Power cycle testing equipment

Abstract

Modifying wiring connections to match test items requires a long time. Furthermore, it's difficult to accurately measure changes in the characteristics of the semiconductor elements being tested. [Solution] A conductor plate 204 and a switch circuit 124 are mounted on a switch circuit board 201. Multiple switch circuit boards 201 are arranged in parallel, and the conductor plate 204 of each switch circuit board 201 has a portion that extends beyond the switch circuit board 201. Wiring 211 is connected to the element terminal 226 of the transistor 117 to be tested and to the portion of the conductor plate 204 that extends beyond the selected switch circuit board 201. When the switch circuit 124 of the selected switch circuit board 201 is turned on, the test current from the power supply 132 is supplied to the transistor 117 to be tested, and a power cycle test is performed. During the test of the semiconductor element 117, an on voltage and a first off voltage are applied to perform a continuous test, and a second off voltage is applied to measure the characteristics.

Description

Technical Field

[0001] The present invention relates to an electric element test apparatus for performing a power cycle test on semiconductor elements such as SiC, IGBT, MOS-FET, Gan-FET, bipolar transistors, and a test method for electric elements.

[0002] Provided are a semiconductor element test apparatus and a test method for semiconductor elements that can efficiently reproduce stress close to a failure mode in the usage environment of a semiconductor element and evaluate a power semiconductor element or the like with high reliability.

Background Art

[0003] The life of a power semiconductor element includes the life due to a thermal fatigue phenomenon caused by heat generation of the power semiconductor element itself and the life due to a thermal fatigue phenomenon caused by a temperature change in the external environment of the power semiconductor element. In addition, there is a life due to voltage fatigue caused by an applied voltage to the gate insulating film of the power semiconductor element.

[0004] Generally, a life test of a power semiconductor element is performed by repeatedly turning on and off the power supply to the semiconductor element. For example, a test is performed by setting an applied voltage and current to the emitter terminal (source terminal), collector terminal (drain terminal), etc. of the transistor of the semiconductor element and applying a periodic on / off signal (operation / non-operation signal) to the gate terminal.

[0005] The current applied to the semiconductor element during the test is as large as several hundred amperes, and low-resistance wiring is required to avoid heat generation and voltage drop. Since the test current is large, it is necessary to connect the connection part between the semiconductor element and the wiring with low resistance. In addition, there are many types of tests, and it is necessary to change the connection of the wiring according to the type of test.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Conventional semiconductor device testing equipment performs tests on power semiconductor devices (transistors, etc.) by switching transistor 117 on and off and simultaneously applying a constant current Id to the transistor's channel.

[0008] The semiconductor device test equipment (power cycle test equipment) performs a wide variety of test items, and it is necessary to change the connection to transistor 117 according to the test item.

[0009] The constant current Id is often several hundred amperes or more, requiring the use of thick wires for the connecting wiring 211 and power supply wiring 212 that carry this current. Furthermore, a large current Id flows through the semiconductor element terminals. If there is contact resistance between the semiconductor element terminals and the connecting wiring, the contact area will overheat, potentially damaging the semiconductor element.

[0010] Changing the wiring connections of thicker wires to accommodate test items is time-consuming and requires workspace, which poses the challenge of increasing the size of the test equipment. [Means for solving the problem]

[0011] The semiconductor device testing apparatus of the present invention has a connecting structure 218 that connects to the element terminals 226 of the semiconductor device to be tested. One end of the connecting structure 218 has a contact portion 220 that contacts the element terminals 226, and a peat pipe 223 is attached to the surface of the connecting structure 218. The connecting structure 218 is electrically connected to the element terminals 226 of the semiconductor device 117 to be tested by inserting it into an opening 216 formed in a partition wall 217, or / or by inserting it into a groove in a support base 323.

[0012] The semiconductor device testing apparatus of the present invention separates the area (space) within the semiconductor device testing apparatus where the transistor 117 to be tested is placed from the area where the circuit board is placed for generating the test current for the transistor 117, generating the control signal, and acquiring the test results. A partition wall is provided for separation.

[0013] The connection between the transistor being tested and the circuit board is made by inserting a fork plug 205 (connecting plug 205) through an opening 216 provided in the partition wall 214, and bringing the connecting plug 205 into contact with a conductive plate on the circuit board. [Effects of the Invention]

[0014] Because there is contact resistance at the connection point between the element terminal 226 of the transistor 117 being tested and the connecting structure 218, the contact point generates heat when a large current flows. In this invention, since a heat pipe 223 is arranged in the connecting structure 218, the generated heat can be efficiently dissipated by heat conduction. Since the element terminal 226 and the connecting structure 218 are inserted through an opening 216 in the partition wall 217, etc., it is easy to attach and detach them from the transistor 117 being tested, and the connection to the transistor 117 being tested can be changed in a short time.

[0015] A partition wall 214 is provided to separate the area (space) within the semiconductor device test apparatus where the transistor 117 is placed from the area where the circuit board is placed for generating the test current for the transistor 117, generating the control signal, and acquiring the test results. A connecting plug 205 is inserted through an opening 216 in the partition wall 214, and the connecting plug 205 is connected to the conductive plate 204 on the circuit board. This eliminates the need for connection work of connection wiring 211 for each test item, does not require workspace for changing wiring connections, and allows for miniaturization of the semiconductor device test apparatus. [Brief explanation of the drawing]

[0016] [Figure 1] This is an explanatory diagram of the electrical element testing apparatus of the present invention. [Figure 2]It is an explanatory diagram of a connection method between an electric element test apparatus and an electric element of the present invention. [Figure 3] It is an explanatory diagram of a connection part of an electric element test apparatus of the present invention. [Figure 4] It is an explanatory diagram of a connection part of an electric element test apparatus of the present invention. [Figure 5] It is an explanatory diagram of a connection part of an electric element test apparatus of the present invention. [Figure 6] It is an explanatory diagram of a connection part of an electric element test apparatus of the present invention. [Figure 7] It is an explanatory diagram of a connection method between an electric element test apparatus and an electric element of the present invention. [Figure 8] It is a configuration diagram of an electric element test apparatus of the present invention. [Figure 9] It is an explanatory diagram of an electric element test apparatus of the present invention. [Figure 10] It is an explanatory diagram of an electric element test apparatus of the present invention. [Figure 11] It is an explanatory diagram of an electric element test apparatus of the present invention. [Figure 12] It is a structural diagram and an equivalent circuit diagram of an electric element. [Figure 13] It is a structural diagram and an equivalent circuit diagram of an electric element. [Figure 14] It is an explanatory diagram of an electric element test apparatus of the present invention. [Figure 15] It is an explanatory diagram of a connection method between an electric element test apparatus and an electric element of the present invention. [Figure 16] It is a configuration diagram and an explanatory diagram of a connection structure of the present invention. [Figure 17] It is a configuration diagram and an explanatory diagram of a connection structure of the present invention. [Figure 18] It is a configuration diagram and an explanatory diagram of a connection structure of the present invention. [Figure 19] It is a configuration diagram and an explanatory diagram of a connection structure of the present invention. [Figure 20] It is a configuration diagram and an explanatory diagram of a connection structure of the present invention. [Figure 21] It is a configuration diagram and an explanatory diagram of a connection structure of the present invention. [Figure 22]A diagram illustrating the configuration and explanatory diagram of the connection structure of the present invention. [Figure 23] This is an explanatory diagram of the connection section of the electrical element testing apparatus of the present invention. [Figure 24] This is an explanatory diagram of the connection section of the electrical element testing apparatus of the present invention. [Figure 25] This is an explanatory diagram of the electrical element testing apparatus of the present invention. [Figure 26] This is a diagram showing the configuration of the electrical element testing apparatus of the present invention. [Figure 27] This is an explanatory diagram of the electrical element testing apparatus of the present invention. [Figure 28] This is an explanatory diagram of the electrical element testing apparatus of the present invention. [Figure 29] This is an explanatory diagram of the operation of the electrical element testing apparatus in the first embodiment of the present invention. [Figure 30] This is an explanatory diagram of the operation of the electrical element testing apparatus in the first embodiment of the present invention. [Figure 31] This is an explanatory diagram of the operation of the electrical element testing apparatus in the first embodiment of the present invention. [Figure 32] This is an explanatory diagram of the operation of the electrical element testing apparatus in the first embodiment of the present invention. [Figure 33] This is an explanatory diagram of the operation of the electrical element testing apparatus in the first embodiment of the present invention. [Figure 34] This is an explanatory diagram of the operation of the electrical element testing apparatus in a second embodiment of the present invention. [Figure 35] This is an explanatory diagram of the operation of the electrical element testing apparatus in the third embodiment of the present invention. [Figure 36] This is an explanatory diagram of the operation of the electrical element testing apparatus in the fourth embodiment of the present invention. [Figure 37] This is an explanatory diagram of the operation of the electrical element testing apparatus in the fourth embodiment of the present invention. [Figure 38] This is an explanatory diagram of a power semiconductor device. [Modes for carrying out the invention]

[0017] The following describes an electrical element testing apparatus and electrical element testing method according to an embodiment of the present invention, with reference to the attached drawings.

[0018] In the embodiments described in this specification, IGBTs are used as an example among power semiconductor devices. The present invention is not limited to IGBTs and can be applied to various power semiconductor devices such as SiC, MOSFETs, JFETs, and transistors. Furthermore, the present invention is not limited to transistors but can also be applied to two-terminal devices such as diodes.

[0019] Furthermore, it goes without saying that the present invention is not limited to power semiconductor devices, but can also be applied to electronic devices such as low-power semiconductor devices, signal control semiconductor devices, resistors, capacitors, coils, crystal oscillators, and thermistors.

[0020] In the drawings illustrating embodiments for carrying out the invention, elements having the same function are denoted by the same reference numeral, and their descriptions may be omitted. Furthermore, the embodiments of the present invention can be combined from one another.

[0021] Figure 8 is a diagram showing the configuration of the power cycle test apparatus (semiconductor device test apparatus) of the present invention. The power cycle test apparatus has a chiller (cooling / heating device) 136, a heating / cooling plate 134, and a circulating water pipe 135 that circulates water between the heating / cooling plate 134 and the chiller 136. A transistor 117, which is the semiconductor device to be tested, is mounted on the heating / cooling plate 134. The test conditions are set by changing the current Id, gate voltage Vgs, and voltage Vce so that the temperature information Tj of the transistor 117 under test reaches a predetermined value.

[0022] When the temperature information Tj changes, it is determined that transistor 117 has deteriorated or its characteristics have changed, and the test of transistor 117 is stopped or the control method is changed.

[0023] The current flowing through or applied to transistor 117 will be described as a constant current Id, but the present invention is not limited to this. It goes without saying that Id may be a current that changes with a predetermined period or time. Furthermore, it is not limited to current, but may also be voltage.

[0024] The change in temperature information Tj determines or detects the change in the characteristics of transistor 117. In addition, the change in characteristics, reliability, and lifespan of transistor 117 are evaluated from the time it takes for the voltage Vce to reach a predetermined voltage, the time until transistor 117 fails, etc.

[0025] In the semiconductor testing method of the present invention, external conditions are changed in accordance with the degradation or characteristic change of transistor 117. For example, if transistor 117 generates heat, the water temperature is lowered. Lowering the water temperature reduces the current flowing through transistor 117, which prevents the degradation and characteristic change of transistor 117 from progressing, and as a result, extends the lifespan of transistor 117. Therefore, the lifespan and reliability characteristics of transistor 117 under predetermined set conditions can be quantitatively measured and judged.

[0026] The temperature of the transistor 117 is maintained at a specified or predetermined value by heating or cooling the circulating water in the chiller 136. Furthermore, the temperature of the transistor and other components is periodically changed, cooled, or heated in accordance with the test conditions. The temperature information Tj of the test transistor is measured, and the chiller 136 is controlled to maintain the measured temperature information Tj at a constant value.

[0027] A chiller is designed to maintain a constant temperature for equipment by circulating water or a heat transfer medium while controlling its temperature. While primarily used for cooling, it can also heat. It is configured to allow for various temperature control applications.

[0028] The control rack 131 includes a power supply unit 132 that supplies test current and test voltage to the transistor 117, and a control circuit 133 that controls the transistor 117 or sets test conditions.

[0029] The control circuit 133 receives temperature information Tj from the transistor 117 and controls the chiller 136 based on the temperature information Tj. Alternatively, it controls the chiller 136 to bring the temperature information Tj to a predetermined value.

[0030] In this specification, the circulating water is used, but it is not limited to water. It may also be ethylene glycol, glycerin, Freon, etc., or forced air cooling may be used. The chiller 136 supplies the liquid in the circulating water pipe 135 to the heating and cooling plate 134 of the test unit, controlling the temperature within a range, for example, from -1°C to +100°C. The heating and cooling plate 134 has a sufficiently large heat capacity.

[0031] In the above embodiment, a heating and cooling plate 134 was used, but the heating plate and the cooling plate may be separate components, and heating and cooling may be performed using heat sources and cold sources other than the heating and cooling plate.

[0032] Figure 11 is a configuration diagram of a semiconductor device testing apparatus (for example, a power cycle testing apparatus for testing power transistors) in a first embodiment of the present invention. Figure 29 is an equivalent circuit diagram or explanatory diagram of the semiconductor device testing apparatus.

[0033] The power supply unit 132 has a current power supply circuit 121 and a switch circuit 122. The current power supply circuit 121 outputs a high-current constant current Id for testing the transistor 117. The current power supply circuit 121 supplies power (current, voltage) in synchronization with the control signal from the control circuit board 111 (controller 111), and uses the supplied power to drive the load with a set constant current or constant voltage. The current power supply circuit 121 can also set the maximum output voltage value.

[0034] The switch circuit 122 (SWa) turns the constant current supply output by the current power supply circuit 121 on (supplies) or off (cuts off). The switch circuit 122 is set or controlled to be on (outputs constant current) or off (cuts off constant current) based on a signal from the control circuit board (controller) 111. Normally, the switch circuit 122 is turned on before the start of testing and is kept on at all times during the testing of the semiconductor device.

[0035] Figure 11 illustrates one current power supply circuit 121. However, the current power supply circuit 121 is not limited to one unit. For example, the semiconductor device testing apparatus of the present invention may have two or more current power supply circuits 121. The more current power supply circuits 121 there are, the more diverse the current waveforms Id that can be generated.

[0036] In the embodiments of the present invention, the power supply device 132 is described as having a current power supply circuit 121 that outputs current, but the current power supply circuit 121 is not limited to one that outputs a constant current.

[0037] For example, the current power supply circuit 121 may be one that allows setting a maximum voltage. An example is to configure it to output a predetermined constant current at the set maximum voltage under certain conditions. Another example is to configure it so that the output terminal voltage can be set to a predetermined maximum voltage when outputting a constant current. Needless to say, in the semiconductor device testing apparatus of the present invention, the current power supply circuit 121 may not be a device that outputs only a constant current, but may be a power supply device that can output voltage and current.

[0038] In the embodiments shown in Figure 11 and other examples, the current Id is described as being generated by the current power supply circuit 121. However, the current Id can also be achieved by adjusting the applied voltage according to the on-resistance state of the transistor 117. Therefore, it goes without saying that the semiconductor device testing apparatus of the present invention is not limited to the current power supply circuit 121 that outputs current, but may also be configured with a voltage-outputting power supply device.

