Information processing device, information processing method and program

Abstract

To provide an information processing device capable of easily and accurately determining thermal resistance characteristics.SOLUTION: An information processing device includes: a first calculation unit that, when making a first current flow in a first period, making a second current larger than the first current flow in a second period following the first period, and making the first current flow in a third period following the second period in a semiconductor element, calculates a first relation formula indicating a relation between thermal resistance of the semiconductor element and that in the second period on the basis of a plurality of pieces of data indicating a relation between a difference between a first voltage between predetermined nodes of the semiconductor element in the first period and a second voltage between the predetermined nodes in the third period, and that in the second period; a second calculation unit that calculates a correction value of the thermal resistance on the basis of the first relation formula and a delay time from the starting of the third period until the second voltage is measured; and a third calculation unit that calculates a second relation formula obtained by using the correction value to correct the first relation formula.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an information processing device, an information processing method, and a program. [Background technology]

[0002] The dynamic method is known as a method for determining the thermal resistance of semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) (see, for example, Patent Documents 1 and 2). In the dynamic method, a minute current is passed through the semiconductor element, then a constant current that causes the semiconductor element to heat up is passed through it, and the thermal resistance of the semiconductor element is determined based on the voltage change in the semiconductor element when a minute current is passed through it again. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-211786 [Patent Document 2] JP 2023-65319 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when performing measurements using the dynamic method, a delay time is provided between cutting off the constant current (switching to a minute current) and measuring the voltage in order to suppress the effects of switching the current (chattering, etc.). This delay time can reduce the accuracy of the thermal resistance measurement. In addition, in Patent Document 1, a dummy element having an inductance component approximately equal to that of the element to be measured is used to correct errors, and it is necessary to prepare (and measure) the dummy element in addition to the element to be measured. In Patent Document 2, it is necessary to perform measurements at least twice with different delay times, which takes a long time to measure.

[0005] The present invention has been made in consideration of the above-mentioned problems in the conventional art, and has an object to provide an information processing device that is capable of easily and accurately determining thermal resistance characteristics. [Means for solving the problem]

[0006] The main present invention for solving the above-mentioned problem is an information processing device comprising: a first calculation unit that calculates a first relational equation showing a relationship between a thermal resistance of a semiconductor element and the second period based on a plurality of data showing a relationship between a first voltage between predetermined nodes of the semiconductor element in a first period and a second voltage between the predetermined nodes in the third period and the second period, when a first current is passed through a semiconductor element in a first period, a second current larger than the first current is passed through a second period following the first period, and the first current is passed through a third period following the second period; a second calculation unit that calculates a correction value of the thermal resistance based on the first relational equation and a delay time from the start of the third period to when the second voltage is measured; and a third calculation unit that calculates a second relational equation by correcting the first relational equation using the correction value. Effect of the Invention

[0007] According to the present invention, it is possible to provide an information processing device capable of easily and accurately determining thermal resistance characteristics. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing an example of a configuration for measuring a thermal resistance value Rth of a semiconductor element 1 by a dynamic method. [Diagram 2] FIG. 13 is an explanatory diagram of voltage measurement by a dynamic method performed to calculate a thermal resistance value Rth. [Diagram 3] FIG. 13 is a diagram showing an example of a thermal impedance curve. [Figure 4] 1 is a diagram illustrating an example of a hardware configuration of an information processing device 10. FIG. [Diagram 5] FIG. 2 is a diagram illustrating an example of a functional block realized by the information processing device 10. [Figure 6] 1 is a flow chart showing an example of a method for calculating a thermal impedance curve of a semiconductor element 1 by the information processing device 10 of the present embodiment. [Figure 7] FIG. 1 is a diagram illustrating an example of a Foster model. [Figure 8] FIG. 1 is a diagram illustrating an example of a Cuaer model. [Figure 9] FIG. 1 is a diagram showing a thermal impedance curve Rth[1] and a correction value ΔRth. [Figure 10] FIG. 13 is a diagram showing a thermal impedance curve Rth[2]. [Figure 11] FIG. 13 is a diagram showing a thermal impedance curve Rth[3]. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] At least the following points will become apparent from the description of this specification and the accompanying drawings.

