JP2023014963A5 - - Google Patents

Description

The present invention relates to a power cycle test apparatus and a power cycle test method.

Patent Literature 1 describes a power cycle test apparatus that repeats a test cycle by applying and stopping power to a device under test and repeatedly applying temperature changes to the device under test. This power cycle test apparatus includes a power application section for applying power to the device under test, and a control section for controlling the power application by the power application section and stopping the power application.

Patent Document 2 describes a test burn-in device for middle power and high power ICs. This test burn-in equipment for middle power and high power ICs has a dehumidifying function to cool the device under test in the socket of the burn-in board, and to prevent condensation on the thermal head and thermal array for temperature control, the test socket, and the device under test. It has a closed structure.

Patent Literature 3 describes a temperature characteristic inspection apparatus capable of inspecting the operating characteristics of semiconductor devices at low temperatures in the state of chips. This temperature characteristic inspection apparatus includes an inspection table for carrying out an inspection with a light-emitting element or a light-receiving element chip for optical communication, a cooling mechanism for cooling the inspection table, and a cooling liquid for cooling the cooling mechanism. A cooling liquid supply/discharge mechanism consisting of a cooling liquid inlet pipe and a cooling liquid discharge pipe for discharging the cooling liquid that has cooled the cooling mechanism, and a cooling mechanism for the inspection table, the cooling mechanism, the cooling liquid inlet pipe, and the cooling liquid discharge pipe. A shielding plate that surrounds the following part, a dry air chamber that is fixed to the rear surface of the shielding plate and introduces dry air and temporarily stores it, and a dry air chamber that is located in front of the dry air chamber and supplies dry air to the inside of the shielding plate. A dry air supply plate that is a dry gas supply port, an opening that is a dry air discharge port that is cut from the front to the top of the shielding plate and is the entrance and exit of the semiconductor chip, and the semiconductor chip is carried to the inspection table through the opening for inspection. a carrying collet for carrying away from the table, a probe that passes through the opening and contacts the electrode of the semiconductor chip to apply a current or voltage, and a semiconductor chip that detects light emitted from the semiconductor chip through the opening to the outside or the semiconductor from the opening. and a device for detecting the optical properties of the semiconductor chip by illuminating the chip and detecting the photocurrent.

JP 2016-114403 A JP 2005-156172 A Japanese Patent Application Laid-Open No. 2007-163193

Here, when a power cycle test is performed while liquid-cooling a power module to be tested, dew condensation may occur on the test target depending on the test environment.
An object of the present invention is to provide a power cycle test apparatus and a power cycle test method that can suppress the occurrence of dew condensation.

The invention according to claim 1 includes a mounting table provided with a mounting area on which a power module attached to a liquid-cooled heat sink and having terminals is mounted,
a cover for covering the mounting table and forming a test space therein;
A power cycle testing device that energizes the power module and tests the power module,
a cable connection portion to which a cable extending to the terminal is connected;
a tube portion to which a tube for flowing cooling liquid is connected to the liquid-cooled heat sink;
a dry air supply pipe for supplying dry air maintained at a predetermined relative humidity or less;
a temperature and humidity measurement unit that measures the temperature and relative humidity inside the test space;
A control unit that controls the supply of the dry air,
The cable connection portion, the pipe portion, the dry air supply pipe and the temperature/humidity measurement portion are provided inside the test space,
In the power cycle test apparatus, the dry air is supplied until the dew point temperature obtained based on the temperature and the relative humidity measured by the temperature/humidity measuring unit becomes equal to or less than a predetermined set value.

The invention according to claim 2 is the power cycle test apparatus according to claim 1, wherein the first cable connection part and the second cable connection part are arranged in the left-right direction across the mounting area when viewed from the front. , and the cooling liquid supply pipe and the cooling liquid discharge pipe are arranged at positions on the rear end side of the upper surface of the mounting table.