[0039] The current Id can also be achieved by controlling the voltage value of the gate voltage of transistor 117. In this specification, it is described that a predetermined current is applied to transistor 117 by controlling the current power supply circuit 121. However, this is not the only way, and it goes without saying that the voltage at the gate terminal g of transistor 117 and the voltage at the collector terminal c of transistor 117 may also be adjusted or controlled.

[0040] In the embodiment of the first semiconductor device test method of the present invention, for the sake of simplicity, it is assumed that the constant current Id is generated by the current power supply circuit 121. The current Id that flows through the transistor 117 is supplied by operating the current power supply circuit 121. The current power supply circuit 121 is turned on / off by a signal from the control circuit board (controller) 111. The device control circuit board 209 is timing-controlled by the control circuit board (controller) 111.

[0041] The emitter terminal e of transistor 117 is grounded (connected to the ground line). The gate terminal g of transistor 117 is connected to the gate driver circuit 113.

[0042] The sample connection circuit 203 contains or has a gate driver circuit 113, a variable resistor circuit 125, a constant current circuit 118, and an operational amplifier (buffer circuit) 116. The sample connection circuit 203 is positioned separately from the device control circuit board 209 so that it can be placed close to the transistor 117 to be tested.

[0043] It is preferable to provide one sample connection circuit 203 for each transistor 117 to be tested, but it is not limited to this, and one sample connection circuit 203 containing multiple signal circuits may be provided for multiple transistors 117.

[0044] The sample connection circuit 203 is connected to transistor 117 via connection pin 206 of connector 202. The distance between the gate driver circuit 113 and the gate terminal g of transistor 117 is short, less than 30 mm. If the distance between the gate driver circuit 113 and the gate terminal g of transistor 117 is long, noise and other interference will be superimposed on the gate terminal g, causing transistor 117 to malfunction and directly leading to its destruction.

[0045] As shown in Figure 9, the device control circuit board 209 is located in chamber B of the housing 210 of the semiconductor device test apparatus. The housing 210 is a frame or main body of the semiconductor device test apparatus, incorporating the power supply unit 132, drive circuit, and heating / cooling plate 134. The sample connection circuit 203 is located in chamber C1 of the housing 210 of the semiconductor device test apparatus, in order to be positioned close to the transistor 117 to be tested. The sample connection circuit 203 is connected to a connector 208 located on the side of the housing 210. The wiring connected to the connection pin 206 of the connector 208 is connected to the device control circuit board 209 in chamber B.

[0046] The enclosure 210 is not limited to a box shape; it could be, for example, a room. The image shows the current power supply circuit 121 being placed inside the room. Partition walls 214, 215, and 217 could be the walls of the room.

[0047] As shown in Figure 9, the semiconductor element 117 (transistor, etc.) to be tested is placed in chamber C1. The transistor 117, etc., is placed and fixed in close contact with the heating and cooling plate 134. If necessary, the transistor 117, etc., is fixed by being sandwiched between the heating / cooling plate 134a and the heating / cooling plate 134b, as shown in Figure 15.

[0048] As described above, in the present invention, the housing 210 is divided into multiple regions such as the C1 chamber. Dry air (a dry gas, a gas with a low dew point temperature) is injected into the C1 chamber. Air pressure is applied to the C1 chamber, and the air injected into the C1 chamber is discharged through an opening 216 or the like.

[0049] As shown in Figures 1 and 9, the connecting structure 218 is inserted from the C2 chamber through the opening 216 of the partition wall 217. By inserting the connecting structure 218, an electrical connection is made between the element terminal 226 of the transistor 117 and the connecting structure 218, allowing a constant current (test current) Id to be applied to the transistor 117. Also, as shown in Figures 23 and 24, the connecting structure 218 is placed in a groove of the support base 323 and inserted into the element terminal 226 of the transistor 117. By inserting the connecting structure 218, an electrical connection is made between the element terminal 226 of the transistor 117 and the connecting structure 218.

[0050] The partition wall 217 functions as an electrostatic shield and as a holder for the connecting structure 218. Needless to say, if a separate electrostatic shielding component and a fixing or holding base for the connecting structure 218 are provided or configured, the partition wall 217 can be omitted. Furthermore, it goes without saying that if there is no partition wall 217, the element terminals 226 of the transistor 117 may be positioned and fixed to the connecting structure 218.

[0051] The partitions (partitions 214, 215, and 217) serve to separate each chamber (chamber C1, chamber C2, chamber A, and chamber B) and to prevent outside air from flowing in. In particular, since condensation may occur in chamber C1 during low-temperature testing, dry air is introduced into chamber C1. The dry air that flows into chamber C1 is discharged to the other chambers through opening 216. However, if the opening of opening 216 is large, a large amount of dry air will be required. Therefore, it is preferable that the opening 216 be sized to allow the fork plug 205 and connecting structure 218, which serve as connecting members, to be inserted just in time.

[0052] A fixing screw 221 is attached to the other end of the connecting structure 218, and the connecting wiring 211 is connected to the connecting structure 218. A fork plug 205, which serves as a connecting member, is attached to the other end of the connecting wiring 211. The connecting structure 218 is made of copper or a copper alloy and its surface is plated with silver or nickel.

[0053] The fixing screw 221 is not limited to a screw; any type that can electrically connect the connecting wiring 211 to the connecting structure 218 is acceptable. Furthermore, it goes without saying that the fixing screw 221 may also be one that can be pressed into contact by a spring (not shown).

[0054] The sample connection circuit 203 is connected to the device control circuit board 209 by the connection pins 206 of the connector 208. Each sample connection circuit 203 is individually positioned to correspond to each transistor 117 to be tested, and the sample connection circuits 203 are configured to be easily removable. Connectors 208 and 213 are not limited to connectors; any device that can electrically connect or disconnect wiring may be used.

[0055] Figure 3 is an explanatory diagram of the connection structure 218 in the semiconductor device testing apparatus of the present invention. Figure 3(a) is a schematic diagram showing the back surface, and Figure 3(b) is a schematic diagram showing the side surface.

[0056] The heat pipe 223 is in close contact with the recess 234 on the surface of the connecting structure 218. Thermal conductive grease or heat dissipation silicone oil compound may be applied between the surface of the connecting structure 218 and the heat pipe.

[0057] In the present invention, the connection structure 218 has a heat pipe 223 arranged on the side of the connection fitting portion 233. It is preferable that the heat pipe fitting 231 and the connection fitting portion 233 are integrated. The connection fitting portion 233 and the element terminal 226 are in electrical contact, and a test current is supplied to the semiconductor element 117, etc.

[0058] The connecting fitting 232 contacts the element terminal 226, sandwiching the element terminal 226 between the connecting fitting portion 233 and the connecting fitting 232. The connecting fitting 232 is not required to be made of a conductive material such as metal. It is preferable to configure the device so that no test current flows through the connecting fitting 232.

[0059] The connecting structure 218 of the present invention has a recess 234 formed therein, into which the heat pipe 223 is fitted. The heat pipe fitting 231 of the connecting structure 218 is made of a material whose coefficient of thermal expansion is smaller than that of the heat pipe 223.

[0060] The connection portion of the connecting structure 218 with the element terminal 226 generates heat, and the connecting structure 218 is heated. Consequently, the heat pipe 223 and the heat pipe fitting 231 are heated. Due to the heating, the heat pipe 223 and the heat pipe fitting 231 expand.

[0061] In this invention, the heat pipe fitting 231 of the connecting structure 218 is made of a material with a lower coefficient of thermal expansion than the heat pipe 223, or the heat pipe 223 of the connecting structure 218 is made of a material with a higher coefficient of thermal expansion than the heat pipe fitting 231. The heat pipe 223 material expands more within the recess 234, causing the heat pipe 223 to be fitted more firmly into the recess 234. Therefore, the heat pipe 223 will not come loose.

[0062] Examples of materials for the heat pipe fitting 231 include copper (linear expansion coefficient 16.8), brass (linear expansion coefficient 19), iron (linear expansion coefficient 12.1), and stainless steel (SUS304) (linear expansion coefficient 17.3). Examples of materials for the heat pipe 223 include materials with a higher linear expansion coefficient than the heat pipe fitting 231, such as aluminum (linear expansion coefficient 23), tin (linear expansion coefficient 26.9), and lead (linear expansion coefficient 29.1). Among these, it is preferable to use copper (linear expansion coefficient 16.8) for the heat pipe fitting 231 and aluminum (linear expansion coefficient 23) for the heat pipe 223.

[0063] The rate at which length changes in response to an increase in temperature is called the linear expansion coefficient (or linear expansion coefficient). Similarly, the rate at which volume changes is called the volume expansion coefficient. If the linear expansion coefficient is α and the volume expansion coefficient is β, then the relationship β ≈ 3α holds. The thermal expansion coefficient is the rate at which the length and volume of an object expand (thermal expansion) per unit of temperature due to an increase in temperature. It is also called the thermal expansion coefficient.

[0064] The present invention states that it is preferable for the heat pipe fitting 231 of the connecting structure 218 to be made of a material with a coefficient of linear expansion smaller than that of the heat pipe 223, or for the heat pipe 223 of the connecting structure 218 to be made of a material with a coefficient of linear expansion larger than that of the heat pipe fitting 231. However, it goes without saying that the coefficient of linear expansion may be replaced with the coefficient of thermal expansion or the coefficient of volumetric expansion.

[0065] The recess 234 is formed in the heat pipe fitting 231. The heat pipe 223 is positioned so as to fit into the recess 234. Positioning the heat pipe 223 in the recess reduces the risk of damage to the heat pipe 223.

[0066] The heat pipe fitting 231 is made of a metal that is electrically conductive and has good thermal conductivity. Examples of such metals include copper and silver. Other materials such as carbon can also be used.

[0067] For thermal conductive grease, it is preferable to use one that contains boron nitride. For heat dissipation silicone oil compound, it is preferable to use one that uses silicone oil as a base oil and is blended with a powder with good thermal conductivity such as alumina. A heat pipe 223 is a sealed container in which a small amount of liquid (working fluid) is vacuum-sealed, and which has a capillary structure (wick) on its inner wall.

[0068] When a portion of the heat pipe is heated, the working fluid evaporates in the heated section (absorbing latent heat of vaporization), and the vapor moves at high speed (sonic speed) to the cooler section. The vapor condenses in the cooler section (releasing latent heat of vaporization), and the condensed working fluid recirculates to the heated section through the capillary action of the wick. As these phase changes are continuously repeated without external force, heat is transferred instantaneously, enabling high-speed and efficient heat transfer from the terminal portion of the semiconductor element.

[0069] The heat pipe 223 is constructed by arranging multiple containers (copper pipes). The inside of each container is under a highly reduced pressure and contains a wick (capillary structure) and an appropriate amount of working fluid (pure water, etc.). In addition to pure water, methanol (methyl alcohol), acetone, sodium, mercury, fluorocarbon refrigerants, and ammonia may be used as the working fluid. Wick materials include aluminum, copper, stainless steel, sintered alloys, wire mesh, foamed metal, and ceramics.

[0070] The connecting structure 218 is not limited to metal. For example, it may be made of non-metallic materials such as ceramic, graphite, or composite materials of graphite and copper or aluminum. In the case where current is directly passed through the connecting structure 218, the connecting structure 218 is made of a metallic material such as copper. The surface of the connecting structure 218 is preferably plated with silver, nickel, or the like.

[0071] As shown in Figure 3, the connection structure 218 mainly consists of a heat pipe fitting 231, a connecting fitting 232, and a connecting fitting portion 233. The element terminal 226 of the semiconductor element is inserted between the connecting fitting 232 and the connecting fitting portion 233.

[0072] Figure 12 is an explanatory diagram of the semiconductor element 117 to be tested. A transistor is used as an example of the semiconductor element 117. The transistor 117 has a P terminal (collector terminal of the transistor 117) to which a large current is applied and an N terminal (emitter terminal of the transistor 117) to which a large current is applied. A diode Di is formed or added between the emitter terminal and the collector terminal. A test current Id is applied to the P terminal and the N terminal.

[0073] Transistor 117 has a collector terminal c, a gate terminal g, and an emitter terminal e. A signal Vgs is applied to the gate terminal g to switch transistor 117 on and off. A constant current Ic is supplied from the constant current circuit 118 to the diode Di, which is connected to the emitter terminal e and collector terminal c.

[0074] Contact portions 225a and 225b are positioned between the connecting fitting 232 and the connecting fitting portion 233. Platinum, gold, silver, tungsten, copper, nickel, or alloys combining these materials can be used as the contact portion 225. It is also preferable to use silver oxide contact materials (Ag+ZnO, Ag+SnO2, Ag+SnO2In2O3, Ag+, Ag+SnO2Sn2Bi2O7).

[0075] As an example, the connecting fitting portion 233 is integrated with the heat pipe fitting 231. The connecting fitting 232 is fixed to the connecting fitting portion 233 with fixing screws 224b. The element terminals 226 of the semiconductor element are fixed by tightening the fixing screws 224b. The connecting wiring 211 is fixed to the left end of the heat pipe fitting 231 with fixing screws 221.

[0076] Figure 15 is an explanatory diagram showing the element terminal 226 connected to the connecting structure 218. The element terminal 226 is sandwiched between contact portions 225a and 225b. The connecting fitting 232 is fixed to the element terminal 226 by fixing screws 224b.

[0077] The transistor 117 is fixed to the heating / cooling plate 134a and further clamped by the heating / cooling plate 134b. The transistor 117 is properly maintained at the test temperature by the heating / cooling plate 134. A heat pipe 223 is mounted in the recess 234.

[0078] A test constant current Id is applied from the connection structure 218 to the element terminal 226. The constant current Id is large, several hundred amperes (A). The element terminal 226 is small, and there is contact resistance between the contact portion 225 and the element terminal 226. Therefore, when a large current flows through the element terminal 226, the contact portion 225 generates heat.

[0079] The heat generated is conducted to the transistor 117 being tested, causing it to overheat. Overheating can lead to degradation of the transistor 117 or burnout of the element terminals 226. Therefore, it is necessary to quickly dissipate the heat generated at the contact points 225.

[0080] The connection structure 218 of the present invention has a heat pipe 223. Heat generated at the contact point 225 is transferred by the heat pipe 223. Therefore, the heat at the contact point 225 is quickly removed from the contact point 225.

[0081] A partition wall 217 is located between room C1 and room C2. As shown in Figure 14, an opening 216 is formed in the partition wall 217. A connecting structure 218a1 is inserted into opening 216a1, and a connecting structure 218b1 is inserted into opening 216b1. A connecting structure 218a2 is inserted into opening 216a2, and a connecting structure 218b2 is inserted into opening 216b2. A connecting structure 218an is inserted into opening 216an, and a connecting structure 218bn is inserted into opening 216bn.

[0082] For example, in the semiconductor device testing apparatus shown in Figure 36, the P terminal of the transistor 117Q1 to be tested is electrically connected by being sandwiched between the connecting fitting 232 and the connecting fitting portion 233 of the connecting structure 218a1. Similarly, the N terminal of the transistor 117Q1 to be tested is electrically connected by being sandwiched between the connecting fitting 232 and the connecting fitting portion 233 of the connecting structure 218b1.

