooling element (Peltier element 9) cannot be operated normally, and as a result, the test cannot be performed normally. Can be prevented.

  The evaluation device 30 may further include a temperature sensor (thermocouple 7) that measures the temperature of the DUT 1. In this case, since the temperature of the measurement object 1 can be measured by the temperature sensor (thermocouple 7), it is possible to accurately monitor whether the temperature change of the measurement object 1 matches the temperature change planned in the test. it can. Moreover, since the temperature of the measurement object 1 can be accurately measured by the temperature sensor (thermocouple 7), the temperature data can be fed back to the control of the evaluation device 30. As a result, accurate temperature control can be performed in the evaluation device 30.

  The evaluation device 30 may further include a current sensor for a measured object (current sensor 25 connected to the power supply for measured object 21) that measures a current supplied to the measured object 1. In this case, by measuring the value of the current supplied to the device under test 1, it is possible to quickly detect an abnormality in the evaluation device 30 or the device under test 1 that affects the value of the current.

  For example, in the current sensor 25, a Hall element or a current transformer can be used as a current detection sensor. When the current sensor 25 detects a current value higher than a predetermined current value (when an overcurrent is detected), the controller 26 cuts off the supply of power to the device under test 1. At the same time, the test is stopped by the controller 26 and an abnormality of the evaluation device 30 is notified to the user. As the notification means, for example, a display device such as an LCD or a CRT installed in the evaluation device 30 may display that the value of the current supplied to the measured object 1 has become excessive, or / and simultaneously a speaker. An alarm sound may be generated from the above.

  Further, when a current value lower than a predetermined current value is detected in the current sensor 25 (when an undercurrent is detected), similarly to the above-described case, the controller 26 supplies power to the DUT 1. Shut off the supply. At the same time, the test is stopped by the controller 26 and an abnormality of the evaluation device 30 is notified to the user. As the notification means, a display device or a speaker as described above may be used.

  The evaluation apparatus 30 may further include an electronic cooling element current sensor (current sensor 25 connected to the Peltier element power supply 23) for measuring a current supplied to the electronic cooling element (Peltier element 9). In this case, when a change occurs in the value of the current supplied to the electronic cooling element due to the failure of the electronic cooling element (Peltier element 9), the abnormality of the evaluation apparatus 30 due to the failure of the electronic cooling element is quickly detected. Can be detected.

  As a current detection sensor used in the current sensor 25, for example, a Hall element or a shunt resistor can be used. When the current sensor 25 detects a current value higher than a predetermined current value (when an overcurrent is detected), the controller 26 supplies power to the Peltier element 9 and the DUT 1. Shut off. At the same time, the test is stopped by the controller 26 and an abnormality of the evaluation device 30 is notified to the user.

  Also, when a current value lower than a predetermined current value is detected by the current sensor 25 (when an undercurrent is detected), the Peltier element 9 and the DUT 1 are measured by the controller 26 as in the above case. Shut off the power supply to At the same time, the test is stopped by the controller 26 and an abnormality of the evaluation device 30 is notified to the user. As the notification means, a display device or a speaker as described above may be used.

  In the evaluation apparatus 30, the heat radiating member includes a base member (heat radiator 11) connected to the electronic cooling element (Peltier element 9) and a refrigerant 17 for removing heat from the base member (heat radiator 11). You may go out. The evaluation device 30 may further include a refrigerant temperature sensor (the temperature sensor 16 installed in the refrigerant flow path 13) for measuring the temperature of the refrigerant 17. In this case, since the temperature of the refrigerant 17 can be monitored by the refrigerant temperature sensor 16, the cooling efficiency decreases due to an abnormality occurring in the heat radiating member (for example, the refrigerant amount decreases due to the leakage of the refrigerant 17 from the refrigerant flow path 13 or the like). Etc.) can be detected quickly.

  In addition, a thermocouple etc. can be used as the temperature sensor 16 mentioned above. When the temperature sensor 16 detects a temperature higher than the set temperature, the controller 26 cuts off the supply of power to the DUT 1 and the Peltier element 9. At the same time, the test is stopped by the controller 26 and an abnormality of the evaluation device 30 is notified to the user. As the notification means, a display device or a speaker as described above may be used.