The invention according to claim 3 is the power cycle test apparatus according to claim 2, wherein a liquid leakage suppressing member is provided so as to protrude from the upper surface of the mounting table for suppressing leakage of the cooling liquid to the outside, a liquid leakage sensor for detecting leaked cooling liquid, and a liquid drain hole for discharging the leaked cooling liquid is provided in the mounting table inside the liquid leakage suppressing member.

The invention according to claim 4 is the power cycle test apparatus according to claim 3, wherein the liquid leakage sensor has a detection band disposed inside the liquid leakage suppressing member, and the detection band is and is arranged to surround at least the mounting area and the coolant supply pipe.

According to a fifth aspect of the present invention , the power cycle test apparatus according to the fourth aspect further includes a bypass pipe connecting the coolant supply pipe and the coolant discharge pipe to each other.

The invention according to claim 6 is a power cycle test method using the power cycle test apparatus according to claim 1, wherein the power module with a liquid-cooled heat sink is mounted on the mounting area, and the control terminal and the power module are mounted on the mounting area. a preparatory step in which the first cable and the second cable are respectively connected between the first cable connection portion and between the main terminal and the second cable connection portion; and the preparatory step are performed. a test step in which the power module is energized in a predetermined cycle after the dew point temperature is determined; and a dew point temperature control step of supplying the dry air until the dry air becomes equal to or less than a set value.

According to a seventh aspect of the present invention, in the power cycle test method according to the sixth aspect, in the test step, the control unit controls the dew point temperature to be set in advance before the power module is energized. The dry air is supplied until the value is below the value.

ADVANTAGE OF THE INVENTION According to this invention, the power cycle test apparatus and power cycle test method which can suppress generation|occurrence|production of dew condensation can be provided.

1 is an external view of a power cycle test device according to an embodiment of the present invention; FIG. It is explanatory drawing of the power module with a liquid-cooled heat sink used as to-be-tested object of the same power cycle testing apparatus. (A) is a plan view of a mounting table provided in the same power cycle tester, and (B) is a cross-sectional view taken along the line XX shown in (A).

Next, specific embodiments of the present invention will be described with reference to the attached drawings for better understanding of the present invention. In addition, in the drawings, the illustration of parts that are not related to the description may be omitted.

A power cycle test apparatus 10 (see FIG. 1) according to one embodiment of the present invention can evaluate the reliability by energizing the power module PM in a preset cycle.
The power module PM is a thin-plate device, and incorporates, for example, upper and lower arms that constitute a part of the three-phase inverter circuit and sensors that detect the internal state. The power module PM has a plurality of control terminals (not shown) for inputting control signals and outputting sensor signals, and main terminals TM1 to TM3 (see FIG. 2) for inputting and outputting electric power, Each control terminal extends from a first end face, and main terminals TM1 to TM3 extend from a second end face opposite to the first end face.
However, the power module PM is not limited to such a configuration.

As shown in FIG. 2, the test object of the power cycle test apparatus 10 is a power module 14 with a liquid-cooled heat sink, which is composed of a plurality of power modules PM sandwiched between liquid-cooled heat sinks 12. As shown in FIG. The liquid-cooled heat sink 12 has a flow path (see arrows in FIG. 2) formed therein, and first tubes extending in one direction and spaced apart from each other on the upstream and downstream sides of the flow path. A connection 122a and a second tube connection 122b are provided. A first tube for supplying cooling liquid maintained at a predetermined temperature by a chiller (not shown) is connected to the first tube connection portion 122a, and a power module is connected to the second tube connection portion 122b. A second tube is connected for flowing coolant that has absorbed the heat generated by the PM.

The power cycle test apparatus 10, as shown in FIG. Can be tested simultaneously under various conditions.
The first test section 20a and the second test section 20b are arranged on the front side of the power cycle test apparatus 10, respectively. However, since the first test section 20a and the second test section 20b have substantially the same configuration, only the first test section 20a will be described below.