[0083] Similarly, the P terminal of the transistor 117Q2 to be tested is sandwiched between the connecting fitting 232 and the connecting fitting portion 233 of the connection structure 218a2, thereby making an electrical connection. In addition, the N terminal of the transistor 117Q2 to be tested is sandwiched between the connecting fitting 232 and the connecting fitting portion 233 of the connection structure 218b2, thereby making an electrical connection.

[0084] Similarly, the P terminal of the transistor 117Qn to be tested is sandwiched between the connecting fitting 232 and the connecting fitting portion 233 of the connection structure 218an, thereby making an electrical connection. In addition, the N terminal of the transistor 117Qn to be tested is sandwiched between the connecting fitting 232 and the connecting fitting portion 233 of the connection structure 218bn, thereby making an electrical connection.

[0085] The partition wall 217 is equipped with an electromagnetic shielding plate, an electrostatic shielding plate, or an electromagnetic shielding mesh, an electrostatic shielding mesh, etc., to shield noise from the power supply unit 132 and the drive circuit system of room B, so that the noise is not applied to room C1. In addition, the noise generated by the on / off switching of transistor 117 is not applied to the drive circuit system of room B.

[0086] Figure 1 is an explanatory diagram illustrating the connection state between the transistor 117 and the connecting structure 218. The transistor 117 is fixed in close contact with the heating / cooling plate 134a. Fixation is performed by a spring (not shown). Close contact may also be achieved by applying thermal conductive grease or heat dissipation silicone oil compound. If necessary, as shown in Figure 15, a heating / cooling plate 134b is also placed above the transistor 117 to allow the transistor 117 to be set to a predetermined temperature condition.

[0087] Connector 202 is connected to the terminals of transistor 117 (emitter terminal e, gate terminal g, and collector terminal c). Signal wiring 222 is drawn out from connector 202. The control signal Vgs applied to the gate terminal g of transistor 117 and the constant current Ic from the constant current circuit 118 are applied to signal wiring 222.

[0088] The connecting structure 218a is inserted into the opening 216a of the partition wall 217 from the C2 chamber side. Similarly, the connecting structure 218b is inserted into the opening 216b of the partition wall 217 from the C2 chamber side. When the connecting structure 218 is inserted, the element terminal 226 is sandwiched between the connecting fitting 232 and the connecting fitting portion 233. In this state, the element terminal 226 of the transistor 117 and the connecting structure 218 are electrically connected by tightening the fixing screw 224b.

[0089] Since the transistor 117 to be tested needs to be fixed in close contact with the heating / cooling plate 134, it is difficult to remove it easily. The installation process for the transistor 117 involves first fixing multiple transistors 117 to be tested to the heating / cooling plate 134. Next, the transistor 117 to be tested first is selected and the connection structure 218 is attached to the element terminal 226.

[0090] The selected transistor 117 is electrically connected to the element terminal 226 by inserting the connecting structure 218 from the C2 chamber side into the opening 216 where the selected transistor 117 is located.

[0091] Electrical connection to transistor 117 is easy, as it only requires selecting the position for inserting the connection structure 218. Furthermore, the test conditions and test content for transistor 117 can be easily changed by modifying the applied signal to the connection wiring 211 connected to the connection structure 218.

[0092] The element terminal 226 is held by contact portions 225a and 225b under pressure. A connecting wire 211 is connected to one end of the connecting structure 218, and a constant current Id is applied to the transistor 117 from the connecting wire 211. A heat pipe 223 is located on the back side of the connecting structure 218.

[0093] A current of several hundred amperes (A) flows through the element terminal 226. Even with a small resistance at the contact point 225, the current of several hundred amperes (A) generates a large amount of heat, overheating the element terminal 226. This overheating will also overheat the transistor 117, causing it to deteriorate or be destroyed.

[0094] In this invention, the heat generated at the contact point 225 is transferred to the connecting wiring 211 side of the connecting structure 218 by the heat pipe 223. Therefore, the contact point 225 will not overheat. A cooling fan 227 is positioned below the connecting structure 218 to dissipate the heat from the heat pipe 223. Figure 2 is an explanatory diagram illustrating the method of connecting the semiconductor element 117 and the connecting structure 218 in the semiconductor testing apparatus of the present invention.

[0095] A partition wall 217 is provided between chamber C1 and chamber C2. As shown in Figure 14, an opening 216 is formed in the partition wall 217 corresponding to the position of the transistor 117, etc. to be tested. The opening 216 in the partition wall 217 and the fixing base (not shown) of the connecting structure 218 position and fix the connecting structure 218 horizontally or stably.

[0096] As shown in Figure 2(a), the transistor 117 to be tested is positioned and fixed in close contact with the heating / cooling plate 134a. Thermal conductive grease and heat dissipation silicone oil compound are applied between the transistor 117 and the heating / cooling plate 134a.

[0097] A detachable connector 202 is connected to the terminals of transistor 117 (emitter terminal e, gate terminal g, and collector terminal c). A signal wire 222 is connected to the connector 202, and the signal wire 222 is connected to the sample connection circuit 203.

[0098] The signal wiring 222 between the sample connection circuit 203 and the connector 202 should be made as short as possible. If the signal wiring 222 is long, noise will be superimposed on it, causing the transistor 117 to malfunction. For example, if noise is superimposed on the gate terminal g of transistor 117, transistor 117 may turn on and be destroyed. The signal wiring 222 should be twisted wire or use shielded wiring such as coaxial cable.

[0099] As shown in Figure 9, the connector 208 is located on the side of the housing 210, and the connector 208 is connected to the device control circuit board 209 located in chamber B by signal wiring 235. Control signals or output signals from the gate driver circuit 113, gate signal control circuit 112, temperature measurement circuit 115, variable resistor circuit 125, and operational amplifier circuit 116 are input and output from the device control circuit board 209.

[0100] As shown in Figure 2(b), the connecting structure 218a is inserted into the opening 216a. By inserting the connecting structure 218a into the opening 216a, the element terminal 226a of the transistor 117 is sandwiched between the connecting fitting 232 and the connecting fitting portion 233 at the tip of the connecting structure 218a. After connecting the connecting structure 218a and the element terminal 226a, tightening the fixing screw 224b1 enables a good electrical connection between the contact portion 225 and the element terminal 226.

[0101] Similarly, the connecting structure 218b is inserted into the opening 216b. By inserting the connecting structure 218b into the opening 216b, the element terminal 226b of the transistor 117 is sandwiched between the connecting fitting 232 and the connecting fitting portion 233 at the tip of the connecting structure 218b. After connecting the connecting structure 218b and the element terminal 226b, a good electrical connection can be achieved between the contact portion 225 and the element terminal 226 by tightening the fixing screw 224b2.

[0102] A cooling fan 227 is positioned on the back of the connecting structure 218 to remove heat from the heat pipe 223. The rotation speed of the cooling fan 227 is controlled according to the overheating status of the element terminals 226 and the heat pipe 223.

[0103] In the embodiment shown in Figure 3, the heat pipe 223 is attached to the recess 234 of the heat pipe fitting 231 of the connecting structure 218. However, the present invention is not limited to this.

[0104] For example, the connecting structure 218 may be configured as shown in Figure 4. In Figure 4, Figure 4(a) is a simulated illustration of the back surface (bottom surface) of the connecting structure 218, and Figure 4(a) is a simulated illustration of the front surface (top surface) of the connecting structure 218.

[0105] In Figure 4, the heat pipe 223a is positioned on the concave surface 234a. The heat pipe 223a is formed or positioned up to the connecting fitting portion 233. By forming or positioning it up to the connecting fitting portion 233, the heat generated at the element terminal 226 can be transferred more efficiently.

[0106] As shown in Figure 4(b), the heat pipe 223b is positioned on the concave surface 234b. By positioning the heat pipe 223 on both sides of the connecting structure 218, the heat generated at the element terminal 226 can be transferred more efficiently.

[0107] The embodiment shown in Figure 3 uses a cooling fan 227 to cool the heat pipe 223, but the present invention is not limited to this. For example, as shown in Figure 5, heat dissipation fins 228 may be formed or arranged so as to be in close contact with the heat pipe 223. The heat transferred within the heat pipe 223 is efficiently transferred to the heat dissipation fins 228, further enhancing the heat transfer and heat dissipation effects of the heat pipe 223.

[0108] In Figure 5, the heat dissipation fins 228 are not formed or positioned in the area corresponding to the opening 216. The connecting structure 218 is inserted from the C2 chamber to the C1 chamber through the opening 216. To maintain the airtightness of the C1 chamber, the opening 216 is sized to be the cross-sectional area of ​​the connecting structure 218 + α. Therefore, if the heat dissipation fins 228 were formed or positioned on the connecting structure 218, it would not be possible to insert it into the opening 216. For this reason, the heat dissipation fins 228 are not formed or positioned on the side connected to the element terminal 226 of the transistor 117 with respect to the partition wall 217.

[0109] Furthermore, as shown in Figure 6, a circulating water pipe 135 may be formed or arranged within the connecting structure 218 to cool the connecting structure 218. The refrigerant flowing through the circulating water pipe cools the connecting structure 218, and the heat transfer within the heat pipe 223 is efficiently transmitted to the connecting structure 218. Therefore, the heat generated at the element terminal 226 is efficiently dissipated.

[0110] The transistor 117 (semiconductor element 117) in Figure 12 had two element terminals 226, element terminal 226a (P) and element terminal 226b (N). However, as shown in Figure 13, some transistors 117 have three element terminals 226, consisting of element terminal 226a (P), element terminal 226b (N), and element terminal 226c. The semiconductor element testing apparatus and semiconductor element testing method of the present invention can test a wide variety of semiconductor elements 117.

[0111] The semiconductor device 117 in Figure 13 consists of two transistors, transistor 117m and transistor 117s, arranged in a single package. The collector terminal c of transistor 117s is connected to device terminal 226a. The emitter terminal e of transistor 117s is connected to the collector terminal c of transistor 117m, and the midpoint is connected to device terminal 226c. The emitter terminal e of transistor 117m is connected to device terminal 226b.

[0112] Transistor 117m has emitter terminal e1, gate terminal g1, and collector terminal c1 connected to it. Transistor 117s has emitter terminal e2, gate terminal g2, and collector terminal c2 connected to it.

[0113] Figure 7 is an explanatory diagram illustrating the connection state between a transistor 117 (semiconductor element 117) having three element terminals 226 (element terminal 226a (P), element terminal 226b (N), and element terminal 226c (O)) and a connecting structure 218.

[0114] In Figure 7, the connection between the connection structure 218a and the element terminal 226a, and the connection between the connection structure 218b and the element terminal 226b are the same as those described in Figures 1 and 2, so their explanation is omitted.

[0115] In Figure 7, a heat pipe 223a is formed or arranged on the connection structure 218a, and a heat pipe 223b is formed or arranged on the connection structure 218b, whereas a heat pipe 223 is not formed or arranged on the connection structure 218c. The connection structure 218c is connected to the element terminal 226c. No large current flows through the element terminal 226c(O) of the transistor 117. Therefore, the element terminal 226c is not overheated. There is no need to form a heat pipe 223 on the connection structure 218c. By forming the connection structure 218c thinner than the other connection structures 218 (connection structures 218a and 218b), the connection between the connection structure 218 and the element terminal 226 of the transistor 117 becomes easier. Also, since the space for arranging the transistor 117 is narrower, the number of transistors 117 that can be mounted on the heating / cooling plate 134 can be increased.

[0116] It goes without saying that a heat pipe 223 may be formed or arranged on the connecting structure 218c. Other matters are the same as or similar to the embodiments in Figures 1 and 2, so their explanation will be omitted.

[0117] In the embodiment shown in Figure 15, the element terminal 226 is sandwiched between contact portions 225a and 225b to establish an electrical connection. The current supplied to the element terminal 226 of the transistor 117 mainly flows through the connecting fitting portion 233, but there is also current flowing from the connecting fitting 232 to the element terminal 226. The current flowing through the connecting fitting 232 flows from the fixing screw 224b -> connecting fitting 232 -> contact part 225b -> element terminal 226. The current flowing through the element terminal 226 can be as large as several hundred amperes, and if the connection resistance is high at the fixing screw 224b or other points, it will generate heat and the heat-generating part may burn out.

[0118] In this specification and in the drawings, the connecting fitting 232 is depicted as a conductive fitting, but it is not required that the connecting fitting 232 be made of a conductive metal. Needless to say, it may be made of resin material or the like. Figure 16 is an explanatory diagram illustrating the connection method and connection structure between the connection structure 218 and the element terminal 226 in another embodiment of the present invention.

[0119] The element terminal 226 is sandwiched between the pressing tool mounting plate 313 and the connecting fitting portion 233. Pressing tools 311a and 311b are attached to the pressing tool mounting plate 313. The pressing tool 311 is exemplified by a metal leaf spring. The pressing tool 311 may also be made of a non-conductive material such as a silicone resin material. The pressing tool 311 is fitted into the pressing tool mounting plate 313. It is preferable that the surface of the pressing tool 311 be roughened so that it can properly press the element terminal 226.

[0120] The element terminal 226 is held between the planes of the pressing tool 311 and the connecting fitting portion 233. The pressing of the pressing tool 311 electrically connects the element terminal 226 and the connecting fitting portion 233. The pressing tool 311 is not required to be conductive.

[0121] The connecting fitting portion 233 is preferably integrated with the heat pipe fitting 231. The connecting fitting 232 is fixed to the connecting fitting portion 233 with fixing screws 224b. The element terminals 226 of the semiconductor element are fixed by tightening or positioning the fixing screws 224b. The connecting wiring 211 is fixed to the left end of the heat pipe fitting 231 with fixing screws 221. The connecting fitting portion 233 is connected to and fixed to the connecting fitting 232 by screws 224b inserted into screw holes 238b1 and 238b2.

[0122] Screw 224 is exemplified by metal materials such as phosphor bronze and stainless steel, but is not limited to these. It may also be made of non-conductive materials such as resin. In addition, it may be made of a cushioning material such as sponge.

[0123] The pressing tool mounting plate 313 has protrusions 251 formed at both ends, and the connecting fitting 232 has grooves 252 formed at both ends. The protrusions 251 of the pressing tool mounting plate 313 are fitted into the grooves 252 of the connecting fitting 232. The protrusions 251 of the pressing tool mounting plate 313 and the grooves 252 of the connecting fitting 232 are configured to make electrical contact.

[0124] Figure 18 is an explanatory diagram and configuration diagram of the pressing mounting plate 313 shown in Figure 16. Figure 18(a) is a side view of the pressing mounting plate 313, and Figure 18(b) is a bottom view of the pressing mounting plate 313 as seen from the back.

[0125] As shown in Figure 18(b), multiple pressing devices 311a and multiple pressing devices 311b are arranged in a matrix on the back surface of the pressing mounting plate 313. Also, as shown in Figure 18(a), the pressing device 311 is fitted into the pressing mounting plate 313.

[0126] A positioning screw hole 240 is formed in the pressing mounting plate 313, and a positioning fixing screw 237 is inserted into the positioning screw hole 240. In addition, a spring hole 239 is formed in the pressing mounting plate 313, and a spring 236 is inserted into the spring hole 239. In the embodiment shown in Figure 16, the spring (pressure fitting) 236 applies appropriate pressure between the pressing tool 311 and the element terminal 226, maintaining a good electrical connection.

