Quantifying Interface Thickness Variances in Pack Thermal Layers
Quantifying interface thickness variances across pack thermal layers prevents localized hot spots, cell degradation splits, and unallocated warranty exposure.
Ultrasonic Acoustic Scanning
Meaning
Nondestructive evaluation methods utilize high frequency sound pulses to identify internal material discontinuities in bonded assemblies. Using ultrasonic acoustic scanning allows technicians to see inside a battery pack without disassembling the components. The return of sound waves reveals the location of hidden defects.
Echo Behavior
Acoustic energy travels through solid materials but bounces back when it hits an air gap or a change in density. By monitoring the return echo, ultrasonic acoustic scanning determines if an adhesive layer has pulled away from the cell. This technique is highly sensitive to delamination.
Interface Resolution
Higher frequencies provide better detail but have less penetration depth in dense materials. In the context of battery production, ultrasonic acoustic scanning identifies voids as small as a few microns in size. The data is often presented as a color-mapped image showing the quality of the bond.
Volume Analysis
Testing covers the entire depth of the sample to ensure that internal layers are correctly aligned. While other methods only check the surface, ultrasonic acoustic scanning provides a view of the internal structural health. This is a standard tool for validating new manufacturing processes.
It is particularly effective for identifying the growth of delamination over time, as the high-resolution images can be compared across different stages of a stress test to see how defects propagate under load.