The first testing section 20 a has a mounting table 202 and a cover 204 .
The mounting table 202 has a rectangular parallelepiped outer shape, and the liquid-cooled power module 14 with a heat sink is mounted in a mounting area A (see FIG. 3A) provided in the center of the rectangular upper surface in the left-right direction. The held holder is placed.
A space is formed inside the mounting table 202 to accommodate pipes and cables.

As shown in FIG. 1, the cover 204 has a rectangular parallelepiped outer shape and can cover the upper surface of the mounting table 202 . The cover 204 can be opened and closed around a rotation axis AX extending in the left-right horizontal direction by means of a hinge 206 (see FIG. 3A) provided on the back side.
The cover 204 is supported by a gas spring (not shown) and is configured so that the tester can easily open and close it from the front side.
By covering the upper surface of the mounting table 202 with the cover 204, a test space S (see FIG. 1) indicated by broken lines is formed inside. A packing is provided on the contact surface of the cover 204 with the mounting table 202 to prevent air from leaking from the inside of the test space S to the outside. However, the test space S is not in a completely sealed state, but in an unsealed state.
The upper surface of the cover 204 is made of a transparent plate-like member, so that the test space S can be visually recognized from the outside.
Any cover 204 may be used as long as the test space S can be formed on the mounting table 202 .

As shown in FIGS. 3A and 3B, the test space S includes a first terminal block 210, a second terminal block 220, a coolant supply pipe 240, a coolant discharge pipe 230, a dry air A supply tube 250, a thermo-hygrometer 260 and an electromagnetic lock 270 are arranged.

A first terminal block (an example of a first cable connection portion) 210 is a terminal block to which a plurality of first cables (not shown) extending to control terminals of the power module PM are connected. It is fixed to the upper surface of the mounting table 202 via the . Wiring extending from the first terminal block 210 to the outside of the test space S is connected to a control unit (not shown) through a wiring hole H1 formed at a left rear end position on the upper surface of the mounting table 202. there is
A first connector (an example of a first cable connecting portion) may be used instead of the first terminal block 210, and any connecting portion for connecting the first cable may be used.

A plurality of second terminal blocks (an example of a second cable connecting portion) 220 are provided, and a plurality of second cables (unnecessary) extending to the corresponding main terminals TM1 to TM3 (see FIG. 2) of the power module PM are provided. shown in the figure) is a terminal block to which is connected. Each second terminal block 220 is fixed so as to pass through the upper surface of the mounting table 202, and a cable extending to the drive power supply unit 50 is connected inside the mounting table 202 (opposite side of the upper surface of the mounting table). It is
A second connector (an example of a second cable connecting portion) may be used instead of the second terminal block 220, and any connecting portion for connecting the second cable may be used.

The first terminal block 210 and the second terminal block 220 are arranged on the left and right sides of the upper surface of the mounting table 202 with the mounting area A interposed therebetween. Note that the first terminal block 210 and the second terminal block 220 are not limited to the arrangement shown in FIG. It suffices if they are arranged with a space in the left-right direction.

The coolant supply pipe 240 is connected to a first tube (not shown) extending to the first tube connection portion 122a of the liquid-cooled heat sink 12 to supply coolant cooled by a chiller (not shown). is a tube of The cooling liquid supply pipe 240 is arranged at a position on the rear end side (back side) of the upper surface of the mounting table 202 and extends upward.

The coolant discharge pipe 230 is connected to a second tube extending from the second tube connection portion 122b of the liquid-cooled heat sink 12, and is a pipe for returning the coolant that has cooled the power module PM to the chiller. The cooling liquid discharge pipe 230 is spaced apart from the cooling liquid supply pipe 240 and is arranged at a position on the rear end side (back side) of the upper surface of the mounting table 202 and extends upward.

