Bench Top Spatial Magnetic Scanning for Circuit Layer Leakage Detection
Bench-top spatial magnetic scanning isolates subsurface circuit leakage paths non-destructively by mapping current-induced magnetic field profiles across PCB layers.
Layer Depth Estimation
Spatial Measurement
Non-destructive thickness evaluations of insulating and conducting layers in multi-layer boards verify that the internal structure matches the specified build-up sheet. Using layer depth estimation allows the manufacturer to measure the distance from the board surface to internal copper features without cross-sectioning. This measurement is achieved using terahertz imaging or optical coherence tomography.
It ensures that the thickness of dielectric layers is consistent, which is critical for maintaining the target impedance of high-speed traces.
Imaging Procedure
High frequency scanning technologies that map the internal structure of multi-layer laminates locate buried components and measure layer separation. Through layer depth estimation, technicians check the alignment of signal layers and the thickness of prepreg plies after the final lamination press. This process provides feedback to adjust the lamination pressure and temperature profiles, preventing resin squeeze-out and thickness variation.
In high-reliability boards, it verifies that the distance between ground planes and signal lines remains within the allowed tolerances.
Trace Analysis
Impedance modeling based on non-destructive thickness measurements of copper and dielectric layers prevents signal reflections on high speed paths. This analysis utilizes the estimated layer depth to recalculate trace impedance values before the boards are shipped to assembly. It confirms that the physical layer stack-up matches the digital design parameters.