[0010] ===== Implementation form ===== <<About the Dynamic Method>> Figure 1 shows the thermal resistance R of semiconductor element 1 measured by the dynamic method. th FIG. 1 is a schematic diagram showing an example of a configuration for measuring the thermal resistance of a semiconductor module including the semiconductor device 1 and a package (not shown), which is omitted for convenience. The "thermal resistance of the semiconductor device" herein refers to the thermal resistance of a semiconductor module including the semiconductor device 1 and a package (not shown).

[0011] The semiconductor element 1 has a thermal resistance R th The object to be measured is an IGBT in this case. A voltage (e.g., 15 V) that turns on the semiconductor element 1 in the saturation region is applied between the gate and emitter of the semiconductor element 1. A current is supplied to the collector of the semiconductor element 1 from a constant current circuit 3, which will be described later. This causes a current to flow through the path constant current circuit 3 → collector of the semiconductor element 1 → emitter → constant current circuit 3 (ground). The semiconductor element 1 (IGBT) corresponds to a "transistor."

[0012] The test device 2 is a device for measuring the semiconductor device 1 , and includes a constant current circuit 3 and a voltmeter 5 .

[0013] The constant current circuit 3 outputs a constant current of a value according to, for example, an external instruction. For example, the constant current circuit 3 of this embodiment outputs a minute (for example, about 50 to 100 mA) constant current (hereinafter, a minute current I m ) constant current and minute current I m A constant current (hereinafter, the measurement current I C ) constant current. Note that the small current I m corresponds to the "first current" and the measured current I C corresponds to the "second current".

[0014] The voltmeter 5 measures the collector-emitter voltage (V CE The collector of the semiconductor element 1 corresponds to the "power supply side node" and the emitter corresponds to the "ground side node."

[0015] Figure 2 shows the thermal resistance R th 2 is an explanatory diagram of voltage measurement by the dynamic method used to calculate the current flowing through the collector of the semiconductor element 1, and the middle part is a diagram showing the collector-emitter voltage (voltage V CE(sat) ), and the lower part shows the temperature T vj The horizontal axis of each figure is time. vj is not an actual value measured by a sensor or the like, but indicates how the temperature changes when power is supplied to the semiconductor element 1.

[0016] Referring to Figure 2, the thermal resistance value R th The calculation procedure will be explained below.

[0017] At time t0, the constant current circuit 3 in the test device 2 supplies a minute current I m At time t1, the voltage V CEMeasure this with a voltmeter 5 (this measurement is called V m1 (Assuming that.)

[0018] A certain delay time t from time t1 MD At the elapsed time t2, the test device 2 measures the output of the constant current circuit 3 as a current I C Switch to the measurement current I C is the small current I m The current is larger than the rated current of the semiconductor element 1, for example, 10 to 100% of the rated current of the semiconductor element 1. As a result, the semiconductor element 1 is supplied with the measurement current I C is supplied and the temperature T vj increases.

[0019] From time t2, a certain period (pulse width t w At time t3 after the elapse of the test, the test device 2 controls the constant current circuit 3 to measure the current I C Then, the small current I m Then, the measured current I C After the power is turned off (i.e., from time t3), a certain delay time t MD At time t4 (for example, 300 μs) after CE Measure this with a voltmeter 5 (this measurement is called V m2 Furthermore, at time t5, a minute current I m Also blocks.

[0020] First, the small current I m The period during which the measurement current I flows (the period from time t0 to t2) corresponds to the "first period". C The period during which the pulse is passed (time t2 to t3, pulse width t w ) corresponds to the "second period", after which the minute current I m The period during which this is performed (the period from time t3 to t5) corresponds to the "third period."

