A method and system for fast lookup of transient thermal resistance for power semiconductors

Abstract

This invention discloses a method and system for rapid querying of transient thermal resistance in power semiconductors. The method includes: importing raw data containing discrete time series and transient thermal resistance value series; performing logarithmic transformations on the time series and transient thermal resistance value series respectively to obtain logarithmic time series and logarithmic thermal resistance series; receiving one or more time values ​​to be queried by the user; for each time value to be queried, performing a logarithmic transformation, interpolating based on the logarithmic time series and logarithmic thermal resistance series to obtain an intermediate logarithmic thermal resistance value, and performing an antilogarithmic transformation on the intermediate logarithmic thermal resistance value to obtain the final thermal resistance query result; and outputting the correspondence between the time value to be queried and the thermal resistance query result. This invention solves the problems of large errors and low efficiency in the existing technology when interpolating transient thermal resistance data of power semiconductors, and significantly improves the accuracy and efficiency of the query.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, specifically to a method and system for rapidly querying transient thermal resistance of power semiconductors. Background Technology

[0002] Power semiconductor devices (such as IGBTs, MOSFETs, and power diodes) are core components of modern power electronic devices, and their reliability and lifespan are closely related to their operating temperature. Transient thermal resistance is a key parameter describing the heat dissipation characteristics of power semiconductor devices. It reflects the device's ability to transfer heat under transient operating conditions and is fundamental data for junction temperature estimation, thermal simulation, and reliability analysis.

[0003] Currently, power semiconductor device manufacturers typically provide transient thermal resistance data in the form of tables or curves. This data is usually presented as discrete points, covering time ranges from microseconds to seconds or even minutes. However, in practical engineering applications, engineers need to query the thermal resistance value for any given time point, not just the discrete points listed in the table. Because the data is discrete, direct queries often fail to find the target time point, thus requiring interpolation calculations.

[0004] The commonly used solutions in the existing technology have the following problems:

[0005] 1. Large linear interpolation error: Interpolating transient thermal resistance data in a standard linear coordinate system will produce large errors. This is because the transient thermal resistance curve of power semiconductors exhibits strong nonlinear characteristics in a standard linear coordinate system, especially when the time span is large (e.g., from 1μs to 1000s), the data often spans several orders of magnitude.

[0006] 2. Lack of specialized tools: Engineers typically use general-purpose tools (such as Excel) for data processing, but these tools are not designed for processing such specialized data. They are cumbersome to operate, cannot meet the needs of batch queries, and lack targeted accuracy guarantees.

[0007] 3. Inefficiency: For situations where it is necessary to query the thermal resistance values ​​at multiple time points, traditional methods require manual calculation or searching for each value, which is time-consuming and labor-intensive, seriously affecting the efficiency of design analysis.

[0008] 4. Data visualization is not intuitive: Transient thermal resistance data can only show an approximately linear relationship in logarithmic coordinates, which is easier to observe and analyze, while general tools usually require additional steps to achieve logarithmic coordinate display.

[0009] Therefore, there is an urgent need in this field for a dedicated method and system that can quickly and accurately query the transient thermal resistance of power semiconductors to solve the technical problems of large interpolation errors of discrete data points and inconvenience of batch querying. Summary of the Invention

[0010] The purpose of this invention is to provide a method for fast transient thermal resistance lookup for power semiconductors, comprising the following steps:

[0011] Step 1) Import the transient thermal resistance sequence and time series; where there is a corresponding relationship between time and transient thermal resistance;

[0012] Step 2) Filter out invalid data in the transient thermal resistance sequence and time series, and then perform logarithmic transformation on the transient thermal resistance sequence and time series respectively to obtain the logarithmic time series and logarithmic thermal resistance sequence;

[0013] Step 3) Obtain one or more time values ​​from the user through a text input box that interacts with the user;

[0014] Step 4) Determine whether the current time value to be queried does not belong to the time range recorded in the time series. If so, use the boundary thermal resistance value as the thermal resistance query result for the time value to be queried; otherwise, proceed to step 5).