[0127] In the embodiment shown in Figure 16, the spring (pressure fitting) 236 is inserted into the spring hole 239 of the contact portion 225. If the spring (pressure fitting) 236, contact portion 225, and connecting fitting 232 are made of conductive material, electricity may flow from the element terminal 226 -> contact portion 225 -> spring (pressure fitting) 236 -> connecting fitting 232. In this case, if the resistance value of the spring (pressure fitting) 236 is large, current may flow through the spring (pressure fitting) 236, causing the spring to overheat and burn out.

[0128] If the pressing tool 311 is made of a non-conductive material and configured so that no current flows through the pressing tool mounting plate 313, the aforementioned current path will not occur, and the spring (pressure fitting) 236 will not burn out.

[0129] Figure 17 is an explanatory and configuration diagram of a connection structure 218 in another embodiment of the present invention. In the embodiment of the present invention shown in Figure 17, the spring hole 312 is formed in the insulating plate 312. The pressing tool 311 contacts the element terminal 226, and the spring 236 presses against the pressing tool mounting plate 313. The insulating plate 312 is positioned above the pressing tool mounting plate 313 to insulate the pressing tool mounting plate 313 from the spring 236. A spring hole 239 is formed in the insulating plate 312, and the spring 236 is inserted into the spring hole 239.

[0130] As shown in Figure 17, the pressing tool 311 contacts the element terminal 226, and the spring 236 presses against the pressing tool mounting plate 313. An insulating plate 312 is placed above the pressing tool mounting plate 313 to insulate the pressing tool mounting plate 313 from the spring 236. A spring hole 239 is formed in the insulating plate 312, and the spring 236 is inserted into the spring hole 239. The other configurations are the same as in Figure 16, so their explanation is omitted.

[0131] Figure 19 is an explanatory diagram of the press tool mounting plate 313 and insulating plate 312 of the connecting structure 218 in Figure 17. Figure 19(a) is a side view of the press tool mounting plate 313. Figure 19(b) is a side view of the press tool mounting plate 313 as seen from side A in Figure 19(a).

[0132] The pressing tools 311a and 311b are positioned and inserted into the pressing tool mounting plate 313. In the embodiment shown in Figure 19, the insulating plate 312 and the protrusion 251 are made of insulating material, and the spring hole 312 is formed in the insulating plate 312. Therefore, since the spring hole 312 is insulated, no current path is generated in the connecting fitting 232.

[0133] Since the insulating plate 312 is made of an insulating material, no current flows through the spring (pressure fitting) 236, even if the pressure tool mounting plate 313 is made of a conductive material such as metal. Therefore, no current path is generated from element terminal 226 -> contact part 225 -> spring (pressure fitting) 236 -> connecting fitting 232. The insulating plate 312 may be an insulating film, an insulating film, or an insulating gas such as air. Furthermore, the pressing tool mounting plate 313 may be made of a non-conductive material.

[0134] The embodiment shown in Figure 17 was configured to be insulated by an insulating plate 312. The insulating effect in the present invention is not limited to a configuration using an insulating plate 312, as shown in Figure 17. For example, the configuration shown in Figure 20 is an example.

[0135] Figure 20 shows a configuration in which an insulating part 315 made of resin material or the like is placed around the screw hole 238b of the connecting fitting 232. Figure 22 is a configuration view of the connecting fitting 232 of Figure 20 as seen from the back. As shown in Figure 22, the area around the screw hole 238b is surrounded by the insulating part 315, so that the screw can be insulated. Alternatively, a fixing screw 224b made of an insulating material may be used.

[0136] Since the area around the screw hole 238b is insulated by the insulating part 315, no current flows through the fixing screw 224b. Therefore, no current path is generated from element terminal 226 -> contact part 225 -> spring (pressure fitting) 236 -> connecting fitting 232, and the spring (pressure fitting) 236 does not burn out. As described above, the present invention is configured such that an insulating plate 312 is placed on the side of the spring 236 that applies pressure, so that current does not flow to the side of the pressing tool mounting plate 313 and the contact portion 225.

[0137] When current flows, it flows to the pressing components such as the spring 236 and the fixing screw 224b, causing the spring 236 and fixing screw 224b to burn out. Current is supplied to the element terminal 226 via the connecting fitting part 233, which has fewer electrically high-resistance parts such as the spring 236.

[0138] Figures 16, 17, and 20 show embodiments of a connecting structure 218 having a pressing tool 311. The present invention is not limited thereto, and for example, the configuration shown in Figure 21 may also be used.

[0139] Figure 21 shows a configuration in which the element terminal 226 is sandwiched between the contact portion 225 and the connecting fitting portion 233. By roughening the surface of the contact portion 225, uniform pressure can be applied to the element terminal 226. By making the contact portion 225 out of insulating material, it is possible to prevent current paths from being generated in the connecting fitting 232.

[0140] It goes without saying that preventing current from being generated on the side of the connecting fitting 232 can also be achieved by constructing the fixing screw 224b and the connecting fitting 232 from insulating material.

[0141] In the electrical element testing apparatus of the present invention, as illustrated and explained in Figures 1 and 14, a connection is made between one end of the connection structure 218 and the element terminal 226 of the semiconductor element 117 by inserting the connection structure 218 into the opening 216. The present invention is not limited thereto. For example, the configurations shown in Figures 23 and 24 are examples.

[0142] Figure 23 is an explanatory diagram of the connection structure 218 of the electrical element testing apparatus of the present invention, viewed from the front. Figure 24 is an explanatory diagram of the connection structure 218 of the electrical element testing apparatus of the present invention, viewed from above. A cooling fan 227 is positioned on the side, and the heat pipe 223 of the connection structure 218 is cooled by the fan.

[0143] Figure 23 shows the heater / cooler 322 with the top of the paper facing upwards and the bottom of the paper facing downwards. As an example, the heater / cooler 322 has two electrical element insertion holes 324, and the electrical elements 117 are inserted into the electrical element insertion holes 324 in close contact with the heater / cooler 322. The connection structure 218a is connected to the element terminal 226a of the electrical element 117, and the connection structure 218b is connected to the element terminal 226b of the electrical element 117.

[0144] A circulating water pipe 135 is attached to the heating / cooling unit 322. Circulating water flows in from the circulating water pipe 135a, circulates within the heating / cooling unit 322, and is discharged from the circulating water pipe 135b. The circulating water maintains the electrical element 117 at a predetermined temperature.

[0145] The connecting structure 218 is positioned in the slide groove 325 of the support base 323, and the connecting structure 218 is slid along the slide groove 325 so that the connecting fittings 232 and connecting fitting portion 233 of the connecting structure 218 are electrically connected to the element terminal 226.

[0146] Figure 25 illustrates the connection (contact) state between the fork plug 205 and the conductor plate 204. Two conductor plates 204 are attached to the switch circuit board 201. The switch circuit board 201 has a full-surface ground layer (not shown), and the full-surface ground layer and the conductor plates 204 are thermally connected. The heat from the conductor plates 204 is dissipated through the full-surface ground layer. The conductor plates 204 and the switch circuit board 201 are fastened together with screws.

[0147] In this specification and in the drawings, the conductor plate 204 is described, but it is not limited to a plate and may be rod-shaped. Any shape is acceptable as long as it can be joined to a structure such as a fork plug 205. For example, it may be a structure such as a socket or connector. Alternatively, the conductor plate 204 may be shaped like a fork plug, and the fork plug 205 and the fork plug may be connected.

[0148] Furthermore, while the fork plug 205 is described as being inserted into a component or structure that separates a space, such as a partition wall 214, it is not limited to this. For example, the fork plug 205c may be connected to the conductor plate 204b, and the fork plug 205c may be inserted from the partition wall 214 to make an electrical connection with the emitter terminal e of the transistor 117.

[0149] Partitions 214 and 215 can be any form that divides or separates a space or area. A wide variety of configurations or structures are applicable, such as wall-like, plate-like, mesh-like, film-like, foil-like, etc.

[0150] The fork plug 205 may have any configuration, structure, form, type, or method that allows it to be electrically connected to an object such as a conductor plate 204 by press-fitting, pressure-welding, insertion, crimping, clamping, fitting, etc.

[0151] The switch circuit 124 is connected to two conductive plates. As shown in Figure 30, if the switch circuit 124 is a MOS transistor, the drain terminal and source terminal are connected to different conductive plates 204. If the switch circuit 124 is a bipolar transistor, the collector terminal and emitter terminal are connected to different conductive plates 204. When the switch circuit 124 is turned on (conductive), the two conductive plates 204 are electrically connected. An IGBT can also be used as the switch circuit 124.

[0152] The switch circuit 124 is mounted on the switch circuit board 201. The switch circuit 124 is connected to a conductor plate 204 (metal plate, conductive plate). The conductor plate 204 is, for example, a copper plate with a thickness of 5 mm and a width of 50 mm. Its length is the width of the circuit board plus the width required to connect the fork plug 205.

[0153] The fork plug 205 and the conductor plate 204 are electrically connected by mechanical mating. When the U-shaped portion of the fork plug 205 is inserted into the conductor plate 204, the U-shape expands slightly, ensuring a good connection between the fork plug 205 and the conductor plate 204. Due to this good connection or mating, the electrical resistance of the connection is extremely low, and even when a large current flows through the connection, no heat generation or voltage drop occurs.

[0154] A connecting bolt 219 is attached to the fork plug 205. A connecting wire 211 is connected to the connecting bolt 219. A cross-section at AA' in Figure 25(a) is shown in Figure 25(b). The conductor plate 204 and the fork plug 205 are in contact at contact portions 220a and 220b formed on the fork plug 205. The surface of the contact portion 220 is silver-plated. The contact portion 220 is made of phosphor bronze and nickel alloy. Note that the connecting bolt 219 is not limited to a bolt; any type of bolt that can electrically connect the fork plug 205 and the wire is acceptable. The surface of the conductor plate 204 is silver-plated at least in the portion that comes into contact with the fork plug 205.

[0155] Figure 10 is a configuration diagram of the semiconductor device testing apparatus of the present invention. The connecting structure 218a is inserted into the opening 216a of the partition wall 217, and the connecting structure 218b is inserted into the opening 216b of the partition wall 217.

[0156] It goes without saying that, as illustrated and explained in Figures 23 and 24, the connecting structure 218 may also be slid into the sliding groove 325 of the support base 323 to connect it to the element terminal 226 of the semiconductor element 117.

[0157] The connecting structure 218a is connected to the element terminal 226a of the transistor 117, and the connecting structure 218b is connected to the element terminal 226b of the transistor 117. A circulating water pipe 135 is incorporated into the heating and cooling plate 134.

[0158] A connector 202 is connected to the terminals of transistor 117, and a signal wire 222 connected to the connector 202 is connected to the sample connection circuit 203. The signal wire 235 of the sample connection circuit 203 is connected to the device control circuit board 209 via a connector 208.

[0159] As shown in Figure 10, the fork plug 205 and the conductor plate 204 come into contact when the fork plug 205 is inserted through the opening 216 of the partition wall 214. Upon contact, the U-shaped portion of the fork plug 205 is spread open by the conductor plate 204, resulting in a firm contact.

[0160] Figure 9 shows the arrangement of each component of the semiconductor device testing apparatus of the present invention. The housing 210 of the semiconductor device testing apparatus is separated into three parts. The lower part of the housing is separated into chamber A and chamber B. The power supply unit 132 is located in chamber A. Chamber A and chamber B are separated by a partition wall 215.

[0161] Each chamber is shielded. The power supply 132, switch circuit board 201, and transistor 117 generate significant noise through repeated operation and deoperation. Since this noise can cause the circuit board and other components to malfunction, shielding is used to prevent such malfunctions. Shielding is achieved by placing conductive plates, metal plates, or metal films around each chamber.

[0162] Chamber C1 contains the heating and cooling plate 134, circulating water pipe 135, etc., as shown in Figure 8, and the transistor 117 to be tested is placed on the heating and cooling plate 134.

[0163] A partition wall 214 is formed between chamber C1 and chambers A and B. A water leak sensor (not shown) is positioned around the heating and cooling plate in chamber C1. The system is configured to activate the water leak sensor if circulating water (cooling medium) or the like leaks, stopping the semiconductor device testing equipment or issuing an alarm.

[0164] Furthermore, drainage grooves are formed around the heating and cooling plate, so that if circulating water (cooling medium) leaks from the heating and cooling plate, it flows into the drainage grooves and is discharged outside the semiconductor device testing apparatus. As described above, the partition wall 214 is configured to prevent circulating water (cooling medium) from leaking into the lower chambers A and B even if the circulating water pipe 135 is damaged.

[0165] A partition wall 215 is formed between Room A, where the power supply unit 132 is located, and Room B, where the drive circuit system is located. Electrostatic shielding plates are placed on partition walls 214, 215, and 217 to shield noise from the power supply unit 132, preventing the noise from being applied to the drive circuit system in Room B.

[0166] In the embodiments of the present invention, the fork plug 205 is inserted from chamber C2 and connected to the conductor plate 204 in chamber B. Pushing the fork plug 205 in from the top to the bottom is easy. However, the present invention is not limited to this. For example, the conductor plate 204 may be placed in chamber C2, and the fork plug 205 may be inserted from chamber B to make an electrical connection. Furthermore, the connecting structure 218 is inserted from the C2 chamber, connecting the element terminal 226 of the semiconductor element 117 to the connecting structure 218.

[0167] As shown in Figure 9, the connection structure 218 is inserted from chamber C2 to chamber C1 and electrically connected to the element terminal 226 of transistor 117. The fork plug 205 is also inserted from chamber C2 to chamber B, electrically connecting the fork plug 205 to the conductor plate 204. Transistor 117 is fixed to the heating / cooling plate 134, and the switch circuit board 201 is fixed at the position of the mother board 207. The connection structure 218 and the fork plug 205 are electrically connected by connection wiring 211.

[0168] The position of the opening 216 can be selected using the connection structure 218, and the transistor 117 to be tested can be selected. By selecting the opening into which the fork plug 205 is inserted, the control switch circuit board 201 can be easily selected, and the test method and test conditions can be changed. Therefore, by using the connection structure 218 and the fork plug 205, the present invention allows for easy selection of the transistor 117 and quick changes to the test method, etc.

[0169] Partition walls 214, 215, and 217 can be exemplified by wall-like structures, plate-like structures, film-like materials, mesh-like materials, wire mesh-like materials, etc. Phenolic resin (phenol resin, phenol-formaldehyde resin, carbolic acid resin) is one example. The partition wall can be anything that separates the first part and the second part of the semiconductor device testing apparatus.

[0170] As shown in Figure 26, a connector 213 is attached to the motherboard 207. The control circuit board 111, the device control circuit board 209, and the switch circuit board 201 are attached to the connector on the motherboard 207. The number of switch circuit boards 201 to be prepared according to the number of transistors 117 to be tested can be easily changed by changing the number of switch circuit boards 201 attached to the motherboard 207.

[0171] The motherboard 207 receives temperature information Tj, voltage Vi, control signals for the variable resistor circuit 125, and control signals for the constant current circuit 118. Power and ground wiring for each circuit are also formed and supplied to each circuit board via connector 213. The conductor plate 204 is positioned so as to protrude from the switch circuit board 201. The fork plug 205 is connected to this protruding portion.