[0021] At times t2 to t3 in FIG. 2, the voltage V CE(sat) This is because the temperature T vjThis is because the on-state voltage increases as the temperature T vj When the current I increases, the on-state voltage decreases (semiconductor characteristic). For example, m At times t1 and t4, the temperature T vj At time t4, the voltage V m2 is the voltage V at time t1 when the temperature is low m1 It is lower.

[0022] A certain pulse width t w The thermal resistance R of semiconductor element 1 at th can be calculated using the following formula (1). TIFF2025021987000002.tif12170

[0023] Here, ΔT vj is the temperature change (temperature rise) of the semiconductor element 1. K is a constant determined by the element to be measured (here, the semiconductor element 1), and ΔV m is the measured V m1 and V m2 Voltage difference (V m1 -V m2 ).

[0024] In addition, I in Eq. (1) C ×V CE is the pulse width t w This corresponds to the power (W) supplied to the semiconductor element 1 during the period (second period).

[0025] Therefore, from equation (1), the thermal resistance value R th To accurately calculate ΔV m The accuracy of is important.

[0026] The above measurement is performed for pulse width t w By changing the length and repeating this multiple times, a thermal impedance curve (thermal resistance characteristic curve) can be obtained.

[0027] FIG. 3 is a diagram showing an example of a thermal impedance curve.MD The horizontal axis of Fig. 3 is the pulse width t w (s), and the vertical axis is the thermal resistance R th (℃ / W). In the calculation of the thermal impedance curve, w1 , t w2 , t w3 Thermal resistance value R th The value of is approximated using a thermal model (the approximation method using the thermal model will be described later).

[0028] The true thermal impedance curve is also shown in Figure 3. m2 The delay time t MD Due to the existence of delay time t MD Temperature T during vj (The on-state voltage increases due to the semiconductor characteristics described above.) As a result, ΔV m is the actual value (true ΔV m ) is smaller than the thermal resistance R obtained from equation (1). th The value of is the true thermal resistance R th Therefore, each pulse width t w The thermal impedance curve obtained from the measurement is smaller than the true thermal impedance curve.

[0029] In addition, the delay time t MD When switching the current, chattering may occur or V m In order to avoid the influence of instability, the delay time t from time t1 to time t2 is set to a predetermined length (here, 300 μs), and it is difficult to shorten it (for example, set it to zero). MD can be set to be short (in Fig. 2, the delay time t MD are the same, but may be different).

[0030] Delay time t MD As an example of a method for compensating for the effect of delay time t MD By setting multiple delay times t MD When there is no delay time tMD However, this method uses multiple delay times t MD Therefore, it is necessary to perform the same measurement as above for each of the above-mentioned points, which results in a long measurement time.

[0031] In this embodiment, one delay time t MD Using the measurement results for the above, the thermal resistance characteristics are easily and accurately obtained by processing (calculation) by the information processing device 10, which will be described later.

[0032] <<<Configuration of information processing device 10>>> FIG. 4 is a diagram illustrating an example of a hardware configuration of the information processing device 10. As shown in FIG.

[0033] The information processing device 10 is a device (e.g., a computer) that acquires and processes the measurement data of Fig. 2. As shown in Fig. 4, the information processing device 10 includes a CPU (Central Processing Unit) 11, a memory 12, a storage device 13, a communication device 14, a display device 15, and an input device 16, which are interconnected by a bus 18.

[0034] The CPU 11 executes programs stored in the memory 12 and the storage device 13 to realize various functions of the information processing device 10 .

[0035] The memory 12 is, for example, a RAM (Random-Access Memory) and is used as a temporary storage area for programs, data, and the like.

[0036] The storage device 13 is a non-volatile storage unit that stores programs executed (processed) by the CPU 11, various data related to measurements, and the like.

[0037] The communication device 14 exchanges various programs and data with other devices via a network or wiring. For example, the communication device 14 receives (acquires) data related to the measurement of the semiconductor device 1 from the test device 2.