[0015] Step 5) Locate the position of the current time value to be queried in the time series, thereby determining the upper and lower bounds of the interpolation operation;

[0016] Step 6) Perform a logarithmic transformation on the current time value to obtain the logarithmic time to be queried;

[0017] Interpolation calculations are performed on the upper and lower bounds of the interpolation operation, the thermal resistance values ​​corresponding to the upper and lower bounds of the interpolation operation, and the logarithmic query time to obtain the intermediate logarithmic thermal resistance value.

[0018] Step 7) Perform an antilogarithmic transformation on the intermediate logarithmic thermal resistance value to obtain the thermal resistance lookup result;

[0019] Step 8) Repeat steps 4)-7) until you get the thermal resistance query results for all the time values ​​to be queried, and then output the thermal resistance query results.

[0020] Furthermore, logarithmic transformation is a logarithmic operation with base 10.

[0021] Furthermore, the text input box supports manual input, text pasting, and / or file import.

[0022] Furthermore, when the time value to be queried is less than the minimum time value of the time series, the intermediate logarithmic thermal resistance value is as follows:

[0023] (1)

[0024] In the formula, Z is the intermediate logarithmic thermal resistance value; t1 and t2 are the minimum and second minimum time values ​​of the time series; Z1 and Z2 are the thermal resistance values ​​corresponding to t1 and t2.

[0025] Furthermore, when the time value to be queried is greater than the maximum time value of the time series, the intermediate logarithmic thermal resistance value is as follows:

[0026] (2)

[0027] In the formula, Z is the intermediate logarithmic thermal resistance; t n-1 t n Z represents the maximum and second largest time values ​​in the time series. n-1 Z n For t n-1 t n The corresponding thermal resistance value.

[0028] Furthermore, the thermal resistance query results are presented in tabular form, and the order of the query results is consistent with the input order of the time values ​​to be queried.

[0029] Furthermore, the upper bound of the interpolation operation refers to the logarithmic time in the logarithmic time series that is greater than the logarithmic query time and has the smallest difference from the logarithmic query time;

[0030] The lower bound of interpolation is the logarithmic time in the logarithmic time series that is less than the logarithmic query time and has the smallest difference from the logarithmic query time.

[0031] Furthermore, the intermediate logarithmic thermal resistance value is shown below:

[0032] (3)

[0033] In the formula, Z is the intermediate logarithmic thermal resistance; t i t i+1 Z represents the lower and upper bounds for interpolation operations; i Z i+1 These are the thermal resistance values ​​corresponding to the lower and upper bounds of the interpolation operation.

[0034] A rapid transient thermal resistance lookup system for power semiconductors using the method described above includes a data import module, a data preprocessing module, a user input interface module, an interpolation calculation engine, and a result output module.

[0035] The data import module is used to acquire and parse the original data file and extract the time series and transient thermal resistance value series.

[0036] The data preprocessing module performs a logarithmic transformation on the extracted time series and transient thermal resistance value series to obtain a logarithmic time series and a logarithmic thermal resistance series.

[0037] The user input interface module provides a graphical interface for receiving query requests from users, including one or more time values ​​to be queried.

[0038] The interpolation calculation engine is connected to the data preprocessing module and the user input interface module, and is used to perform logarithmic coordinate interpolation algorithm calculation in the logarithmic coordinate plane and perform antilogarithmic transformation on the calculation result;

[0039] The results output module is used to organize and present the query results.

[0040] Furthermore, it also includes a data verification module;

[0041] The data verification module is used to check the validity of the imported raw data and to verify the legality of the time value to be queried entered by the user.

[0042] When checking the validity of the raw data, remove the repetitive pulse thermal resistance sequence data;

[0043] When validating the validity of the time value entered by the user, remove data outside the time period of 1us to 1000ms.

[0044] The technical effects of this invention are undeniable, and this invention has the following significant beneficial effects:

[0045] 1. Significantly Improved Query Accuracy: By performing interpolation calculations in logarithmic coordinates, the nonlinear characteristics of transient thermal resistance data of power semiconductors are fully considered, effectively reducing interpolation errors. Experiments show that compared with traditional linear coordinate interpolation, the method of this invention can reduce the relative error of the query results by more than 60%, especially in regions with large time spans.