[0172] The fork plug 205a is connected to the conductor plate 204a of the switch circuit board 201a. The power wiring 212 is connected to the switch circuit board 201a via the opening 216 of the partition wall 215. The fork plug 205d is connected to the conductor plate 204c of the switch circuit board 201b. The power wiring 212 is connected to the switch circuit board 201b via the opening 216 of the partition wall 215. The fork plug 205b is connected to the conductor plate 204b of the switch circuit board 201a. The power wiring 212 is connected to the switch circuit board 201a via the opening 216 of the partition wall 215.

[0173] As shown in Figure 11, etc., a switch circuit 124a is placed between the conductor plates 204d and 204c of the switch circuit board 201b, short-circuiting the space between the conductor plates 204d and 204c. By short-circuiting, the current Ia output by the current power supply circuit 121a is supplied to the transistor 117 as a test current Id.

[0174] A switch circuit 124b is positioned between conductor plates 204a and 204b of the switch circuit board 201a. When the switch circuit 124b is turned on, it short-circuits the conductor plates 204a and 204b. This short-circuit causes the current Ia output by the current power supply circuit 121a to flow to ground as a discharge current Im, short-circuiting the channels of transistor 117. Because the channels are short-circuited, no overvoltage or overcurrent is applied to transistor 117.

[0175] A fork plug 205 is connected to conductor plate 204. A fork plug 205c is connected to conductor plate 204b. A fork plug 205b is connected to conductor plate 204a. A fork plug 205e is connected to conductor plate 204d. A fork plug 205d is connected to conductor plate 204c.

[0176] Figure 25 is a diagram of the fork plug 205. Figure 25(a) shows the state in which the conductor plate 204 attached to the switch circuit board 201 and the fork plug 205 are connected. Figure 25(b) shows the state of connection between the conductor plate 204 and the fork plug 205 when viewed from the direction of the arrow in a cross-section along line AA' in Figure 25(a).

[0177] The fork plug 205 is made of a metal such as aluminum. Its surface is nickel-plated and then silver-plated. The fork plug 205 has a threaded groove, allowing the connecting wire 211 to be attached to it using a connecting bolt 219.

[0178] The convex contact portion 220 is made of phosphor bronze and copper alloy. The surface of the contact portion 220 is also silver-plated. The insertion force of the fork plug 205 into the conductor plate 204 is configured to be between 40 and 60 N.

[0179] Platinum, gold, silver, tungsten, copper, nickel, or alloys combining these materials can be used as the contact portion 220. It is also preferable to use silver oxide contact materials (Ag+ZnO, Ag+SnO2, Ag+SnO2In2O3, Ag+, Ag+SnO2Sn2Bi2O7).

[0180] Figure 26 shows two switch circuit boards 201, but more than two switch circuit boards 201 are required depending on the number of transistors 117 to be tested, and the switch circuit boards 201 are connected to the connector 213 on the motherboard 207.

[0181] As shown in Figure 10, the fork plug 205c is inserted through an opening 216 in the partition wall 214 located between chambers C2 and B, connecting the conductor plate 204b and the fork plug 205c. Chamber C1 contains the transistor 117 to be tested and the heating / cooling plate 134, while chamber B contains the drive circuit and other components for testing the transistor 117. Since chambers C1, C2, and B are separated by the partition wall 214, even if refrigerant leaks from the heating / cooling plate 134, it will not leak into chamber B. A water leak sensor (not shown) is placed around the heating / cooling plate 134. In addition, a groove is formed to discharge the refrigerant outside the test apparatus if it leaks out. A static shield plate is placed on the partition wall 214 to prevent the drive circuit system of chamber B from malfunctioning due to noise generated by the transistor 117.

[0182] Because the current flowing through the transistor 117 being tested is large, several hundred amperes, the connecting wires 211 used are also thick. As a result, the connecting wires 211 lack flexibility and are rigid, making it difficult to change their connections.

[0183] In the semiconductor device testing apparatus of the present invention, the switch circuit board 201 can be connected via a fork plug 205 inserted from the C2 chamber. Therefore, changing the connection to the switch circuit board 201 used depending on the test conditions of the transistor 117 does not require changing the wiring of the connection wiring 211, and only the position of the opening 216 into which the fork plug 205 is inserted needs to be changed. Furthermore, the switch circuit board 201 only requires changing the position of the connector 213 that connects to the motherboard 207.

[0184] As shown in Figures 9, 11, 29, and 30, the connecting wire 211b connected to transistor 117 is connected to fork plug 205c. The connecting wire 211a connected to transistor 117 is connected to fork plug 205e.

[0185] Even if there are multiple transistors 117 being tested, the application is still satisfactory even if there is only one switch circuit board 201a. This is because the output current Ia of the current power supply circuit 121a can be passed to the ground line as Im.

[0186] The switch circuit board 201b requires the same number of transistors 117 to be tested. For example, if there are 12 transistors 117 to be tested, it is preferable to prepare 12 switch circuit boards 201b. It is also cost-effective to make the switch circuit boards 201a and 201b the same specifications.

[0187] Multiple transistors and other components are mounted on the switch circuit board 201 as switch circuits 124. The more switch circuits 124 there are, the smaller the impedance that short-circuits the two conductor boards 204. The number of switch circuits 124b mounted on the switch circuit board 201a is determined so that the on-resistance of each switch circuit 124b is smaller than the on-resistance of the transistor 117 being tested.

[0188] Figures 27 and 28 illustrate the state in which the fork plug 205 is inserted into the opening 216 of the bulkhead 214. Figure 27 is a view of the bulkhead 214 from the front surface, and Figure 28 is a view of the bulkhead 214 from the back surface.

[0189] As an example, the conductor plate 204b in Figure 27 is connected to a fork plug 205b and several fork plugs 205c (fork plugs 205c1 to 205c5). The conductor plate 204d1 is connected to fork plug 205e1, the conductor plate 204d2 to fork plug 205e2, the conductor plate 204d3 to fork plug 205e3, the conductor plate 204d4 to fork plug 205e4, and the conductor plate 204d5 to fork plug 205e5.

[0190] A transistor 117 to be tested is connected between fork plug 205c and fork plug 205e. A number of switch circuit boards 201b equal to the number of transistors 117 to be tested are mounted on the mother board 207. The opening 216 is formed corresponding to the position of the conductor plate 204 on the switch circuit board 201.

[0191] Although not shown in the diagram, significant noise is generated when the switch circuit 124 on the switch circuit board 201 is switched on and off. To counteract this, a metal plate is placed between the switch circuit boards 201 and the metal plate is grounded.

[0192] In each drawing, one switch circuit 124 is shown on the switch circuit board 201. However, in reality, multiple switch circuits 124 are arranged between the conductor plates 204. By arranging multiple switch circuits 124 on the switch circuit board 201, it is possible to short-circuit between the conductor plates 204 (for example, between conductor plate 204c and conductor plate 204e) with low resistance.

[0193] The heat generated by the switch circuit 124 is dissipated to the conductor plate 204. Additionally, a heat sink is attached to the switch circuit 124. The ground terminal of the switch circuit 124 is connected to the ground of the switch circuit board 201, and heat is also dissipated through the copper foil of the ground.

[0194] As shown in Figure 9, two conductive plates 204 are attached to the switch circuit board 201, and the switch circuit 124 is arranged to short-circuit the two conductive plates 204. Figure 29 is an equivalent circuit diagram of the semiconductor device testing apparatus of the present invention in the first embodiment.

[0195] As shown in Figures 9, 10, and 11, a conductor plate 204a and a conductor plate 204b are attached to the switch circuit board 201a. Conductor plate 204a is connected to a fork plug 205a. The fork plug 205a is connected to the output terminal of the current power supply circuit 121a. Conductor plate 204b is connected to a fork plug 205b. The fork plug 205b is connected to the ground terminal of the current power supply circuit 121a.

[0196] When switch circuit 124b is turned on, the output terminals of the current power supply circuit 121a are short-circuited, and a short-circuit current Im flows. Therefore, the output current of the current power supply circuit 121a is not supplied to transistor 117. When switch circuit 124b is open, the output current Ia of the current power supply circuit 121a is supplied to transistor 117.

[0197] Conductor plates 204c and 204d are attached to the switch circuit board 201b. Conductor plate 204c is connected to fork plug 205d. Fork plug 205d is connected to the output terminal of the current power supply circuit 121a. Conductor plate 204d is connected to fork plug 205e. Fork plug 205e is connected to the collector terminal of transistor 117 to be tested.

[0198] As shown in Figures 9, 10, 27, and 28, the fork plug 205e is inserted into the opening 216 in the bulkhead 214 and connected to the conductor plate 204d. Similarly, the fork plug 205c is inserted into the opening 216 in the bulkhead 214 and connected to the conductor plate 204d.

[0199] A switch circuit 124a is placed on the switch circuit board 201b. When the switch circuit 124a is turned on, the output current Ia from the current power supply circuit 121a is supplied to the transistor 117 as a test current Id.

[0200] The switch circuit board 201b is located in compartment B of the enclosure 210, and the transistor 117 to be tested is electrically connected to the switch circuit board 201b by a fork plug 205 inserted from compartment C2 through an opening 216 in the partition wall 214.

[0201] As illustrated in Figures 9, 10, 27, and 28, the fork plug 205 and the conductor plate 204 are connected. In Figure 10, the switch circuit boards 201 are shown as being arranged in parallel. In reality, the switch circuit boards 201 are inserted and arranged in parallel in the board rack. A motherboard is located on the side of the board rack, and control signals to each circuit board are applied from the motherboard. The following describes the test method for the semiconductor device of the present invention. Figures 29, 30, and 31 are explanatory diagrams of the test method for the semiconductor device of the present invention in the first embodiment.

[0202] The constant current circuit 118 supplies a constant current Ic to the diode Di of transistor 117. The operational amplifier circuit 116 buffers and outputs the terminal voltage Vi of diode Di. The terminal voltage Vi is applied to the temperature measurement circuit 115, which obtains the temperature information Tj of transistor 117 from the terminal voltage Vi and transmits it to the controller 111. The temperature information is output from the connector 213 of the device control circuit board 209 to the mother board 207 and sent to the control circuit board 111 (see Figure 26, etc.).

[0203] The gate driver circuit 113 outputs an on-voltage Vg that turns on the gate of transistor 117 at a set frequency and a set on-voltage time. As an example, as shown in Figure 31(a), the on-off period of transistor 117 is tcycle, the on-time is ton, and the off-time is tooff.

[0204] The transistor 117 is switched on and off based on the ON signal voltage Vgs in Figure 31(a). The gate driver circuit 113 is controlled by the gate signal control circuit 112. The current power supply circuit 121a outputs a constant current Ia, which is supplied as Id to transistor 117.

[0205] The Vgs signal voltage output from the gate driver circuit 113 causes transistor 117 to switch on and off, and a current Id flows between the channels of transistor 117 during the period when transistor 117 is on.

[0206] The gate driver circuit 113 has a variable resistor circuit 125 inside. The value of the variable resistor circuit 125 is configured to be set to a predetermined value or in steps between 0 (Ω) and 500 (Ω). The value of the variable resistor circuit 125 may be set by a control signal from the control circuit board (controller) 111 while observing the waveform of the gate terminal g.

[0207] A resistor R (not shown) may be placed between the gate terminal g and the emitter terminal e or collector terminal c of transistor 117. By adjusting the value of resistor R, the slope angle of the rising and falling voltage waveforms of the gate signal can be adjusted.

[0208] When the value of the variable resistor circuit 125 is large, the slope of the rising / falling waveform of the gate signal of transistor 117 applied to the gate terminal of transistor 117 becomes gentler.

[0209] On the other hand, if the resistance value of the variable resistor circuit 125 is small, the slope of the rising / falling waveform of the gate signal becomes steeper. By changing the value of the variable resistor circuit 125 or setting it to a predetermined value, the on-time of the transistor 117 can be adjusted.

[0210] The gate driver circuit 113 can set the slope of the rising waveform (rising time Tr) and the slope of the falling waveform (falling time Td) for the gate voltage applied to the gate terminal g of transistor 117. By adjusting the rising time Tr and the falling time Td separately, the on-time of transistor 117 can be arbitrarily adjusted.

[0211] The resistance value of the variable resistor circuit 125 is set by the control circuit board (controller) 111. The setting is not limited to a constant value. The slope of the rising waveform (rising time Tr) and the falling waveform (falling time Td) of the gate driver circuit 113 may be changed. The resistance value at the rising and falling of the gate signal may also be changed. Furthermore, the resistance value may be controlled in real time. By controlling the variable resistor circuit 125, the on-time of the transistor 117 is stabilized.

[0212] If the resistance value at the rising edge of the gate signal is reduced, the waveform of the on-voltage applied to the gate terminal of transistor 117 becomes steeper, causing transistor 117 to turn on quickly. If the resistance value at the rising edge of the gate signal is increased, the waveform of the on-voltage applied to the gate terminal of transistor 117 becomes gentler, causing transistor 117 to turn on more gradually.

[0213] If the resistance value at the falling edge of the gate signal is reduced, the waveform of the on-voltage applied to the gate terminal of transistor 117 becomes steeper, causing transistor 117 to turn off quickly. If the resistance value at the falling edge of the gate signal is increased, the waveform of the on-voltage applied to the gate terminal of transistor 117 becomes gentler, causing transistor 117 to turn off more gradually.

[0214] As described above, the value of the variable resistor circuit connected to the gate terminal of transistor 117, or the rise time / fall time of the gate driver circuit 113, can be controlled, adjusted, or set. Therefore, as a function of the gate driver circuit 113, the inrush current Is and surge voltage Vs generated in transistor 117 can be changed or modified.

[0215] It goes without saying that the operation of transistor 117 can not only control the on-voltage of the gate terminal of transistor 117, but also change or set the value of the constant current Id or voltage Vm supplied to transistor 117 by the current power supply circuit 121.

[0216] The variable resistor circuit 125 of the gate driver circuit 113 is controlled by the control circuit board (controller) 111. The period time tcycle, on time ton, or off time toff of the gate signal output by the gate driver circuit 113 shown in Figure 31 is controlled by the gate signal control circuit 112, and the gate signal is applied to the gate terminal of transistor 117. The gate signal control circuit 112 is also controlled by the control circuit board (controller) 111.

[0217] In Figures 11, 29, and 30, the resistance value of the variable resistor circuit 125 of the gate driver circuit 113 is shown as variable, but this is not the only option. For example, the variable resistor circuit 125 could be an external resistor, and the resistor could be connected to the gate terminal of the transistor 117 using a connector (not shown), etc. The value of the connected resistor is determined by observing the waveform at the gate terminal of transistor 117 and the waveform of the channel current Id.

[0218] In Figures 11, 29, and 30, a constant current circuit 118 is connected between the collector terminal c and the emitter terminal e of transistor 117. The constant current circuit 118 supplies a predetermined constant current Ic. This constant current Ic is used to monitor the temperature of transistor 117.

[0219] For the purposes of this specification, an IGBT is used as an example, so the terminals of transistor 117 are the gate terminal g, the collector terminal c, and the emitter terminal e. In the case of a MOS transistor 117, the terminals of transistor 117 are the gate terminal g, the drain terminal d, and the source terminal s.