[0038] The display device 15 is, for example, a display, and displays the results of calculations by the CPU 11 and the like.

[0039] The input device 16 is a device that accepts commands and data input by a user, and includes an input interface such as a keyboard, a mouse, and a touch sensor that detects a touch position on a touch panel display.

[0040] FIG. 5 is a diagram illustrating an example of functional blocks realized by the information processing device 10. As shown in FIG.

[0041] When the CPU 11 of the information processing device 10 executes a predetermined program, the information processing device 10 realizes a first calculation unit 21, a second calculation unit 22, a third calculation unit 23, a memory unit 24, a display processing unit 25, a setting unit 26, and a judgment unit 27.

[0042] The first calculation unit 21 calculates the pulse width t w and ΔV m The thermal impedance curve R is based on multiple data showing the relationship th (t w ) is calculated. Below, the thermal impedance curve R th (t w ) is called the thermal impedance curve R th Here, the thermal impedance curve calculated by the first calculation unit 21 is referred to as the thermal impedance curve R th[1] Let us assume that.

[0043] The second calculation unit 22 calculates the thermal impedance curve R th[1] and delay time t MD Based on the correction value ΔR th (t w ) is calculated. Hereafter, the correction value ΔR th (t w ) is the correction value ΔR th The second calculation unit 22 may also abbreviate the thermal impedance curve R th[i] and delay time t MD Based on this, a new correction value ΔRth[i] Here, i is a natural number ranging from 1 to a predetermined number of repetitions (described later).

[0044] The third calculation unit 23 calculates the correction value ΔR th[i] The thermal impedance curve R calculated by the first calculation section is th[1] In this embodiment, a thermal impedance curve close to a true thermal impedance curve can be obtained by calculations in the first calculation unit 21, the second calculation unit 22, and the third calculation unit 23 (described later).

[0045] The storage unit 24 is a section for storing various programs, data, and the like, and is composed of the memory 12 and the storage device 13.

[0046] The display processing unit 25 performs processing for displaying the calculation results of the third calculation unit on the display device 15.

[0047] The setting unit 26 sets the number of repetitions i of the calculations (processing) by the second calculation unit 22 and the third calculation unit 23.

[0048] The determination unit 27 determines whether the number of repetitions i is equal to a predetermined number n.

[0049] <<<How to calculate the thermal impedance curve>>> 6 is a flow chart showing an example of a method for calculating a thermal impedance curve of the semiconductor device 1 by the information processing device 10 of this embodiment. In this embodiment, the test device 2 performs the measurement of the semiconductor device 1 shown in FIG. 2 with a plurality of pulse widths t w The pulse width t w and ΔV m (V m1 , V m2 ) are stored in the storage unit 24.

[0050] First, the information processing device 10 calculates a pulse width t w and ΔV m (V m1 , Vm2 ) is obtained from the storage unit 24 (S01).

[0051] The first calculation unit 21 calculates a pulse width t w and thermal resistance R th The thermal impedance curve R th[1] This thermal impedance curve R th[1] corresponds to the "first relational expression."

[0052] In addition, the thermal impedance curve R th is obtained by approximating it using the Foster model or the Cuer model, which are common thermal impedance models (specifically, by substituting multiple pieces of measurement data into equation (2) described later).

[0053] Fig. 7 is a diagram showing an example of a Foster model. Fig. 7 shows an h-th order (here, 4th order) Foster model. Note that in the thermal model, the parts corresponding to heat are replaced with an electric circuit model (electric resistance and capacitance) so that the thermal resistance characteristics can be calculated by an electric circuit. For example, the heat capacity, which indicates the ease with which an object changes temperature, can be treated as the capacity of a capacitor. In Fig. 7, r1 to r4 are thermal resistances, and c1 to c4 are heat capacities.