[0046] 2. Significantly improved query efficiency: Supports batch query function, which can process more than 20 query requests at a time. The query time is reduced from tens of minutes in the traditional method to within a few seconds, which greatly improves the work efficiency of engineers.

[0047] 3. Simple and easy to use: It provides an intuitive graphical interface and supports multiple input methods (manual input, pasting, and file import), which lowers the barrier to entry and makes it easy for even non-technical personnel to operate.

[0048] 4. Highly Targeted: This invention is a specialized tool developed specifically for the transient thermal resistance data characteristics of the power semiconductor industry. It fully considers the specific needs of the industry and has high practical value.

[0049] 5. High reliability of results: Through scientific algorithm design and reasonable data processing flow, the query results are ensured to meet the engineering accuracy requirements, providing reliable data support for the thermal design and reliability analysis of power semiconductors.

[0050] 6. High scalability: The modular design of the system architecture facilitates subsequent function expansion and algorithm upgrades, and can adapt to thermal resistance data formats from different manufacturers and devices. Attached Figure Description

[0051] Figure 1 Here is a flowchart of the method;

[0052] Figure 2 System block diagram;

[0053] Figure 3 This is the system's user interface;

[0054] Figure 4 This is a practical example. Detailed Implementation

[0055] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0056] Example 1:

[0057] A method for fast transient thermal resistance lookup in power semiconductors includes the following steps:

[0058] Step 1) Import the transient thermal resistance sequence and time series; where there is a corresponding relationship between time and transient thermal resistance;

[0059] Step 2) Filter out invalid data in the transient thermal resistance sequence and time series, and then perform logarithmic transformation on the transient thermal resistance sequence and time series respectively to obtain the logarithmic time series and logarithmic thermal resistance sequence;

[0060] In the transient thermal resistance data, there are five or six thermal resistance curves. Only one of them, a single-pulse thermal resistance curve, is usable. The rest are repetitive pulse thermal resistance curves, which are considered invalid data and are removed.

[0061] Step 3) Obtain one or more time values ​​from the user through a text input box that interacts with the user;

[0062] Step 4) Determine whether the current time value to be queried does not belong to the time range recorded in the time series. If so, use the boundary thermal resistance value as the thermal resistance query result for the time value to be queried; otherwise, proceed to step 5).

[0063] Step 5) Locate the position of the current time value to be queried in the time series, thereby determining the upper and lower bounds of the interpolation operation;

[0064] Step 6) Perform a logarithmic transformation on the current time value to obtain the logarithmic time to be queried;

[0065] Interpolation calculations are performed on the upper and lower bounds of the interpolation operation, the thermal resistance values ​​corresponding to the upper and lower bounds of the interpolation operation, and the logarithmic query time to obtain the intermediate logarithmic thermal resistance value.

[0066] Step 7) Perform an antilogarithmic transformation on the intermediate logarithmic thermal resistance value to obtain the thermal resistance lookup result;

[0067] Step 8) Repeat steps 4)-7) until you get the thermal resistance query results for all the time values ​​to be queried, and then output the thermal resistance query results.

[0068] Example 2:

[0069] A method for quickly querying transient thermal resistance of power semiconductors, with the same technical content as in Embodiment 1, further wherein the logarithmic transformation is a logarithmic operation with base 10.

[0070] Example 3:

[0071] A method for quickly querying transient thermal resistance of power semiconductors, with the same technical content as any one of Embodiments 1-2, further wherein the text input box supports manual input, text pasting and / or file import.

[0072] Example 4:

[0073] A method for rapid transient thermal resistance lookup for power semiconductors, with technical content identical to any one of embodiments 1-3, further comprising the following: when the time value to be queried is less than the minimum time value of the time series, the intermediate logarithmic thermal resistance value is as follows:

[0074] (1)

[0075] In the formula, Z is the intermediate logarithmic thermal resistance value; t1 and t2 are the minimum and second minimum time values ​​of the time series; Z1 and Z2 are the thermal resistance values ​​corresponding to t1 and t2.