A bypass pipe 280 that extends in the left-right direction and connects the coolant discharge pipe 230 and the coolant supply pipe 240 to each other is attached to the end of the coolant discharge pipe 230 and the end of the coolant supply pipe 240 . This bypass pipe 280 is provided with a valve 290 for opening and closing the flow path.
Therefore, the bypass pipe 280 can circulate the cooling liquid without attaching the test object, which facilitates inspection of the chiller (not shown) and the cooling liquid flow path.

The dry air supply pipe 250 is a pipe for supplying dry air maintained below a predetermined relative humidity. The dry air supply pipe 250 is arranged on the front end side of the upper surface of the mounting table 202 so as to protrude from the upper surface at a position closer to the front side than the mounting area A. is set to be higher than the height of
Therefore, the possibility that the coolant leaking for some reason enters the dry air supply pipe 250 is reduced.
Here, if the dry air directly hits the power module 14 with a liquid-cooled heat sink, it can be a factor affecting the internal temperature of the power module PM. In addition, if dry air hits the thermo-hygrometer 260 directly, it may cause an error in the measured value.
Therefore, it is preferable that the dry air is jetted upward. However, the blowing direction of the dry air may be any direction as long as it is different from the direction in which the power module 14 with liquid-cooled heat sink and the thermo-hygrometer 260 are located.

A thermo-hygrometer (an example of a temperature-humidity measuring unit) 260 is a sensor that measures the temperature and relative humidity inside the test space S. The thermo-hygrometer 260 is arranged on the right side of the upper surface of the mounting table 202 and on the rear end side. Therefore, since the thermo-hygrometer 260 is arranged at a position away from the dry air supply pipe 250 arranged on the front end side of the upper surface of the mounting table 202, errors in the measured values are suppressed.
Electromagnetic lock 270 can lock closed cover 204 from opening. The electromagnetic lock 270 is arranged on the upper surface of the mounting table 202 on the left front end side.

In the test space S, a leakage suppression member 310, a drainage hole H2, and a leakage sensor 320 are further arranged.
The liquid leakage suppression member 310 is a member that protrudes from the upper surface of the mounting table 202 and is provided to suppress leakage of the cooling liquid to the outside. The liquid leakage suppressing member 310 is arranged along the inner circumference of the lower end of the closed cover 204 to extend the first terminal block 210, the second terminal block 220, the cooling liquid supply pipe 240, the cooling liquid discharge pipe 230, and dry air. It is arranged so as to surround the supply pipe 250 , the thermo-hygrometer 260 and the electromagnetic lock 270 .

The drain hole H<b>2 is a hole for draining the leaked cooling liquid, and is formed at the rear end portion of the upper surface of the mounting table 202 . The liquid drain hole H2 is arranged inside the liquid leakage suppressing member 310, and is connected to a liquid drain pipe 315 (see FIG. 3B) for discharging the leaked cooling liquid.

The liquid leakage sensor 320 is a sensor for detecting leaked cooling liquid by, for example, an inter-electrode resistance detection method. The liquid leakage sensor 320 is arranged inside the liquid leakage suppressing member 310 and has an amplifier 322 and a band-shaped detection band 324 . A sensing band 324 is connected to an amplifier 322 via a connection terminal block 326 and terminated with a terminator 328 . The detection band 324 includes, in plan view, 1) a mounting area A on which the power module 14 with a liquid-cooled heat sink is mounted, 2) a drainage hole H2, 3) a coolant supply pipe 240, and 4) a dry air supply pipe 250. arranged to surround. However, the detection band 324 may be arranged so as to surround at least the placement area A and the coolant supply pipe 240 in plan view.

The drive power supply unit 50 is arranged behind the first test unit 20a and the second test unit 20b, and can supply power to each unit of the power cycle test apparatus 10 and the object to be tested. In addition, the driving power supply section 50 has a switching circuit using, for example, a power MOSFET, and can control the current for the power cycle test to be supplied to the power module PM.

A control unit (not shown) can control the chiller, thermo-hygrometer 260 , electromagnetic lock 270 , leakage sensor 320 and drive power supply unit 50 . Also, the controller can control the supply of dry air from the dry air supply pipe 250 .