  In the evaluation apparatus 30, the measured object power supply 21, the measured object heating power supply 22, the Peltier element power supply 23, and the cooling system power supply 24 are provided to protect the apparatus from an excessive load on these power supplies. It is preferable to set a fuse in the above. As a result, it is possible to prevent the evaluation apparatus 30 from being damaged due to overcurrent or the like.

  In the evaluation device 30, the control unit (the control device 29) may be capable of controlling the power input to the device under test 1 by PWM control or voltage change control. In this case, it is possible to finely control the amount of heat generated from the measurement object 1. Therefore, the temperature of the device under test 1 can be maintained with high accuracy in a relatively high temperature state or a relatively low temperature state and a constant temperature state.

  In the evaluation device 30, the control unit (control device 29) may be capable of controlling the power input to the electronic cooling element (Peltier element 9) by PWM control or voltage change control. In this case, the cooling capacity of the electronic cooling element (Peltier element 9) can be finely controlled. Therefore, temperature control of the DUT 1 can be performed with high accuracy.

  The evaluation apparatus 30 may further include a fixing member (the flange portion 10 and the fixing screw 12) for connecting and fixing the electronic cooling element (Peltier element 9) to the heat radiating member (the upper surface of the radiator 11). In this case, the electronic cooling element (Peltier element 9) can be reliably connected and fixed to the heat radiating member (heat radiator 11) by the fixing members (flange portion 10 and fixing screw 12).

  In the evaluation apparatus 30, a plurality of objects to be measured 1 may be in a state of being thermally connected to the electronic cooling element (Peltier element 9). In this case, an evaluation test (thermal cycle test) can be performed on a plurality of measured objects 1 simultaneously. For example, in the evaluation apparatus 30 shown in FIG. 1, a plurality of measured objects 1 may be arranged side by side on the upper surface of the base plate 5. In this case, it is preferable that grooves (concave portions) are formed on the upper surface of the base plate 5 at positions facing the lower surfaces of the measured objects 1, and thermocouples are respectively disposed in the grooves. In the case of the evaluation apparatus 30 as shown in FIG. 12, a plurality of measured objects 1 may be arranged side by side on the upper surface of the Peltier element 9. In this case, it is preferable that grooves (concave portions) are formed on the upper surface of the Peltier element 9 at positions facing the lower surfaces of the measured objects 1 and thermocouples are respectively disposed in the grooves. In this way, an evaluation test can be performed while accurately measuring the temperature of each measured object 1.

  In the evaluation apparatus 30, the device under test 1 may be connected to an electronic cooling element (Peltier element 9) via a base plate 5 as shown in FIG. The planar shape of the base plate 5 may be larger than the planar shape of the DUT 1. In this case, the heat generated from the measurement object 1 can be transmitted to the electronic cooling element (Peltier element 9) after being diffused to some extent by the base plate 5. Therefore, in the case where the cooling capacity per unit area is not so large in the electronic cooling element (Peltier element 9), the area for transferring heat is increased by the base plate 5 and then the electronic cooling element (Peltier element) connected to the base plate 5 is increased. Enough cooling capacity can be ensured by increasing the area of the endothermic surface of the element 9).

  The device evaluation method according to the present invention is a device evaluation method using the evaluation apparatus 30, and as shown in FIG. 2, the device under test 1 is thermally connected to an electronic cooling element (Peltier element 9). A process (measurement object preparation process (S100)) and a test process (S200) are provided. In the test step (S200), by inputting electric power to the device under test 1, a heating step (temperature raising step (S210)) for raising the temperature of the device under test 1 and electric power for the electronic cooling element (Peltier device 9). Is input to the heat radiating member (the heat radiator 11 and the refrigerant 17) and the cooling step (S220) for cooling the device under test 1 is repeated one or more times. Control is performed by the control unit (control device 29).

  If it does in this way, while raising the temperature of to-be-measured body 1 using the heat_generation | fever from to-be-measured body 1 itself, the heat | fever of to-be-measured body 1 will be transmitted to a thermal radiation member by an electronic cooling element (Peltier element 9). By doing, the thermal cycle test with respect to the to-be-measured body 1 can be performed simply.

