Semiconductor Module Deterioration Detection Circuit
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Solution Overview
Problem
Existing semiconductor modules, such as IPMs, face challenges in detecting deterioration of the joining parts between the IGBT chip and the insulating circuit board, which can lead to heat-related issues and potential malfunctions, as current detection methods only address deterioration between the IGBT chip and the wire.
Innovation Solution
A semiconductor module with a deterioration detecting circuit that applies a DC voltage between two main electrode terminals, using one as a reference potential, and compares the gate voltage and inter-main-electrode voltage with reference values to output an alarm signal and potentially block the drive signal to prevent further operation when deterioration is detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current detection methods are used, then deterioration between IGBT chip and wire can be detected, but deterioration between IGBT chip and insulating circuit board cannot be detected
Solution Approach 1:
The detection method is segmented into two distinct detection paths: one for wire joining part deterioration (using wire resistance) and another for insulating circuit board joining part deterioration (using solder joint resistance). This segmentation allows each detection function to be optimized independently, enabling precise detection of both types of deterioration without interference.
Solution Approach 2:
The patent introduces intermediary measurement points and resistance detection circuits that indirectly measure the condition of joining parts. By measuring resistance changes in the solder joints and wire connections through electrical pathways, the system can detect physical deterioration without direct physical access to the joining parts, solving the detection limitation.
2Measurement precision
If DC voltage is applied between main electrode terminals, then joining part deterioration can be detected through voltage comparison, but additional circuit complexity is introduced
Solution Approach 1:
The DC voltage application circuit and voltage comparison circuit serve multiple functions: they detect both wire joining part deterioration and insulating circuit board joining part deterioration using the same basic infrastructure. The resistance detection unit and voltage comparison unit are designed to handle multiple detection scenarios, reducing the need for separate dedicated circuits for each detection type.
Solution Approach 2:
The semiconductor module's own main electrode terminals and gate electrode terminal are utilized as the measurement points for detection, eliminating the need for external test equipment. The module's internal voltage distribution during normal operation is harnessed to provide the DC voltage for detection, and the existing terminal structure serves dual purposes for both operation and diagnostics.
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
Enables early detection of joining part deterioration, preventing malfunctions and accidents by outputting an alarm when voltage thresholds are exceeded, and blocking the drive signal to prevent operation before the joining part fails.
Implementation Method 1
the IGBT chip 2 has a collector 2c, which is connected to a collector terminal 11 through the wiring pattern part 56 and is affected by a resistance component 4 between the solder layer 58 and the wiring pattern part 56 placed under the IGBT chip
Data Source
AI summary
A semiconductor module including a semiconductor element which is bonded to a wiring pattern part and connects or disconnects two main electrode terminals to or from each other according to a drive signal applied to a gate electrode terminal, includes a deterioration detecting circuit configured to use one main electrode terminal of the two main electrode terminals of the semiconductor element with an applied DC voltage, as a reference potential, and detect deterioration of a joining part of the semiconductor element on the basis of a gate voltage which is the voltage between the one main electrode terminal and the gate electrode terminal and an inter-main-electrode voltage which is the voltage between the one main electrode terminal and the other main electrode terminal, and outputs an alarm signal.