Semiconductor Chip Temperature Estimation via Integrated Thermistor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor chip temperature estimation methods require a separate thermistor in the cooling body, increasing the number of parts, cost, and size of the power converter, and are ineffective in accurately estimating temperatures when heat is generated by semiconductor chips far from the thermistor.
Innovation Solution
A semiconductor chip temperature estimation device that incorporates a thermistor within the semiconductor module, using a first estimation unit to calculate chip loss, a memory to store correlations between temperature rise and chip loss, and a third estimation unit to calculate the cooling element temperature by subtracting the thermistor's temperature rise from its detected value, allowing accurate estimation without a separate thermistor in the cooling body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate thermistor is installed in the cooling body to detect cooling medium temperature, then temperature detection accuracy is improved, but the number of parts increases, leading to increased cost and size
Solution Approach 1:
The patent merges the temperature detection function into the semiconductor module by incorporating a thermistor within the module housing. This allows the same thermistor to detect both the semiconductor chip temperature (via thermal conduction through the module structure) and the cooling medium temperature (via the housing), eliminating the need for separate temperature sensors in the cooling body and reducing the overall number of parts.
Solution Approach 2:
The thermistor incorporated in the semiconductor module serves multiple functions: it detects the temperature of the semiconductor chip through thermal conduction, detects the temperature of the cooling medium through the module housing, and enables temperature-based control decisions. This multi-functionality eliminates the need for separate dedicated cooling medium temperature sensors.
2Device complexity
If a thermistor is incorporated in the semiconductor module to reduce parts, then device complexity is reduced, but temperature estimation accuracy deteriorates when heat is generated by semiconductor chips far from the thermistor
Solution Approach 1:
The patent introduces the cooling medium temperature as an intermediary reference value. Instead of directly measuring all chip temperatures, the system uses the cooling medium temperature (detected by the thermistor in the housing) as a baseline reference. The semiconductor chip temperature is then estimated by adding the temperature rise (calculated from chip loss and thermal resistance) to this reference cooling medium temperature, enabling accurate estimation even for chips far from the thermistor.
Solution Approach 2:
The patent replaces direct thermal conduction measurement (mechanical/physical contact required) with a calculation-based estimation method. Instead of requiring the thermistor to be in direct thermal contact with all semiconductor chips, the system calculates the temperature rise based on chip loss and thermal resistance parameters, then adds this to the cooling medium temperature reference, eliminating the need for direct thermal contact with all heat-generating components.
3Device complexity
If cooling medium temperature is used as reference for temperature estimation, then device complexity is reduced, but reliability deteriorates when the reference temperature does not reflect actual chip temperature conditions
Solution Approach 1:
The patent implements a feedback mechanism where the estimated semiconductor chip temperature (calculated by adding temperature rise to cooling medium temperature) is continuously monitored and compared against a predetermined threshold. When the estimated temperature exceeds the threshold, the control device automatically reduces the drive current to the semiconductor chip, creating a closed-loop feedback system that ensures reliable overheat protection despite using cooling medium temperature as the reference.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the number of parts and cost, while accurately estimating cooling element and semiconductor chip temperatures, enabling reliable overheat protection by limiting current based on estimated temperatures.
Implementation Method 1
a value of temperature detected by a thermistor incorporated in a semiconductor module
Implementation Method 2
temperature of a cooling element, which cools the semiconductor module
Implementation Method 3
temperature of a cooling element, which cools the semiconductor module
Data Source
AI summary
A semiconductor chip temperature estimation device that estimates the temperature of a semiconductor chip incorporated together with a thermistor in a semiconductor module includes a first estimation unit which calculates a first estimation value of a chip loss of the chip, a memory which stores in advance a correlation between a temperature rise of the temperature sensor and the chip loss of the chip, a second estimation unit which calculates a second estimation value of the temperature rise of the temperature sensor, and a third estimation unit which calculates a third estimation value of the temperature of the cooling element. The temperature of the semiconductor chip is estimated by using the third estimation value as a base temperature.