Abstract
The development of advanced packaging is essential in the semiconductor manufacturing industry. However, non-destructive testing (NDT) of advanced packaging becomes increasingly challenging due to the depth and complexity of the layers involved. In such a scenario, Magnetic field imaging (MFI) enables the imaging of magnetic fields generated by currents. For MFI to be effective in NDT, the magnetic fields must be converted into current density. This conversion has typically relied solely on a Fast Fourier Transform (FFT) for magnetic field inversion; however, the existing approach does not consider eddy current effects or image misalignment in the test setup. In this paper, we present a spatial-physics informed model (SPIM) designed for a 3D spiral sample scanned using Superconducting QUantum Interference Device (SQUID) microscopy. The SPIM encompasses three key components: i) magnetic image enhancement by aligning all the "sharp" wire field signals to mitigate the eddy current effect using both in-phase (I-channel) and quadrature-phase (Q-channel) images; (ii) magnetic image alignment that addresses skew effects caused by any misalignment of the scanning SQUID microscope relative to the wire segments; and (iii) an inversion method for converting magnetic fields to magnetic currents by integrating the Biot-Savart Law with FFT. The results show that the SPIM improves I-channel sharpness by 0.3% and reduces Q-channel sharpness by 25%. Also, we were able to remove rotational and skew misalignments of 0.30 in a real image. Overall, SPIM highlights the potential of combining spatial analysis with physics-driven models in practical applications.
Abstract (translated)
先进封装技术在半导体制造业中至关重要，然而由于其层层深入且复杂度高，对先进封装进行无损检测（NDT）变得愈发困难。在这种情况下，磁场成像(MFI)能够实现由电流产生的磁场的成像。为了使MFI在NDT中有效，必须将这些磁场转换为电流密度。这一过程通常仅依赖于快速傅里叶变换(FFT)来进行磁场反演；然而，现有的方法并未考虑到涡流效应或测试装置中的图像错位问题。 本文介绍了一种专为使用超导量子干涉仪(SQUID)显微镜扫描三维螺旋样品设计的空间物理信息模型（SPIM）。该模型包括三个关键组成部分： 1. 通过同步对相位(I通道)和正交相位(Q通道)的“尖锐”线场信号进行校准，来增强磁场图像，以减轻涡流效应的影响。 2. 磁场图像校准，用于解决由于SQUID显微镜相对于导电线段位置错位所引起的偏斜问题。 3. 将毕奥-萨法尔定律与FFT结合使用，将磁场转换为磁电流的反演方法。 实验结果表明，SPIM使I通道的“尖锐度”提高了0.3%，同时减少了Q通道的“尖锐度”25%。此外，在真实图像中成功消除了0.30度的旋转和偏斜错位。总的来说，SPIM展示了结合空间分析与物理驱动模型在实际应用中的巨大潜力。
URL
https://arxiv.org/abs/2507.11853