[0220] A body diode or channel diode Di is formed on transistor 117. Note that diode Di may be a diode from another semiconductor chip mounted on the semiconductor chip on which transistor 117 is formed.

[0221] Diode Di may utilize a diode (parasitic diode) that is formed incidentally during the formation of transistor 117. The parasitic diode is formed incidentally due to the layer structure of transistor 117. Structurally, diode Di is formed near the channel portion of transistor 117.

[0222] Diode Di can be any element that does not operate when transistor 117 is running. For example, it is not limited to a diode; a transistor can also be used in diode connection.

[0223] Furthermore, the method is not limited to semiconductors such as diodes; devices such as resistors may also be used. By applying a constant current Ic to a device such as a resistor, the terminal voltage of the resistor is measured. This voltage is measured as voltage Vi.

[0224] As described above, the element used to acquire temperature can be not only semiconductor devices but also resistors and other devices. In other words, any device that can acquire a voltage value by passing an electric current through it, or a device that can acquire a current value by applying a voltage to it, can be used.

[0225] The resistance of diode Di changes due to the heat generated by transistor 117. When a constant current Ic is passed through diode Di, the voltage across the terminals of diode Di changes in proportion to the change in its resistance. By monitoring or measuring the voltage across the terminals, the temperature of transistor 117, or the change in temperature, can be determined. To monitor the temperature of transistor 117 from the voltage of diode Di, it is necessary to obtain the temperature coefficient beforehand.

[0226] The temperature coefficient is determined by setting the transistor 117 to a predetermined temperature in a constant temperature bath, passing a constant current Ic through the diode Di, and measuring the terminal voltage of the diode Di. By changing the predetermined temperature and measuring the terminal voltage of the diode Di, the terminal voltage of the diode as a function of temperature can be obtained. Therefore, the temperature coefficient K of the transistor 117 can be determined from the terminal voltage of the diode Di as a function of temperature.

[0227] The temperature coefficient K may vary between different production lots of transistor 117, but generally it exhibits a constant value across production lots. Therefore, by sampling a transistor 117 from each production lot and determining its temperature coefficient K, this value can be used for other transistors 117.

[0228] To obtain the temperature coefficient K accurately, the temperature coefficient K of each transistor 117 should be measured and tested individually, even within the same lot. The measurement of the temperature coefficient K is not limited to the use of a constant temperature chamber. For example, the temperature coefficient K can be obtained by changing the temperature of the water flowing through the heatsink on which the transistor 117 is mounted.

[0229] During testing, a test current Id is intermittently applied to transistor 117. Immediately after the test current Id is turned off, or after a predetermined short period of time has elapsed, a constant current Ic for temperature measurement is supplied from constant current circuit 118.

[0230] To prevent transistor 117 from overheating due to the constant current Ic, or to ensure that the constant current Ic has no effect, the constant current Ic is set to a value that is sufficiently smaller than the constant current Id flowing through the channel of transistor 117. The constant current Id is set to a current that does not generate enough heat to affect temperature measurement.

[0231] Specifically, the constant current Ic is set to 1 / 1000 or less of the current Id that flows through transistor 117 during testing. Preferably, the current Ic that flows through transistor 117 is between 1 × 10⁶ and 1 × 10⁴ of the current Id. The constant current Ic is set to 0.1 mA or more and 100 mA or less.

[0232] The channel current Id is varied, and the diode voltage Di (the voltage between the collector and emitter terminals of transistor 117) is measured to determine the temperature coefficient K. The determined temperature coefficient K is stored in the temperature measurement circuit 115.

[0233] When measuring temperature, if the diode Di is formed on the same chip as the transistor 117, the saturation voltage Vn may change depending on the gate voltage Vgs. It is preferable that the gate voltage Vgs be zero (0) or a negative voltage.

[0234] As shown in Figure 8, based on the temperature information Tj, the control circuit board (controller) 111 controls the chiller 136. The chiller 136 adjusts the temperature of the circulating water (circulating solution) and adjusts the temperature of the heating and cooling plate 134.

[0235] In the embodiments described above, the temperature coefficient K was determined in advance, but the semiconductor testing method of the present invention is not limited to this. The temperature information Tj of transistor 117 is determined from the temperature coefficient and the diode terminal voltage, etc. The transistor 117 is positioned in close contact with the heating / cooling plate 134, and the temperature of the heating / cooling plate 134 is configured to be approximately the same as that of the transistor 117.

[0236] The control circuit board (controller) 111 controls the chiller 136 to set the temperature of the heating and cooling plate 134 to a predetermined temperature, applies a constant current Ic to the transistor 117, and measures the terminal voltage of the diode Di.

[0237] The temperature coefficient K is determined from the measurement results. The temperature of the heating / cooling plate 134 is set to multiple temperatures, and the temperature coefficient K is determined at each temperature to improve the accuracy of the temperature coefficient value.

[0238] The temperature coefficient K is determined by heating the transistor 117 to a predetermined temperature using the heating and cooling plate 134, passing a constant current Ic through the diode Di, and measuring the terminal voltage. By changing the predetermined temperature and measuring the terminal voltage of the diode Di, the terminal voltage of the diode Di as a function of temperature can be obtained. Therefore, the temperature coefficient K of the transistor 117 can be determined from the terminal voltage of the diode Di as a function of temperature.

[0239] During testing of transistor 117, the constant current Ic is applied to diode Di when the channel current Id is not flowing. In other words, when transistor 117 is not turned on, the constant current Ic is applied and the terminal voltage of diode Di is measured.

[0240] The operational amplifier circuit (buffer circuit) 116 outputs the terminal voltage Vi (terminal c - terminal e) of the diode Di. Note that the operational amplifier circuit 116 is not limited to being composed of operational amplifier elements. Any circuit with high input impedance and low output impedance will suffice. The temperature measurement circuit 115 obtains the temperature information Tj of the transistor 117 being tested from the stored temperature coefficient K and voltage Vi.

[0241] The requested temperature information Tj is sent to the control circuit board (controller) 111. When the temperature information Tj exceeds a predetermined set value, the control circuit board (controller) 111 determines that the transistor 117 is in a predetermined stress state or a degraded state, and takes action such as changing the test control or stopping the test.

[0242] In testing, the main area where transistors degrade is often the junction within transistor 117. The semiconductor itself does not degrade; rather, the junction (bonding, die bond, etc.) of transistor 117 deteriorates, increasing the resistance of the junction. This increased resistance leads to a higher voltage Vce, causing heat generation and raising the temperature of transistor 117.

[0243] When a semiconductor degrades, it is often due to the degradation of the gate oxide (insulating film) of transistor 117. When the gate oxide degrades, a short circuit occurs in the oxide (insulating film), and the voltage Vce decreases. Alternatively, transistor 117 turns off, no current flows through transistor 117, and the voltage Vce rises to the maximum value of the power supply voltage.

[0244] The temperature information Tj initially fluctuates between the lowest temperature T1 and the highest temperature T2 at the start of the test. When the test stresses transistor 117, the Vce voltage of transistor 117 changes, and the temperature information Tj usually changes in the direction of increasing. Therefore, as shown in Figure 32(c), the lowest temperature rises above temperature T1, and the highest temperature approaches the temperature information Tm(Tjmax). In the semiconductor testing method of the present invention, the test is terminated under one of the following conditions. • If the temperature information Tj falls outside the specified range. • If the channel voltage Vce falls outside the specified voltage range. • When the thermal resistance falls outside the specified range.

[0245] In the embodiments shown in Figures 11, 29, and 30, the switch circuits Ssa124a and Sab124b use the symbol for a switch circuit. Any element can be used as a switch circuit for switch circuits Ssa124a and Sab124b as long as it has a small resistance when closed (on) (on resistance). Examples include transistors, mechanical relays, phototransistors, and photodiode switches.

[0246] Figure 30 is an equivalent circuit diagram of a semiconductor device test apparatus in the first embodiment of the present invention. In this embodiment, the switch circuits Ssa and Sab use power MOSFETs 124 as shown in Figure 30. Power MOSFETs have a small voltage between channels (Vsd).

[0247] Furthermore, a switch circuit other than a power MOSFET may be used. It goes without saying that switch circuits Ssa and Sab can be power transistors, etc., not just power MOSFETs. Other examples include electromagnetic relays and electromagnetic switches.

[0248] The channel voltage (Vsdb) of power MOSFET 124b when it is ON is selected to be less than or equal to the channel voltage (Vsda) of power MOSFET 124a when it is ON. In other words, the channel voltage (Vsdb) of power MOSFET 124b when it is ON is made smaller than the channel voltage (Vsda) of power MOSFET 124a when it is ON. This is to ensure that when the switch circuit 124b is ON, the terminals of the current power supply circuit 121a are completely short-circuited, allowing the current Im to flow stably. The above points also apply when the switch circuit 124 is a power transistor or the like. In the case of a power transistor 124, the channel voltage is Vce. When the switch circuit 124a is turned on, the current Ia output by the current power supply circuit 121a can be supplied to the transistor 117 as the test current Id.

[0249] Figure 31 is an explanatory diagram of the test method for the semiconductor device of the present invention in the first embodiment. In Figure 31, Vgs is the gate signal applied to the gate terminal of the transistor 117 to be tested. Id is the current that flows through the transistor 117 during the test. For the sake of simplicity, it is assumed that a constant current Ia flows when the transistor 117 is ON.

[0250] Figure 31(c) shows that St1 is a timing signal that causes current Ic to flow through diode Di. When St1 is at a high level, current flows through diode Di of transistor 117. The operational amplifier circuit 116 acquires the terminal voltage of diode Di, and the temperature measurement circuit 115 converts the terminal voltage into temperature information Tj. The temperature information Tj is sent to the control circuit board (controller) 111, which then performs a test of transistor 117 (semiconductor element 117) according to the temperature information Tj.

[0251] Id is the current flowing through the transistor 117 for which the test is to be conducted, and is the current output by the current power supply circuit 121. St1 and St2 are the time for flowing the measurement current through the diodes for temperature measurement or the measurement time of the temperature. In FIG. 31(e), Ssa is the on / off signal of the switch circuit 124a, and in FIG. 31(f), Sab is the on / off signal of the switch circuit 124b.

[0252] In FIG. 31(g), Vce is the voltage at the c terminal of the transistor 117 (channel voltage of the transistor 117), and the temperature information Tj indicates the measured temperature change of the transistor 117.

[0253] As shown in FIG. 31(a), a gate signal Vgs is applied from the gate driver circuit 113 to the gate terminal g of the transistor 117. The gate signal Vgs has a period time tcycle and an on time ton. The period time tcycle and the on time ton can be set to arbitrary values by the gate signal control circuit 112. Also, the on voltage Vg can be set to an arbitrary voltage.

[0254] In FIG. 31(d), St2 is the timing signal for flowing the current Ic through the diodes Dsa and Dsb in the embodiment shown in FIG. 34. When St2 is at the H level, a current flows through the diode Dsa or Dsb of the transistor 117. This is the case of obtaining the temperature information Tj by flowing a constant current Ic through a device (diode) independent of the transistor 117.

[0255] The operational amplifier circuit 116 acquires the voltage between the terminals of the diode Dsa or Dsb, and the temperature measurement circuit 115 converts the voltage between the terminals into the temperature information Tj. The temperature information Tj is sent to the control circuit board (controller) 111, and the control circuit board (controller) 111 conducts a test on the transistor 117 based on the temperature information Tj. Matters related to St2 will be described in FIG. 34 and the like.

[0256] For ease of understanding, the measured temperature information Tj is described as changing between T1 and T2 as shown in FIG. 31(h). The temperature information Tj increases when the transistor 117 is energized and decreases when the energizing current stops. Also, the temperature information Tj changes with the characteristic change of the transistor 117.

[0257] FIG. 31(e) Ssa shows the timing of the on / off control signal of the switch circuit Ssa. When Ssa becomes Von, the switch circuit Ssa closes (turns on). In the case of 0, the switch circuit Ssa opens (turns off), and the application of current or voltage is interrupted.

[0258] FIG. 31(f) Ssb shows the timing of the on / off control signal of the switch circuit Ssb. When Ssb becomes Von, the switch circuit Ssb closes (turns on). In the case of 0, the switch circuit Ssb opens (turns off).

[0259] FIG. 31(g) Vce is the channel voltage of the transistor 117 (the voltage between the emitter terminal and the collector terminal). When the transistor 117 turns on and off, a surge voltage and a surge current are generated, and the Vce waveform changes complexly over time with the change in the on-resistance of the transistor 117. Also, when a current Ic flows through the diode Di, the Vce waveform of the transistor 117 changes.

[0260] In this specification and the drawings, for ease of explanation or for ease of drawing, it is assumed that the voltage is Vn when the transistor 117 is on and the voltage is Ve when the transistor is off for the explanation. The gate signal is applied to the gate terminal of the transistor 117 to be tested with a period tcycle, an on-time ton, and an off-time toff.

[0261] When the transistor 117 is an N-channel, the gate signal Vgs has a ground (zero) voltage of 0 (V) as the off-voltage and Vg as the on-voltage. When the transistor 117 is a P-channel, the potentials of the on-voltage and the off-voltage are changed.

[0262] During the tn2 period before transistor 117 is turned on, the Vt voltage is set to a negative value than the off voltage. Also, during the tn1 period after transistor 117 is turned off, the Vt voltage is set to a negative value than the off voltage. The Vt voltage is a voltage lower than 0(V) and higher than -4(V). Therefore, Vt is a voltage that is greater than or equal to -4(V) and lower than 0(V).

[0263] Furthermore, if transistor 117 is SiC, the off-voltage is set to the Vt voltage, and if it is an IGBT, the off-voltage is set to 0 (V). As described above, the semiconductor device testing apparatus of the present invention is configured so that the off-voltage supplied to transistor 117 can be changed according to the type of transistor 117 being tested.

[0264] When the Vt voltage is applied, the temperature of transistor 117 is measured by setting St1 (St2) to a high level. A constant current Ic is passed through diode Di during the period when the Vt voltage is applied. Also, a constant current Ic is passed through St1 (St2) during the period when it is at a high level.

[0265] By applying the Vt voltage to the gate terminal of transistor 117, the off state of transistor 117 is stabilized, enabling stable measurement of temperature information Tj. Furthermore, noise is less likely to be introduced during the measurement of temperature information Tj, improving the measurement accuracy of temperature information Tj.

[0266] By applying the Vt voltage to the gate terminal of transistor 117, the leakage current of transistor 117 is reduced, improving the accuracy and stability of the Vi voltage measurement.

[0267] The gate signal Vgs is set to the Vt voltage during the time intervals of tn1 and tn2. For example, the time intervals of tn1 and tn2 are between 0.2ms and 2ms. Transistor 117 is turned off at 0(V).

[0268] Therefore, three voltages, Vg, 0(V), and Vt, are applied to the gate terminal g of transistor 117. During the period when Vt is applied, current is passed through the transistor's diode Di to measure the temperature information Tj.

[0269] When a constant current Ic is applied to the diode Di, the switch circuit Ssa is turned off to control the current from the current power supply circuit 121a so that it is not applied to the transistor 117.