[0076] Example 5:

[0077] A method for fast transient thermal resistance lookup in power semiconductors, with the same technical content as any one of embodiments 1-4, further wherein when the time value to be queried is greater than the maximum time value of the time series, the intermediate logarithmic thermal resistance value is as follows:

[0078] (2)

[0079] In the formula, Z is the intermediate logarithmic thermal resistance; t n-1 t n Z represents the maximum and second largest time values ​​in the time series. n-1 Z n For t n-1 t n The corresponding thermal resistance value.

[0080] Example 6:

[0081] A method for rapid query of transient thermal resistance for power semiconductors, with the same technical content as any one of embodiments 1-5, further wherein the thermal resistance query results are presented in tabular form, and the order of the query results is consistent with the input order of the time values ​​to be queried.

[0082] Example 7:

[0083] A method for fast lookup of transient thermal resistance for power semiconductors, with the same technical content as any one of embodiments 1-6, further wherein the upper bound of the interpolation operation refers to the logarithmic time in the logarithmic time series that is greater than the logarithmic time to be looked up and has the smallest difference with the logarithmic time to be looked up;

[0084] The lower bound of interpolation is the logarithmic time in the logarithmic time series that is less than the logarithmic query time and has the smallest difference from the logarithmic query time.

[0085] Example 8:

[0086] A method for rapid lookup of transient thermal resistance for power semiconductors, with the same technical content as any one of embodiments 1-7, further wherein the intermediate logarithmic thermal resistance value is as follows:

[0087] (3)

[0088] In the formula, Z is the intermediate logarithmic thermal resistance; t i t i+1 Z represents the lower and upper bounds for interpolation operations; i Z i+1 These are the thermal resistance values ​​corresponding to the lower and upper bounds of the interpolation operation.

[0089] Example 9:

[0090] A rapid transient thermal resistance lookup system for power semiconductors using the method described in any one of Examples 1-8 includes a data import module, a data preprocessing module, a user input interface module, an interpolation calculation engine, and a result output module.

[0091] The data import module is used to acquire and parse the original data file and extract the time series and transient thermal resistance value series.

[0092] The data preprocessing module performs a logarithmic transformation on the extracted time series and transient thermal resistance value series to obtain a logarithmic time series and a logarithmic thermal resistance series.

[0093] The user input interface module provides a graphical interface for receiving query requests from users, including one or more time values ​​to be queried.

[0094] The interpolation calculation engine is connected to the data preprocessing module and the user input interface module, and is used to perform logarithmic coordinate interpolation algorithm calculation in the logarithmic coordinate plane and perform antilogarithmic transformation on the calculation result;

[0095] The results output module is used to organize and present the query results.

[0096] Example 10:

[0097] A rapid transient thermal resistance lookup system for power semiconductors using the method described in any one of Examples 1-8, with the same technical content as Example 9, further including a data verification module;

[0098] The data verification module is used to check the validity of the imported raw data and to verify the legality of the time value to be queried entered by the user.

[0099] When checking the validity of the raw data, remove the repetitive pulse thermal resistance sequence data;

[0100] When validating the validity of the time value entered by the user, remove data outside the time period of 1us to 1000ms.

[0101] Example 11:

[0102] A method for fast transient thermal resistance lookup in power semiconductors, comprising the following steps:

[0103] 1. Data Import Steps: Import the raw data containing discrete time series and transient thermal resistance value sequences. Preferably, the raw data is provided in Excel spreadsheet format, where the first column is the time series and the second column is the corresponding transient thermal resistance value sequence. The time series typically spans multiple orders of magnitude (e.g., 1µs to 1s), and the transient thermal resistance value sequence also exhibits corresponding nonlinear variation characteristics.

[0104] 2. Data Transformation Steps: The time series and transient thermal resistance value series are logarithmically transformed to obtain the logarithmic time series and logarithmic thermal resistance series, respectively. This step is a key innovation, as it transforms the original nonlinear data into an approximately linear relationship, laying the foundation for subsequent high-precision interpolation calculations. Preferably, the logarithmic transformation is base 10, i.e., using the commonly used logarithm.

[0105] 3. Query Input Steps: Provides a user input interface to receive one or more time values ​​to be queried by the user. In particular, it supports batch input, allowing at least 20 time values ​​to be queried to be entered at once, with input methods including manual input, text pasting, or file import.