[0054] According to the Foster model, the thermal impedance curve can be approximated by the following equation (2). TIFF2025021987000003.tif14170

[0055] Here, τ k is the thermal impedance curve R th (t) is the time constant, and τ k =r k ×c k In addition, h is the order of the model and corresponds to the "predetermined order." In this embodiment, h=4, but is not limited to this and may be an integer other than 4 (for example, 3). In this embodiment, the coefficients of formula (2) (here, rk , τ k ) is required.

[0056] 8 is a diagram showing an example of the Cuer model. Although detailed description is omitted, the Foster model and the Cuer model can be converted into equivalents to each other. Therefore, even if the Cuer model is used as the thermal impedance model, it can be applied as it is by converting it into equivalents to the Foster model in advance.

[0057] Next, the setting unit 26 sets the number of repetitions i to 1 (i=1) (S03).

[0058] The second calculation unit 22 calculates the thermal impedance curve R obtained in step S02. th[1] and delay time t MD Based on and, for each t W Correction value ΔR th (Here, ΔR th[1] ) is calculated using equation (3) (S04). TIFF2025021987000004.tif7170

[0059] In other words, the correction value ΔR th[1] is the thermal impedance curve R th[1] Delay time t MD This is the value obtained by substituting

[0060] Figure 9 shows the thermal impedance curve R th[1] and correction value ΔR th 9 also shows the true thermal impedance and the true error.

[0061] As shown in Figure 9, the thermal impedance curve R th[1] is smaller than the true thermal impedance curve, the correction value ΔR obtained by equation (3) th is always smaller than the true error.

[0062] Next, the third calculation unit 23 calculates the correction value ΔR th[i] (Here, ΔRth[1] ) to obtain the thermal impedance curve R calculated by the first calculation unit 21. th[1] The thermal impedance curve R th[i+1] (Here, R th[2] ) is calculated using equation (4) (S05). Note that the thermal impedance curve R th[2] corresponds to the "second relational expression." TIFF2025021987000005.tif7170

[0063] Figure 10 shows the thermal impedance curve R th[2] FIG. 10 shows the true thermal impedance curve and the thermal impedance curve R th[1] The thermal impedance curve R th[2] is the thermal impedance curve R th[1] In other words, the thermal impedance curve R is closer to the true thermal impedance curve. th[2] is the thermal impedance curve R th[1] and smaller than the true thermal impedance curve.

[0064] Next, the judgment unit 27 judges whether the number of repetitions i is equal to a predetermined number n (S06). If i=n is not satisfied (NO in S06), the setting unit 26 increments the value of i by one (S07) and returns to step S04. Then, steps S04 and S05 are performed again.

[0065] For example, when i=2, in step S04, the second calculation unit 22 calculates the thermal impedance curve R th[2] and delay time t MD Based on this, a new correction value ΔR th[2] Calculate the thermal impedance curve R th[2] is the thermal impedance curve R th[1] is larger than the delay time t MD The correction value ΔR obtained based on th[2] is the correction value ΔR th[1] will be greater than.

[0066] Then, in step S05, the third calculation unit 23 calculates a new correction value ΔR th[2] Using equation (5), the thermal impedance curve R th[1] The thermal impedance curve R th[3] Calculate the thermal impedance curve R th[3] corresponds to the "third relational expression." TIFF2025021987000006.tif7170

[0067] Figure 11 shows the thermal impedance curve R th[3] FIG. 11 shows the true thermal impedance curve and the thermal impedance curve R th[1] ,R th[2] The thermal impedance curve R th[3] is the thermal impedance curve R th[2] It is closer to the true thermal impedance curve than

[0068] The same process is repeated n times (in other words, the second calculation unit 22 calculates the correction value ΔR th is calculated n times). Then, the second calculation unit 22 calculates the correction value ΔR th Each time a new calculation is performed, the third calculation unit 23 calculates the thermal impedance curve R th[1] For example, in the nth time, the thermal impedance curve R shown in the following equation (6) is calculated. th[n+1] Calculate. TIFF2025021987000007.tif7170

[0069] In step S06, when the determination unit 27 determines that i=n (YES in S06), the display processing unit 25 displays the calculation result of the third calculation unit 23 (thermal impedance curve R th[n+1] ) is displayed on the display device 15 (such as a display) (S08), and the process ends.