[0270] By applying a constant current Ic to diode Di, the terminal voltage of diode Di is obtained, and the operational amplifier circuit 116 outputs a voltage Vi corresponding to the terminal voltage. The voltage Vi is input to the temperature measurement circuit 115, which then determines the temperature information Tj corresponding to the temperature of transistor 117.

[0271] The temperature information Tj is transmitted to the control circuit board (controller) 111, and the control circuit board (controller) 111 controls the test of the transistor 117 (semiconductor element 117) based on the temperature information Tj, such as continuing, stopping, or changing the test conditions of the transistor 117.

[0272] Figure 31(e) Ssa is the timing signal that controls the on / off state of switch circuit 124a. Figure 31(f) Ssb is the timing signal that controls the on / off state of switch circuit 124b.

[0273] The switch circuit 124a turns on after a delay of tm2 time, following the Vgs signal of transistor 117 becoming Vg. The tm2 time can be changed and set by the control circuit board (controller) 111.

[0274] Switch circuit 124b turns on tb2 hours before switch circuit 124a turns on. Switch circuit 124b remains in the ON state for tb1 hours after switch circuit 124a turns on. tb2 hours and tb1 hours can be changed independently. In particular, the setting of tb1 is important. Observe the waveform of the Vce voltage of transistor 117 and set or change it appropriately.

[0275] Switch circuit 124a turns off tm1 time before the Vgs signal of transistor 117 reaches Vt. The tm1 time is configured to be changeable by control circuit board (controller) 111.

[0276] Switch circuit 124b turns on ta2 time before switch circuit 124a turns off. The on state of switch circuit 124b is maintained until ta1 time after switch circuit 124a turns off. The ta2 time and ta1 time are configured to be independently changeable. In particular, the setting of ta1 is important. Observe or measure the waveform of the Vce voltage of transistor 117 and set or change it appropriately.

[0277] When switch circuit Ssb turns on, the output terminal of current supply circuit 121a is short-circuited to the ground (ground line) and the charge is discharged. When the charge is discharged, the terminal voltage of current supply circuit 121a becomes 0 V (ground voltage). Also, the current Ia output by current supply circuit 121a is made to flow to the ground (ground) as current Im. Therefore, current Ia is not applied to transistor 117 and the collector voltage of transistor 117 does not increase.

[0278] The tb2 time is set by observing or measuring the time when the output voltage of current supply circuit 121a becomes 0 V or near 0 V, or the time when the output voltage of current supply circuit 121a is lower than the collector voltage of transistor 117.

[0279] At the time when the above voltage relationship reaches a predetermined value (after tb2 has elapsed), the switch circuit 124a is turned on, and the current Ia (=Id) from the current power supply circuit 121a is applied. However, at this time, since the switch circuit 124b is on, the current Ia (=Id) from the current power supply circuit 121a flows to ground (earth line) as current Im via the switch circuit 124b. Therefore, no constant current Id flows through transistor 117. After switch circuit 124a is turned on, and after tb1 time has elapsed, switch circuit 124b is turned off, and the test current Id is supplied to transistor 117. The test current Id is supplied to the transistor 117 in synchronization with the switch circuit 124a, as shown in Figure 31.

[0280] As described above, by operating the switch circuits 124a and 124b, no surge voltage Vs or inrush current Is is applied to transistor 117. Alternatively, the surge voltage Vs or inrush current Is is suppressed, allowing for proper testing of transistor 117.

[0281] When the test current Id to transistor 117 is stopped, switch circuit 124b is turned on before switch circuit 124a is turned off ta2. Through switch circuit Ssb, the constant current Ia output by current power supply circuit 121a flows to ground as current Im and is not supplied to transistor 117.

[0282] The ta2 time is set by observing the time when the output voltage of the current power supply circuit 121a is 0(V) or near 0(V), or when the output voltage of the current power supply circuit 121a is lower than the collector voltage of transistor 117.

[0283] Switch circuit 124a is turned off when the above voltage relationship reaches a predetermined value (after ta2 has elapsed). After switch circuit 124a is turned off, switch circuit 124b is turned off after ta1 time has elapsed.

[0284] As described above, by operating or controlling the switch circuits 124a and 124b in this manner, no surge voltage Vs or inrush current Is is applied to the transistor 117. Alternatively, the surge voltage Vs or inrush current Is is suppressed, allowing for proper testing of the transistor 117.

[0285] When a constant current Id is supplied to transistor 117, the temperature information Tj increases. When the constant current Id to transistor 117 stops, the temperature information Tj decreases. The temperature information Tj fluctuates between T1 and T2. If the characteristics of transistor 117 change due to the test, the temperature information Tj will gradually increase. To apply a constant current Id to transistor 117, the current power supply circuit 121a is activated to apply current Id (=Ia) to transistor 117.

[0286] As shown in Figures 11, 29, 30, 32, 34, and 35, the resistance value of the variable resistor circuit 125 of the gate driver circuit 113 can also be set. By increasing the resistance value, the rising / falling waveform of the gate signal Vgs can be changed as shown by the dotted or dashed line in Figure 32(a).

[0287] By changing or setting the gate signal Vgs, the current Id flowing through transistor 117 can also be changed as shown by the dotted or dashed lines in Figure 32(b). By changing the rising and falling waveforms of the current Id, surge voltage or inrush current can be adjusted or suppressed.

[0288] As shown in Figure 32(c), the temperature information Tj changes from a solid line to a dotted line, and then from a dotted line to a dashed line, as the characteristics of transistor 117 change during the test. The test is stopped when the temperature information Tj reaches the level of Tm. Alternatively, the test is stopped when the rate of change of the temperature information Tj reaches a predetermined value. The test conditions are also changed.

[0289] As shown in Figure 33, when the switch circuit Ssa (switch circuit 124a) is in the off state, the St1 signal is set to H and the temperature information Tj is measured. The St1 signal is set to H level when the gate signal is Vt. During the tn2 period, the St1 signal is set to H level during the tc2 period and the temperature information Tj is measured. During the tn1 period, the temperature information Tj is measured during the tc1 period.

[0290] The temperature information Tj measured during period tc2 is the temperature information Tj at the time when transistor 117 has cooled down. The temperature information Tj measured during period tc1 is the temperature information Tj immediately after the current Id to transistor 117 is stopped. The decision to stop the test, change conditions, or modify the control system will be based on the temperature information Tj measured during period tc2 and the temperature information Tj measured during period tc1.

[0291] If the temperature information Tj measured during period tc1 has a larger rate of change compared to the temperature information Tj measured during period tc2, or if there is a large difference in the absolute value between the temperature information Tj measured during period tc1 and the temperature information Tj measured during period tc2, the test will be controlled and modified in accordance with the measured temperature information Tj.

[0292] Furthermore, if the temperature information Tj measured during the tc2 period differs from the standard value and a predetermined value, the system determines whether there is a problem with the connection status of transistor 117 or the test equipment, and makes a decision such as "do not start the test." During the tc2 or tc1 period, Vi is measured multiple times, and the temperature information Tj for Vi is determined.

[0293] The embodiment shown in Figure 34 is a semiconductor device testing apparatus according to a second embodiment of the present invention. The transistor 117 in Figure 34 is separately provided with diodes Ds (diode Dsa, diode Dsb) for temperature measurement. Note that diode Ds is formed using the same process as transistor 117.

[0294] In the embodiment shown in Figure 34, the temperature information Tj is measured at the timing of the St2 signal shown in Figure 31(d). When the switch circuit Ssa (switch circuit 124a) is in the off state, the St2 signal is set to H and the temperature information Tj is measured. During the tn2 period, the temperature information Tj is measured by setting it to H level during the tc2 period. During the tc1 period, the temperature information Tj may be measured during either the ton period or the tn1 period. The temperature information Tj measured during the tc2 period and the temperature information Tj measured during the tc1 period are averaged to obtain the temperature information Tj.

[0295] Furthermore, Vi is measured multiple times during the tc2 or tc1 period to obtain temperature information Tj for Vi. The operation of the other signals or switch circuits in Figure 31 is the same as or similar to that of the embodiment described in Figure 11, etc. The above examples were embodiments in which temperature information Tj is measured by a diode added to or formed on the transistor 117. In the embodiment shown in Figure 34, a diode Ds that is not connected to (independent of) the transistor 117 is formed.

[0296] Diode Dsa is formed to allow a constant current Ic to flow. Diode Dsb is formed to allow a constant current Ic' to flow. The constant current circuit 118(Pc) generates constant currents Ic and Ic'.

[0297] Diodes Dsa and Dsb are diodes used for temperature measurement. The structures of diodes Dsa and Dsb are similar to or identical to diode Di shown in Figure 11.

[0298] The diodes Di and Dsb operate or have the same configuration, except that diode Di is connected to the terminals (terminals c and e) of transistor 117, while diodes Dsa and Dsb are not connected to the terminals of transistor 117 but to independent terminals, and that the temperature information Tj is measured for diode Di at timing St1 in Figure 31(c), while the temperature information Tj is measured for diodes Dsa and Dsb at timing St2 in Figure 31(d).

[0299] In the embodiment shown in Figure 34, the diode Ds is separated from the path through which the constant current Id flows. Even when the current Id is flowing through the transistor 117, the constant current Ic can still flow through the diode. Therefore, the time for measuring the temperature information Tj can be freely set. As shown in Figure 31(d), the positions of tc1 and tc2 can be set.

[0300] However, in the case of tc2, as shown in Figure 31(d), the gate signal is placed or set during the period of Vt. The temperature information Tj measured during the period of tc2 is used as the value before the transistor 117 operates. The period of tc1 is preferably just before the constant current Id of the transistor 117 is stopped. Alternatively, it may be immediately after the constant current Id is stopped. The time immediately before and immediately after is preferably within 1 millisecond. In Figure 31(d), St2 is a timing signal that controls the current Ic (or current Ic') flowing through the diode Ds (Dsa, Dsb).

[0301] When St2 is at a high level, current flows through the diode Ds (Dsa, Dsb) of transistor 117. The operational amplifier circuit 116 acquires the terminal voltage of diode Ds, and the temperature measurement circuit 115 converts the terminal voltage into temperature information Tj.

[0302] The temperature information Tj is sent to the control circuit board (controller) 111, and the control circuit board (controller) 111 performs, stops, or changes the control of the transistor 117 according to the temperature information Tj.

[0303] When St2 is at a high level, the constant current circuit 118 flows a constant current Ic, which flows through diode Dsa. Additionally, the constant current circuit 118 flows a constant current Ic', which flows through diode Dsb.

[0304] Constant currents Ic and Ic' are currents of the same magnitude. However, if the threshold voltages of diodes Dsa and Dsb are different, or if the characteristics of diodes Dsa and Dsb are different, it is preferable to make the magnitudes of constant currents Ic and Ic' different.

[0305] The operational amplifier circuit 116 acquires the terminal voltage of diode Dsa or Dsb, and the temperature measurement circuit 115 converts the terminal voltage into temperature information Tj. The temperature information Tj is sent to the control circuit board (controller) 111, which then performs a test of transistor 117 based on the temperature information Tj.

[0306] The temperature information Tj obtained by applying a constant current Ic and the temperature information Tj obtained by applying a constant current Ic' are averaged or weighted to obtain a single temperature information Tj value. Using this temperature information Tj, the control circuit board (controller) 111 performs, stops, or changes the control of the transistor 117. Other matters are the same or similar to those described or depicted in this specification and the drawings, and therefore their explanations are omitted.

[0307] It goes without saying that the present invention can be modified in various ways without departing from its essence. It goes without saying that the matters and contents described herein and in the drawings can be combined with each other.

[0308] Figure 35 is an explanatory diagram of a semiconductor device testing apparatus in a third embodiment of the present invention. The difference from Figure 11 is that the diode-connected transistor 117s is positioned in the path of the current Id that flows through the transistor 117m being tested. Other parts are the same and will not be explained.

[0309] Transistor 117s is, for example, a transistor with the same specifications as transistor 117m, which is being tested. The gate terminal g2 and emitter terminal e2 of transistor 117s are connected, and transistor 117s can be considered equivalently as a diode. The gate terminal g2 and emitter terminal e2 of transistor 117s are connected to the O terminal of element terminal 226. The collector terminal c2 of transistor 117s is connected to the P terminal of element terminal 226.

[0310] As shown in Figure 7, the terminals of transistor 117s (gate terminal g2, emitter terminal e2, collector terminal c2) are connected to connector 202b, and connector 202b is connected to sample connection circuit 203 by signal wiring 222b. The connections of the terminals of transistor 117s (gate terminal g2, emitter terminal e2, collector terminal c2) are made within sample connection circuit 203.

[0311] When switch circuit 124b is turned on, a current Im flows, discharging the charge from the current power supply circuit 121a. Alternatively, the current Ia output by the current power supply circuit 121a flows to ground via switch circuit 124b.

[0312] When an inrush current Is flows through the transistor 117m being tested, the transistor 117m is destroyed by the generation of the inrush current Is or surge voltage Vs. To prevent the generation of inrush current Is or surge voltage Vs, the on / off control and on / off sequence of switch circuits 124a and 124b are controlled.

[0313] When testing transistor 117m with a faster period tcycle, it is necessary to switch switch circuits 124a and 124b on and off at high speed. In this case, an inrush current Is or surge voltage Vs may occur depending on the on / off timing of switch circuit 124.

[0314] If the voltage Vm at the collector terminal of transistor 117 is higher than the voltage Vp at the output of the current power supply, then current Im will flow towards ground and either no current or only a small amount will flow through transistor 117m.

[0315] To create the relationship Vm > Vp, in the embodiment shown in Figure 35, the diode-connected transistor 117s is placed in the path of the current Id. When current flows through transistor 117s, the channel voltage of transistor 117s is added to the voltage Vm. Therefore, the voltage Vp becomes lower than the voltage Vm, and no inrush current is applied to transistor 117m. Transistor 117m will not be destroyed by the inrush current Is or surge voltage Vs.

[0316] Figure 36 is an explanatory diagram of a semiconductor device testing apparatus in a fourth embodiment of the present invention. In Figure 36, a plurality of transistors 117 (transistors 117Q1 to 117Qn) to be tested are connected in parallel to the current power supply circuit 121.

[0317] In the fourth embodiment, there is one switch circuit board 201a and n switch circuit boards 201b (switch circuit boards 201b1 to 201bn). There are n transistors 117Q (transistors 117Q1 to 117Qn) that are tested simultaneously or sequentially.

[0318] The collector terminal of transistor Q1 is connected to fork plug 205e1, and the emitter terminal of transistor Q1 is connected to fork plug 205c1.

[0319] The collector terminal of transistor Q2 is connected to fork plug 205e2, and the emitter terminal of transistor Q2 is connected to fork plug 205c2.

[0320] The collector terminal of transistor Q3 is connected to fork plug 205e3, and the emitter terminal of transistor Q3 is connected to fork plug 205c3.

[0321] Similarly, the collector terminal of transistor Qn is connected to fork plug 205en, and the emitter terminal of transistor Qn is connected to fork plug 205cn.

[0322] The current Ic from the constant current circuit 118 is supplied to the diode Ds of the transistor 117Q1 when the switch circuit Ssa1 is turned on. The terminal voltage of diode Ds is applied to the operational amplifier (buffer) 116 and output as the Vi1 voltage from the operational amplifier circuit 116.