[0106] 4. Interpolation Calculation Steps: For each time value to be queried, after logarithmic transformation, interpolation calculation is performed in the logarithmic coordinate plane based on the logarithmic time series and the logarithmic thermal resistance series. After obtaining the intermediate logarithmic thermal resistance value, the value is transformed into an antilogarithmic form (i.e., exponential operation) to obtain the final thermal resistance query result.

[0107] 5. Results Output Steps: Output the query results in a clear and orderly manner. Specifically, the output results need to correspond one-to-one with the input time values, maintaining the same arrangement order for user verification and use. Output formats can include tables, charts, or data files.

[0108] Example 12:

[0109] A method for rapid transient thermal resistance lookup in power semiconductors, with the same technical content as Embodiment 11, further comprising the following specific method:

[0110] Step 1: Data Preprocessing

[0111] Read columns A (time) and B (transient thermal resistance values) from an Excel file, remove non-numerical data, and sort by time in ascending order. Let the preprocessed dataset be... ,in For time, This represents the corresponding transient thermal resistance value.

[0112] Step 2: Precise Match Check

[0113] For query time t, first check if there exists i such that =t (allowed) (Numerical error). If it exists, return directly. As a query result.

[0114] Step 3: Interpolation Interval Positioning

[0115] If an exact match fails, locate the position of query time t in the dataset:

[0116] Case 1 (Interpolation): If ,choose and These serve as the lower and upper bounds for interpolation.

[0117] Case 2 (Extrapolation): If ,choose and Perform extrapolation; if ,choose and Perform extrapolation.

[0118] Step 4: Log-space interpolation calculation

[0119] Linear interpolation is performed in logarithmic space, and the calculation formula is as follows:

[0120] First, take the logarithm of the time and thermal resistance:

[0121]

[0122] Then, linear interpolation is calculated in logarithmic space:

[0123]

[0124] Finally, the result is transformed back into linear space:

[0125]

[0126] Step 5: Return Results

[0127] Return the calculated transient thermal resistance value Z, and indicate the calculation method (exact matching, logarithmic interpolation, or logarithmic extrapolation).

[0128] Example 13:

[0129] A system for fast transient thermal resistance lookup in power semiconductors, comprising the following modules:

[0130] 1. Data Import Module: Used to acquire and parse raw data files, extracting time series and transient thermal resistance value series. This module supports common Excel formats and can handle time data in different units (such as μs, ms, s, etc.).

[0131] 2. Data Preprocessing Module: Connected to the data import module, this module performs logarithmic transformation on the extracted time series and transient thermal resistance series to obtain logarithmic time series and logarithmic thermal resistance series. This module may also include data cleaning functions to remove outliers or invalid data.

[0132] 3. User Input Interface Module: Provides a graphical user interface, including a batch input unit for receiving user-input query requests. This module supports inputting multiple query time values ​​at once and provides data validation functionality to ensure the validity of the input data.

[0133] 4. Interpolation Calculation Engine: As the core processing unit of the system, it connects to the data preprocessing module and the user input interface module. This engine performs interpolation algorithms in the logarithmic coordinate plane and transforms the calculation results into antilogarithms. The engine can use different interpolation algorithms based on user selection or system presets.

[0134] 5. Results Output Module: This module organizes and presents the query results, ensuring a one-to-one correspondence between the results and the entered time values. It offers various output options, including screen display, print output, and data export.

[0135] 6. Data Validation Module: Used to check the validity and consistency of the imported raw data, as well as to verify the legality of the time value entered by the user for querying, to ensure the stability of the system and the reliability of the calculation results.

