Acoustic Defect Detection in Bonded Power Electronic Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power electronic devices in applications like electric vehicles face mechanical defects due to thermomechanical stresses caused by coefficient of thermal expansion mismatches between components, leading to issues like cracking and delamination, which existing technologies fail to detect effectively.
Innovation Solution
A system utilizing piezoelectric devices attached to the electronic device and bonding layer to transmit and receive acoustic signals, allowing for the detection of mechanical defects in the bonding layer and interfaces through analysis of signal propagation, with a controller determining defect locations using machine learning and adjustable measurement configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If piezoelectric devices are attached to transmit and receive acoustic signals for defect detection, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The piezoelectric devices serve multiple functions: they act as both transmitters and receivers of acoustic signals, and can be positioned on different components (electronic device or bonding layer) to detect various types of defects. This multi-functionality improves measurement precision while avoiding the need for separate dedicated transmitter and receiver systems, thereby limiting the increase in device complexity.
Solution Approach 2:
The system uses the existing structural components (electronic device and bonding layer) as part of the detection system itself. The piezoelectric devices attached to these components utilize the components' own material properties and structures to transmit and receive acoustic signals, eliminating the need for additional external testing equipment and reducing overall system complexity.
2Reliability
If acoustic signals are used to detect sub-surface defects in bonding layer and interfaces, then reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The detection method extracts and isolates the acoustic signal transmission and reception functions from the overall manufacturing process. By using acoustic waves that propagate through the bonding layer and interfaces, the system can detect sub-surface defects without requiring precise attachment of piezoelectric devices to specific locations, as the acoustic signals naturally traverse the entire structure including bonding interfaces.
Solution Approach 2:
Acoustic waves serve as an intermediary medium that bridges the gap between the piezoelectric devices and the sub-surface defects in the bonding layer and interfaces. The acoustic signals can penetrate through these layers and reflect off or transmit through defects, providing detection capability without requiring direct contact or precise positioning at the defect locations, thereby reducing manufacturing precision requirements.
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 accurate detection of sub-surface defects in power electronic modules, preventing mechanical and thermal failures by identifying defects in the bonding layer and interfaces, thereby improving the reliability of power electronic assemblies.
Implementation Method 1
A first subset of the one or more piezoelectric devices is configured to transmit one or more acoustic signals
Implementation Method 2
A second subset of the one or more piezoelectric devices is configured to receive the one or more acoustic signals
Implementation Method 3
the one or more acoustic signals after the one or more acoustic signals propagate in the electronic apparatus
Data Source
AI summary
Aspects of the disclosure provide a method including determining a measurement configuration for one or more piezoelectric devices in an electronic apparatus. The electronic apparatus includes an electronic device mounted on a substrate block using a bonding layer. The one or more piezoelectric devices including a first subset and a second subset are attached to one of the electronic device and the bonding layer. The method includes performing, based on the measurement configuration, a defect measurement on the electronic apparatus by causing the first subset to transmit and the second subset to receive one or more acoustic signals. The method includes determining whether at least one mechanical defect is located in at least one of (i) the bonding layer, (ii) the electronic device, (iii) the substrate block, (iv) interfaces of the electronic device, the bonding layer, and the substrate block based on the received one or more acoustic signals.