[0323] The current Ic from the constant current circuit 118 is supplied to the diode Ds of the transistor 117Q2 when the switch circuit Ssa2 is turned on. The terminal voltage of diode Ds is applied to the operational amplifier (buffer) 116 and output as the Vi2 voltage from the operational amplifier circuit 116.

[0324] Similarly, the current Ic from the constant current circuit 118 is supplied to the diode Ds of the transistor 117Qn when the switch circuit Ssan is turned on. The terminal voltage of diode Ds is applied to the operational amplifier (buffer) 116 and output as the Vin voltage from the operational amplifier circuit 116. Voltage Vin is selected from voltage Vi1 by selector 127, output as Vi, and input to temperature measurement circuit 115.

[0325] The temperature measurement circuit 115 obtains temperature information Tj and outputs it to the control circuit board 111. In the embodiment shown in Figure 36, there is only one constant current circuit 118, but this is not the only option. A constant current circuit 118 may be placed on each transistor 117Q. Alternatively, a temperature measurement circuit 115 may be formed or placed on each transistor 117Q. Voltage data Vi and temperature information Tj are sent to the control circuit board 111 via the wiring on the motherboard 207.

[0326] The element terminal 226 (P terminal) of transistor 117Q1 is connected to the connection structure 218a1. The element terminal 226 (N terminal) of transistor 117Q1 is connected to the connection structure 218b1.

[0327] The element terminal 226 (P terminal) of transistor 117Q2 is connected to the connection structure 218a2. The element terminal 226 (N terminal) of transistor 117Q2 is connected to the connection structure 218b2.

[0328] Similarly, terminal 226 (P terminal) of transistor 117Qn is connected to connection structure 218an. Terminal 226 (N terminal) of transistor 117Qn is connected to connection structure 218bn. Note that n is a positive number greater than or equal to 1. The connecting structure 218 is inserted through an opening 216 provided in the partition wall 217. The insertion of the connecting structure 218 is carried out from room C2 towards room C1.

[0329] The fork plug 205 is inserted into chamber B from chamber C2 through an opening 216 formed in the partition wall 214. By being inserted, the fork plug 205 connects to the conductor plate 204 of the switch circuit board 201. The switch circuit board 201 can be selected by the position of the opening 216 into which the fork plug 205 is inserted.

[0330] By changing the position of the switch circuit board 201 connected to connector 213 on motherboard 207, the switch circuit board 201 to be selected by the fork plug 205 can be selected.

[0331] Two conductor plates 204 are arranged on the switch circuit board 201. The conductor plates 204 are positioned such that the conductor plate 204 closer to the C2 chamber is connected (in contact) with the fork plug 205.

[0332] In the embodiments of the present invention, the fork plug 205 and the conductor plate 204 are electrically connected by contact, but the invention is not limited to this. Any configuration that allows the electrically connected state to be changed between a connected state and a disconnected state by mechanical operation is acceptable. Furthermore, any configuration that can stably maintain the connected state is acceptable.

[0333] For example, instead of the fork plug 205, a rotary connector, rotary joint, high-current connector, etc. may be used. Instead of the conductor plate 204, a rotary connector, rotary joint, high-current connector may be used, or a cylindrical conductor rod, a square conductor rod, a comb-shaped conductor plate, etc. may be used.

[0334] In this specification and in the drawings, the conductor plate 204 is described, but it is not limited to a plate and may be rod-shaped. Any shape is acceptable as long as it can be joined to a structure such as a fork plug 205. For example, it may be a structure such as a socket or connector. Alternatively, the conductor plate 204 may be shaped like a fork plug, and the fork plug 205 and the fork plug may be connected.

[0335] Figure 37 is an explanatory diagram of a semiconductor device test method in an embodiment of the present invention that illustrates the operation shown in Figure 36. It is possible to perform a semiconductor test by simultaneously turning on transistors 117Q (transistors 117Q1 to 117Qn). In this case, a constant current Id must be supplied to all transistors 117Q (transistors 117Q1 to 117Qn). Therefore, the current power supply circuit 121a must be able to output a current of Id × n (where n is a positive number greater than or equal to 1) if there are n transistors 117Q. Consequently, a large-capacity current power supply circuit 121a is required.

[0336] If the transistors 117Q are sequentially turned on and a constant current Id is applied to them during the test, the constant current output by the current power supply circuit 121a can be Id. Figure 37 shows an embodiment of the test method for a semiconductor device test apparatus that performs the test by sequentially turning on the transistors 117Q. The semiconductor device changes depending on the number of times the constant current Id is turned on and off.

[0337] Therefore, by performing the test by sequentially turning on semiconductor elements (transistor 117Q, etc.) as shown in Figure 37, the test can be carried out efficiently, and the maximum output current capacity of the current power supply circuit 121a can be reduced.

[0338] In Figure 37, the explanation assumes that only one transistor 117Q is turned on, but this is not the only option. For example, multiple transistors 117Q may be turned on simultaneously. In this case, the maximum constant current output by the current power supply circuit 121a is equal to the number of transistors 117Q turned on × Id.

[0339] Furthermore, although the current power supply circuit 121a is shown as a single unit in the embodiment of the present invention, it is not limited to this. A separate current power supply circuit 121b may be installed in addition to the current power supply circuit 121a. Alternatively, two or more current power supply circuits 121 may be installed. By installing multiple current power supply circuits 121, the current Id flowing through the transistor 117 can be made into various waveforms. The same applies to the embodiments of the present invention.

[0340] As shown in Figure 37(a), when switch circuits St1 (151s1) to Stn (151sn) are turned on, constant currents Id1 to Idn flow through transistor 117. For example, the application time of constant current Id is ton, and constant currents Id1 and Id2 are applied to transistor 117 sequentially at intervals of time tcycle. When transistor 117 is turned on, the channel voltage of transistor 117Q changes sequentially (Figure 37(c)).

[0341] Therefore, for example, constant currents Id1 and Id2 do not overlap in time. Thus, the output capacitance of the current power supply circuit 121 only needs to be the output capacitance required to test one transistor 117Q.

[0342] The constant currents Id(Id1~Idn) are controlled so that they do not overlap. Preferably, there should be an interval of 1 microsecond or more between each current Id(Id1~Idn). The driving method and control method described in Figure 31 are implemented for each transistor 117Q.

[0343] The constant current Ic supplied to each transistor 117Q is supplied to the diode Ds of each transistor 117Q by sequentially turning on the switch circuit Ssa (Ssa1 to Ssan).

[0344] The voltage Vi (Vi1~Vin) corresponding to the terminal voltage of diode Ds is selected by selector 127 in synchronization with the switch circuit Ssa (Ssa1~Ssan). For example, when current Ic is supplied to transistor 117Q1, selector 127 selects the terminal voltage of diode Ds of transistor 117Q1. When current Ic is supplied to transistor 117Q3, selector 127 selects the terminal voltage of diode Ds of transistor 117Q3. The selected voltage Vi is supplied to the temperature measurement circuit 115. Other configurations and operations are the same as those described in other embodiments, so their explanation will be omitted. In the embodiments of the present invention, transistor 117 has been described using an IGBT as an example, but is not limited thereto.

[0345] For example, it goes without saying that we can also use N-channel JFETs (Figure 38(a)), P-channel JFETs (Figure 38(b)), N-channel MOSFETs (Figure 38(c)), P-channel MOSFETs (Figure 38(d)), N-channel bipolar FETs (Figure 38(e)), and P-channel bipolar FETs (Figure 38(f)).

[0346] Furthermore, the invention is not limited to three-terminal devices, but may also be a two-terminal element such as a diode as shown in Figure 38(g). In the case of a two-terminal element, a gate signal Vgs is not required. It goes without saying that the semiconductor element testing apparatus and semiconductor element testing method of the present invention can be applied by testing with a constant current Id flowing through the current power supply circuit 121.

[0347] Furthermore, it goes without saying that the semiconductor device testing apparatus and semiconductor device testing method of the present invention can be applied not only to transistors and diodes, but also to other semiconductor devices such as thyristors and triacs, varistors and diacs, or modules in which transistors, diodes, resistors, etc., are mixed or integrated.

[0348] Although the present invention has been specifically described above based on embodiments, it goes without saying that the present invention is not limited thereto and can be modified in various ways without departing from its essence. It goes without saying that the matters and contents described in this specification and the drawings can be combined with each other.

[0349] For example, the switch circuits 124a and 124b shown in Figure 30 can be applied to other embodiments. It goes without saying that the configurations or operations shown in Figures 36 and 37 can also be applied to other embodiments such as Figures 34 and 35. [Industrial applicability]

[0350] The present invention provides a semiconductor device testing apparatus and a semiconductor testing method that can be easily modified according to the test content of semiconductor devices such as transistors and the number of semiconductor devices being tested simultaneously, and that can effectively address noise generated during testing. [Explanation of Symbols]

[0351] 111 Control circuit board (controller) 112 Gate signal control circuit 113 Gate driver circuit 115 Temperature measurement circuit 116 Operational Amplifier (Buffer Amplifier) 117 Power Transistors 118 Constant current circuit 121 Current power supply circuit 122 Switch Circuit 124 Switch Circuit 125 Variable Resistor Circuit 126 Variable Resistor Circuit 127 Selector 128 Current detection circuit 129 Voltage detection circuit 130 Constant Current Setting Circuit 131 Control Rack 132 Power supply 133 Control Circuit 134 Heating and Cooling Plate 135 Circulating water pipe 136 Chiller 137 Short Circuit 138 Isolated DC-DC Converter Circuit 201 Switch Circuit Board 202 Connector 203 Sample Connection Circuit 204 Conductor Plate 205 Fork Plug 206 connection pins 207 Motherboard 208 connector 209 Device control circuit board 210 cabinets 211 Connection Wiring 212 Power wiring 213 Connector 214 Bulkhead 215 Bulkhead 216 Opening 218 Connection Structures 219 connecting bolts 220 Contact area 221 Fixing screws 222 Signal Wiring 223 Heat Pipe 224 Fixing screws 225 Contact point 226 element terminals 227 Cooling fan 228 heat dissipation fins 231 Heat pipe fittings 232 Connecting fittings 233 Connecting fitting section 234 recess 236 Spring (Pressure fitting) 237 Position fixing screws 238 screw holes 239 Spring holes 240 positioning screw holes 241 Fork plug insertion plate 251 Convex part 252 Groove 301 Test Circuit Module 302 Voltage Selection Circuit 311 Pressing tool 312 Insulating board 313 Pressing tool mounting plate 315 Insulation part 322 Heating / cooling device 323 Support stand 324 Electrical element insertion holes 325 Slide groove

Claims

1. A power cycle test apparatus for testing a power transistor having a gate terminal and element terminals, A plurality of first switch circuit boards, each having a first switch circuit and a conductive plate or conductive rod connected to the first switch circuit, A gate driver circuit that applies a signal to the gate terminal to turn the power transistor on or off, The system includes a power supply device that supplies a test current or test voltage to the element terminals, The conductor plate or conductor rod has a portion that protrudes from the first switch circuit board, The wiring connected to the element terminals connects to the protruding portion of the conductor plate or conductor rod of any of the multiple first switch circuit boards, thereby forming a path for supplying the test current or test voltage to the element terminals of the power transistor. The power transistor is placed in the first chamber. A power cycle test apparatus characterized in that the first switch circuit board is located in the second chamber.

2. A power cycle test apparatus for testing a power transistor having a gate terminal, element terminals, and a diode element, A plurality of first switch circuit boards, each having a first switch circuit and a conductive plate or conductive rod connected to the first switch circuit, Motherboard and A gate driver circuit that applies a signal to the gate terminal to turn the power transistor on or off, The system includes a power supply device that supplies a test current or test voltage to the element terminals, The conductor plate or conductor rod has a portion that protrudes from the first switch circuit board, The wiring connected to the element terminals connects to the protruding portion of the conductor plate or conductor rod of any of the multiple first switch circuit boards, thereby forming a path for supplying the test current or test voltage to the element terminals of the power transistor. The motherboard and the plurality of first switch circuit boards are connected, The terminal voltage of the diode element is output to the motherboard. The power transistor is placed in the first chamber. A power cycle test apparatus characterized in that the first switch circuit board is located in the second chamber.

3. A power cycle test apparatus for testing a power transistor having a gate terminal, element terminals, and a diode element, A plurality of first switch circuit boards, each having a first switch circuit and a conductive plate or conductive rod connected to the first switch circuit, A gate driver circuit that applies a signal to the gate terminal to turn the power transistor on or off, A constant current circuit that supplies a constant current to the diode element, A voltage output circuit that outputs the terminal voltage of the diode element, The system includes a power supply device that supplies a test current or test voltage to the element terminals, The conductor plate or conductor rod has a portion that protrudes from the first switch circuit board, The wiring connected to the element terminals connects to the protruding portion of the conductor plate or conductor rod of any of the multiple first switch circuit boards, thereby forming a path for supplying the test current or test voltage to the element terminals of the power transistor. When an off signal is applied to the gate terminal of the power transistor, the constant current circuit supplies the constant current to the diode element, and the temperature or temperature change of the power transistor is determined from the terminal voltage output by the voltage output circuit. The power transistor is placed in the first chamber. A power cycle test apparatus characterized in that the first switch circuit board is located in the second chamber.

4. The power cycle test apparatus according to claim 1, 2, or 3, characterized in that a resistor circuit is arranged at the gate terminal and the resistance value of the resistor circuit can be changed.

5. The power supply further comprises a second switch circuit that short-circuits the output terminals of the power supply, When supplying the test current or test voltage to the power transistor, After the second switch circuit short-circuits the output terminals of the power supply, the first switch circuit is turned on to supply the test current or test voltage to the power transistor. When stopping the supply of the test current or test voltage to the power transistor, The power cycle test apparatus according to claim 1, 2, or 3, characterized in that the second switch circuit short-circuits the output terminals of the power supply, and then the first switch circuit is turned off to stop the test current or test voltage from being supplied to the power transistor.

6. The signal to turn off has a first off voltage and a second off voltage. The second off voltage is a voltage lower than the first off voltage. The gate driver circuit periodically supplies the first off voltage, the second off voltage, and the on voltage to the gate terminal. The power cycle test apparatus according to claim 2, characterized in that a constant current is supplied to the diode element and the terminal voltage of the diode element is measured when the second off voltage is applied to the gate terminal of the power transistor.

7. The power cycle test apparatus according to claim 1, 2, or 3, characterized in that a plurality of the first switch circuits are arranged on the first switch circuit board.

8. The power cycle test apparatus according to claim 1, 2, or 3, characterized in that an opening is positioned based on the position of the protruding portion of the conductor plate or conductor rod, and the element terminal and the protruding portion of the conductor plate or conductor rod are connected through the opening.

9. The power cycle test apparatus according to claim 1, 2, or 3, characterized in that the plurality of first switch circuit boards are arranged in parallel.

10. A heating and cooling plate to which a first circulating water pipe for introducing liquid and a second circulating water pipe for discharging the liquid are attached, The system further comprises a leak sensor for detecting the leaked liquid, The power transistor is arranged on the heating and cooling plate. The power cycle test apparatus according to claim 1, 2, or 3, characterized in that the operation of the water leak sensor stops the power cycle test apparatus or issues an alarm.

Images