Claims

1. A method for fast transient thermal resistance lookup in power semiconductors, characterized in that, Includes the following steps: Step 1) Import the transient thermal resistance sequence and time series; where there is a corresponding relationship between time and transient thermal resistance; Step 2) Filter out invalid data in the transient thermal resistance sequence and time series, and then perform logarithmic transformation on the transient thermal resistance sequence and time series respectively to obtain the logarithmic time series and logarithmic thermal resistance sequence; Step 3) Obtain one or more time values ​​from the user through a text input box that interacts with the user; Step 4) Determine whether the current time value to be queried does not belong to the time range recorded in the time series. If so, use the boundary thermal resistance value as the thermal resistance query result for the time value to be queried; otherwise, proceed to step 5). Step 5) Locate the position of the current time value to be queried in the time series, thereby determining the upper and lower bounds of the interpolation operation; Step 6) Perform a logarithmic transformation on the current time value to obtain the logarithmic time to be queried; Interpolation calculations are performed on the upper and lower bounds of the interpolation operation, the thermal resistance values ​​corresponding to the upper and lower bounds of the interpolation operation, and the logarithmic query time to obtain the intermediate logarithmic thermal resistance value. Step 7) Perform an antilogarithmic transformation on the intermediate logarithmic thermal resistance value to obtain the thermal resistance lookup result; Step 8) Repeat steps 4)-7) until you get the thermal resistance query results for all the time values ​​to be queried, and then output the thermal resistance query results.

2. The method for fast transient thermal resistance lookup for power semiconductors according to claim 1, characterized in that, Logarithmic transformation is a logarithmic operation with base 10.

3. The method for rapid transient thermal resistance lookup for power semiconductors according to claim 1, characterized in that, The text input box supports manual input, text pasting, and / or file import.

4. The method for fast transient thermal resistance lookup for power semiconductors according to claim 1, characterized in that, When the time value to be queried is less than the minimum time value of the time series, the intermediate logarithmic thermal resistance value is as follows: （1） In the formula, Z is the intermediate logarithmic thermal resistance value; t1 and t2 are the minimum and second minimum time values ​​of the time series; Z1 and Z2 are the thermal resistance values ​​corresponding to t1 and t2.

5. The method for fast transient thermal resistance lookup for power semiconductors according to claim 1, characterized in that, When the time value to be queried is greater than the maximum time value of the time series, the intermediate logarithmic thermal resistance value is as follows: （2） In the formula, Z is the intermediate logarithmic thermal resistance; t n-1 t n Z represents the maximum and second largest time values ​​in the time series. n-1 Z n For t n-1 t n The corresponding thermal resistance value.

6. The method for fast transient thermal resistance lookup for power semiconductors according to claim 1, characterized in that, The thermal resistance query results are presented in tabular form, and the order of the query results is consistent with the input order of the time values ​​to be queried.

7. The method for fast transient thermal resistance lookup for power semiconductors according to claim 1, characterized in that, The upper bound of interpolation operation refers to the logarithmic time in the logarithmic time series that is greater than the logarithmic query time and has the smallest difference from the logarithmic query time. The lower bound of interpolation is the logarithmic time in the logarithmic time series that is less than the logarithmic query time and has the smallest difference from the logarithmic query time.

8. The method for fast transient thermal resistance lookup for power semiconductors according to claim 1, characterized in that, The intermediate logarithmic thermal resistance values ​​are shown below: （3） In the formula, Z is the intermediate logarithmic thermal resistance; t i t i+1 Z represents the lower and upper bounds for interpolation operations; i Z i+1 These are the thermal resistance values ​​corresponding to the lower and upper bounds of the interpolation operation.

9. A system for rapid transient thermal resistance lookup of power semiconductors using the method of any one of claims 1-9, characterized in that, It includes a data import module, a data preprocessing module, a user input interface module, an interpolation calculation engine, and a result output module; The data import module is used to acquire and parse the original data file and extract the time series and transient thermal resistance value series. The data preprocessing module performs a logarithmic transformation on the extracted time series and transient thermal resistance value series to obtain a logarithmic time series and a logarithmic thermal resistance series. The user input interface module provides a graphical interface for receiving query requests from users, including one or more time values ​​to be queried. The interpolation calculation engine is connected to the data preprocessing module and the user input interface module, and is used to perform logarithmic coordinate interpolation algorithm calculation in the logarithmic coordinate plane and perform antilogarithmic transformation on the calculation result; The results output module is used to organize and present the query results.

10. The transient thermal resistance fast lookup system according to claim 8, characterized in that, It also includes a data verification module; The data verification module is used to check the validity of the imported raw data and to verify the legality of the time value to be queried entered by the user. When checking the validity of the raw data, remove the repetitive pulse thermal resistance sequence data; When validating the validity of the time value entered by the user, remove data outside the time period of 1us to 1000ms.

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