Next, the operation of the power cycle test device 10 (power cycle test method using the power cycle test device 10) will be described.

(preparation step)
The tester opens the cover 204 upward and places the power module 14 with a liquid-cooled heat sink (see FIG. 2) to be tested held in a holder (not shown) on the placement area A. At this time, the test object is arranged so that the control terminals of the power module PM are on the first terminal block 210 side and the main terminals TM1 to TM3 are on the second terminal block side. Also, the test object is arranged so that the first tube connection portion 122a and the second tube connection portion 122b are on the back side or the top side.
After that, the tester connects the control terminal of each power module PM and the first terminal block 210 with the first cable, and connects the main terminals TM1 to TM3 and the second terminal block 220 with the second cable. to connect. Furthermore, the tester connects the first tube connection portion 122a of the liquid-cooled heat sink 12 and the coolant supply pipe 240 with the first tube, and connects the second tube connection portion 122b and the coolant discharge pipe 230. are connected with a second tube.

In this manner, the first terminal block 210 and the second terminal block 220 are arranged on the left and right sides of the mounting area A, respectively, and the cooling liquid supply pipe 240 and the cooling liquid Since the discharge pipe 230 is arranged, the tester can easily perform wiring and piping work from the front side of the mounting table 202 .
Therefore, the cover 204 that covers the mounting table 202 opens upward, and a wide space for the examiner to work is secured, thereby improving workability in preparing for the test.
After completing the wiring, etc., the tester closes the cover 204 and starts the operation of the chiller. The closed cover 204 is locked by an electromagnetic lock 270 . As the chiller operates, the temperature of the coolant drops. Depending on the test environment, condensation may occur on the power module 14 with a liquid-cooled heat sink.

(test step)
After the preparation steps are completed, the tester outputs a command signal from the operation panel (not shown) to the controller (not shown) to start the power cycle test.
When the power cycle test is started, the controller calculates the dew point temperature for each predetermined period ST, and supplies dry air from the dry air supply pipe 250 until all of the predetermined conditions A to C are satisfied.
Here, the condition A is that the dew point temperature obtained based on the temperature and relative humidity measured by the thermohygrometer 260 is equal to or less than a predetermined set value.
Condition B is that the coolant temperature has reached within a predetermined range.
Condition C is that a preset time T has passed since the power cycle test was started. This time T is set as the time required to dry the power module 14 with a liquid-cooled heat sink that has dew condensation.

The dew point temperature is calculated from the relative humidity inside the test space S measured by the thermo-hygrometer 260 by obtaining an approximate value of the saturated water vapor pressure from the temperature inside the test space S measured by the thermo-hygrometer 260. obtained from the water vapor pressure. The relationship between the saturated water vapor pressure and the temperature is determined, for example, by the Tetens equation.
When all of the predetermined conditions A to C are satisfied, the controller stops the supply of dry air and energizes the power module PM in a predetermined cycle.

(Dew point temperature control step)
While the power module PM is energized in a predetermined cycle, the controller continues to calculate the dew point temperature for each predetermined cycle ST and monitors whether the calculated dew point temperature is within a predetermined range.
The controller supplies dry air from the dry air supply pipe 250 when the dew point temperature is out of the predetermined range. When the dew point temperature becomes equal to or lower than the set value, the controller stops supplying dry air.
As a result, the relative humidity in the test space S is controlled, and dew condensation on the test object is suppressed.

If coolant leaks or condensation occurs during the power cycle test, the leakage sensor 320 detects this, and the control section stops the power cycle test.
The leaked coolant or water due to condensation stays inside the liquid leakage suppressing member 310 and is discharged from the liquid drain hole H2, so that leakage to the outside of the mounting table 202 is suppressed.