[0070] By performing such processing, in this embodiment, the thermal impedance is found easily and accurately.

[0071] =====Summary===== The information processing device 10 according to the present embodiment has been described above.

[0072] The information processing device 10 is a device for calculating the thermal resistance characteristics of the semiconductor element 1, and includes a first calculation unit 21, a second calculation unit 22, and a third calculation unit 23. The first calculation unit 21 calculates a minute current I m During the period from time t2 to t3 (pulse width t w ) with a small current I m The measured current I is greater than C During the period from time t3 to t5, a small current I m When a current flows, the collector-emitter voltage V of semiconductor element 1 at time t1 is m1 , and the collector-emitter voltage V of the semiconductor element 1 at time t4 m2 Difference ΔV m and pulse width t w Based on multiple data showing the relationship between the thermal resistance of the semiconductor element 1 and the pulse width t w The thermal impedance curve R th[1] The second calculation unit 22 calculates the thermal impedance curve R th[1] and delay time t MD Based on the correction value ΔR th The third calculation unit 23 calculates the correction value ΔR th Using the thermal impedance curve R th[1] The thermal impedance curve R th[2] Calculate.

[0073] This allows the thermal impedance curve obtained from the measurement to approach the true thermal impedance curve, making it possible to easily and accurately determine the thermal resistance characteristics.

[0074] The second calculation unit 22 calculates the thermal impedance curve R th[2]Once calculated, the thermal impedance curve R th[2] and delay time t MD Based on this, a new correction value ΔR th[2] The third calculation unit 23 calculates a new correction value ΔR th[2] Using the thermal impedance curve R th[1] The thermal impedance curve R th[3] Calculate.

[0075] This makes it possible to further improve the accuracy of the thermal impedance curve.

[0076] The second calculation unit 22 calculates the thermal impedance curve R th[i] Each time, the thermal impedance curve R th[i] and delay time t MD Based on this, a new correction value ΔR th[i] The third calculation unit 23 calculates a new correction value ΔR th[i] Until the calculation is completed n times, the new correction value ΔR th[i] Each time, the thermal impedance curve R th[1] The thermal impedance curve R th[i+1] Calculate.

[0077] This can further improve the accuracy of the thermal impedance curve.

[0078] In addition, the first calculation unit 21 calculates a thermal impedance curve R based on a Foster model or a Cuer model of a predetermined order (fourth order in this embodiment). th[1] is being sought.

[0079] This makes it possible to obtain an approximation curve (thermal impedance curve) of the thermal resistance of the semiconductor element 1.

[0080] In addition, the information processing device 10 calculates ΔV m (V m1 ,V m2 ) and pulse width t wand a display processing unit 25 that causes the display device 15 to display the calculation results of the third calculation unit 23.

[0081] This allows the measurement data to be used to calculate a thermal impedance curve, and the results can be displayed.

[0082] The semiconductor element 1 is a transistor (specifically, an IGBT), and ΔV m (V m1 ,V m2 The node to be measured is between the collector and emitter of the IGBT.

[0083] This makes it possible to obtain the thermal impedance curve (thermal resistance characteristics) of the transistor (IGBT).

[0084] =====Other embodiments===== The above-mentioned embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. Furthermore, the present invention can be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof.

[0085] In the above embodiment, an IGBT has been described as an example of a semiconductor element, but the present invention is not limited to an IGBT and can be applied to various semiconductor elements such as diodes and transistors (for example, bipolar transistors).

[0086] In the above embodiment, when calculating the thermal impedance curve, approximation is performed using the Foster model or the Cuer model as a thermal model, but this is not limited to this and other approximation methods may be used. For example, a thermal impedance curve R can be calculated by an arbitrary function such as the least squares method using multiple measurement points. th[1] An approximation curve of the above may be obtained.