  In the device evaluation method, PWM control or voltage control may be used for power control. In this case, the amount of heat generated from the measured object 1 and the amount of heat absorbed by the electronic cooling element (Peltier element 9) (that is, the amount of heat transmitted to the heat radiating member) can be accurately controlled by PWM control or voltage control. Therefore, a constant temperature condition in the high temperature range and the low temperature range can be easily realized in the thermal cycle test.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The device evaluation apparatus and the device evaluation method according to the present invention perform a thermal cycle test of a device (for example, a device using SiC) that is used in a higher temperature range than a semiconductor device using a conventional silicon substrate. Is preferably used.

It is a schematic diagram of Embodiment 1 of the evaluation apparatus according to the present invention. It is a flowchart which shows the device evaluation method using the evaluation apparatus shown in FIG. It is a flowchart which shows the content of the test process in the flowchart shown in FIG. It is a flowchart which shows the test process in an example of the device evaluation method by this invention. FIG. 5 is a timing chart showing power ON / OFF and temperature condition transition in a test process according to the flowchart shown in FIG. 4. FIG. It is a flowchart which shows the test process in an example of the device evaluation method by this invention. 7 is a timing chart showing power ON / OFF and transition of temperature conditions in a test process according to the flowchart shown in FIG. 6. It is a flowchart which shows the test process in an example of the device evaluation method by this invention. FIG. 9 is a timing chart showing changes in power supply ON / OFF, voltage condition change, and temperature condition in a test process according to the flowchart shown in FIG. 8. It is a flowchart which shows the test process in an example of the device evaluation method by this invention. FIG. 11 is a timing chart showing changes in power ON / OFF, voltage conditions, and temperature conditions in the test process according to the flowchart shown in FIG. 10. It is a schematic diagram of Embodiment 2 of the evaluation apparatus according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Measured object, 3 Grease, 5 Base plate, 7 Thermocouple, 9 Peltier element, 10 Flange part, 11 Radiator, 12 Fixing screw, 13 Refrigerant flow path, 14 Pump, 15 Heat exchanger, 16 Temperature sensor, 17 Refrigerant, 18a, 18b Holding member, 19 Support member, 20 Fixing member, 21 Power supply for measured object, 22 Power supply for measured object heating, 23 Power supply for Peltier element, 24 Cooling system power supply, 25 Current sensor, 26 Controller, 28 Sealed case, 29 control device, 30 evaluation device.

Claims (10)

An electronic cooling element thermally connected to a measurement object including a semiconductor device;
A heat dissipating member thermally connected to the electronic cooling element;
A device evaluation apparatus comprising: the measurement object; and a control unit that controls electric power input to the electronic cooling element.   The device evaluation apparatus according to claim 1, further comprising a sealed case capable of isolating the measurement object thermally connected to the electronic cooling element from at least the outside air.   The device evaluation apparatus according to claim 1, further comprising a temperature sensor that measures a temperature of the measurement object.   The device evaluation apparatus according to claim 1, further comprising a current sensor for a measured object that measures a current supplied to the measured object.   The device evaluation apparatus according to claim 1, further comprising a current sensor for an electronic cooling element that measures a current supplied to the electronic cooling element. The heat radiating member includes a base member connected to the electronic cooling element, and a refrigerant for removing heat from the base member,
The device evaluation apparatus according to claim 1, further comprising a refrigerant temperature sensor for measuring a temperature of the refrigerant.   The device evaluation apparatus according to claim 1, wherein the control unit is capable of controlling electric power input to the measured object by PWM control or voltage change control.   The device evaluation apparatus according to claim 1, wherein the control unit is capable of controlling electric power input to the electronic cooling element by PWM control or voltage change control. A device evaluation method using the device evaluation apparatus according to any one of claims 1 to 8,
Thermally connecting the object to be measured to the electronic cooling element;
A heating step for increasing the temperature of the measurement object by inputting power to the measurement object, and a heat input to the electronic cooling element to transmit heat of the measurement object to a heat dissipation member, A device evaluation method comprising: a test step of controlling the power by a control unit so as to repeat the cooling step of cooling the measurement object one or more times.   The device evaluation method according to claim 9, wherein PWM control or voltage control is used for controlling the power.

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