As described above, according to the power cycle test apparatus 10, dry air is supplied from the dry air supply pipe 250, and the relative humidity in the test space S is appropriately controlled, so that the occurrence of dew condensation during the power cycle test is suppressed. be.
As a result, the power cycle test can be performed in a wider temperature range (including 0° C. or lower).

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and all modifications of conditions that do not deviate from the gist of the present invention are within the scope of the present invention.

10 power cycle test device 12 liquid cooling heat sink 14 power module with liquid cooling heat sink 122a first tube connection part 122b second tube connection part 20a first test part 20b second test part 50 drive power supply part 202 Stand 204 Cover 206 Hinge 210 First terminal block 212 Plate member 220 Second terminal block 230 Coolant discharge pipe 240 Coolant supply pipe 250 Dry air supply pipe 260 Thermo-hygrometer 270 Electromagnetic lock 280 Bypass pipe 290 Valve 310 Leakage Control member 315 Drainage pipe 320 Liquid leakage sensor 322 Amplifier 324 Detection band 326 Connection terminal block 328 Terminator A Placement area AX Rotating shaft H1 Wiring hole H2 Drainage hole PM Power module S Test space TM1, TM2, TM3 Main terminals

Claims (7)

a mounting table provided with a mounting area on which a power module attached to a liquid-cooled heat sink and having terminals is mounted;
a cover for covering the mounting table and forming a test space therein;
A power cycle testing device that energizes the power module and tests the power module,
a cable connection portion to which a cable extending to the terminal is connected;
a tube portion to which a tube for flowing cooling liquid is connected to the liquid-cooled heat sink;
a dry air supply pipe for supplying dry air maintained at a predetermined relative humidity or less;
a temperature and humidity measurement unit that measures the temperature and relative humidity inside the test space;
A control unit that controls the supply of the dry air,
The cable connection portion, the pipe portion, the dry air supply pipe and the temperature/humidity measurement portion are provided inside the test space,
A power cycle test apparatus in which the dry air is supplied until the dew point temperature obtained based on the temperature and the relative humidity measured by the temperature and humidity measurement unit is equal to or lower than a predetermined set value. In the power cycle test device according to claim 1,
The first cable connection portion and the second cable connection portion are arranged with a gap in the left-right direction across the mounting area when viewed from the front,
A power cycle test apparatus, wherein the cooling liquid supply pipe and the cooling liquid discharge pipe are arranged at positions on the rear end side of the upper surface of the mounting table. In the power cycle test device according to claim 2,
a liquid leakage suppressing member that protrudes from the upper surface of the mounting table and is provided for suppressing leakage of the cooling liquid to the outside;
and a liquid leakage sensor that detects the leaked cooling liquid,
A power cycle test apparatus, wherein the mounting table inside the leakage suppressing member is provided with a drainage hole for discharging leaked coolant. In the power cycle test device according to claim 3,
wherein the liquid leakage sensor has a detection band arranged inside the liquid leakage suppressing member,
A power cycle test apparatus, wherein the detection band is arranged so as to surround at least the mounting area and the cooling liquid supply pipe in plan view. In the power cycle test device according to claim 4 ,
A power cycle test apparatus further comprising a bypass pipe that connects the cooling liquid supply pipe and the cooling liquid discharge pipe with each other and is provided with a valve that opens and closes a flow path. A power cycle test method using the power cycle test device according to claim 1,
The power module with a liquid-cooled heat sink is mounted on the mounting area, and the first cables are provided between the control terminal and the first cable connection portion and between the main terminal and the second cable connection portion, respectively. a preparation step in which the cable of and the second cable are connected;
a test step in which the power module is energized in a predetermined cycle after the preparation step is performed;
a dew point temperature management step in which, when the dew point temperature deviates from a predetermined range , the control unit supplies the dry air until the dew point temperature becomes equal to or lower than a predetermined set value. Test method. In the power cycle test method according to claim 6 ,
In the test step, the control unit supplies the dry air until the dew point temperature becomes equal to or lower than a predetermined set value before the power module is energized.