[0087] In the above embodiment, the information processing device 10 performs calculations by acquiring the measurement results (data) obtained by measuring the semiconductor element 1, but this is not limited thereto, and for example, calculations may be performed using data already measured in the past. In this case, a highly accurate thermal impedance curve can be obtained from past data without performing new measurements. [Explanation of symbols]

[0088] 1. Semiconductor element 2. Test Equipment 3 Constant current circuit 5. Voltmeter 10. Information processing device 11 CPU 12. Memory 13 Storage device 14 Communication equipment 15 Display device 16 Input Devices 18 Bus 21 1st calculation section 22 2nd calculation section 23 3rd calculation section 24 Memory section 25 Display processing section

Claims

1. a first calculation unit that calculates a first relational expression that indicates a relationship between a thermal resistance of the semiconductor element and the second period, based on a plurality of data that indicates a relationship between a first voltage between predetermined nodes of the semiconductor element in the first period and a second voltage between the predetermined nodes in the third period, when a first current is passed through a semiconductor element in a first period, a second current larger than the first current is passed through a second period following the first period, and the first current is passed through a third period following the second period; a second calculation unit that calculates a correction value of the thermal resistance based on the first relational expression and a delay time from a start of the third period to a time when the second voltage is measured; a third calculation unit that calculates a second relational expression by correcting the first relational expression using the correction value; An information processing device comprising:

2. 2. The information processing device according to claim 1, The second calculation unit is When the second relational expression is calculated, a new correction value is calculated based on the second relational expression and the delay time; The third calculation unit is calculating a third relational expression by correcting the first relational expression using the new correction value; Information processing device.

3. 2. The information processing device according to claim 1, The second calculation unit is Calculating a new correction value based on the relational expression and the delay time every time the third calculation unit calculates the relational expression; The third calculation unit is calculating a new relational equation obtained by correcting the first relational equation each time the new correction value is calculated until the new correction value is calculated a predetermined number of times; Information processing device.

4. The information processing device according to any one of claims 1 to 3, The first calculation unit determines the first relational expression based on a Foster model or a Cuer model of a predetermined order. Information processing device.

5. The information processing device according to any one of claims 1 to 3, A storage unit that stores the plurality of data; a display processing unit that displays a calculation result of the third calculation unit on a display device; An information processing device comprising:

6. The information processing device according to any one of claims 1 to 3, the semiconductor element is a transistor, the predetermined node is between a node on a power supply side of the transistor and a node on a ground side of the transistor, Information processing device.

7. a first process of calculating a first relational expression showing a relationship between a thermal resistance of the semiconductor element and the second period, based on a plurality of data showing a relationship between a first voltage between predetermined nodes of the semiconductor element in the first period and a second voltage between the predetermined nodes in the third period, the first current being passed through the semiconductor element in a first period, the second current being larger than the first current being passed through the semiconductor element in a second period following the first period, and the first current being passed through a third period following the second period; a second process of calculating a correction value of the thermal resistance based on the first relational expression and a delay time from the start of the third period to the measurement of the second voltage; a third process of calculating a second relational expression obtained by correcting the first relational expression using the correction value; An information processing method implemented by a computer.

8. a first process of calculating a first relational expression showing a relationship between a thermal resistance of the semiconductor element and the second period, based on a plurality of data showing a relationship between a first voltage between predetermined nodes of the semiconductor element in the first period and a second voltage between the predetermined nodes in the third period, the first current being passed through the semiconductor element in a first period, the second current being larger than the first current being passed through the semiconductor element in a second period following the first period, and the first current being passed through a third period following the second period; a second process of calculating a correction value of the thermal resistance based on the first relational expression and a delay time from the start of the third period to the measurement of the second voltage; a third process of calculating a second relational expression obtained by correcting the first relational expression using the correction value; A program that causes a computer to execute the following.

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