This study presents an innovative approach to constructing a representative system matrix in x-ray imaging forward models. The approach leverages the combination of machine learning algorithms and fundamental physical principles through the use of physics-informed machine learning (PIML). The main goal is to seamlessly integrate machine learning algorithms with core physical principles to provide a nuanced perspective on the development of an interpretable and adaptive system matrix. In contrast to traditional data-intensive methods, this research intentionally prioritizes the incorporation of physics-based constraints into the machine learning framework. The methodology involves carefully extracting relevant features from x-ray imaging data to capture essential object characteristics, which are then integrated into a machine learning model. By including physics-based constraints, the model aligns with the underlying principles that govern x-ray interactions. Through rigorous mathematical validation and preliminary experimentation, the approach demonstrates its feasibility, particularly in situations where acquiring extensive datasets is challenging. From a technical standpoint, the strength of this methodology lies in the inherent adaptability and interpretability of the system matrix, which are crucial for accurate image reconstruction and measurement prediction. The implications of this research span diverse domains and highlight the potential transformative effects on x-ray imaging applications in electronics, medical imaging, and material inspection. In the realm of electronics, the adaptable system matrix improves non-destructive testing by aiding in defect detection and ensuring the reliability of electronic components. In medical imaging, enhanced interpretability leads to improved diagnostic accuracy while reducing radiation exposure. In material inspection, this approach facilitates the identification of structural anomalies and material composition, thereby advancing quality control practices. While recognizing the preliminary nature of the framework, this study lays the groundwork for future research at the intersection of machine learning and physics in x-ray imaging, representing a progressive step towards unlocking transformative possibilities for enhanced accuracy and adaptability across various domains.
This study scrutinizes the limitations and challenges of applying non-destructive techniques such as Scanning Acoustic Microscopy (SAM) and 3D x-ray imaging for testing 3D and 2.5D integrated circuit (IC) packaging configurations. As the semiconductor industry moves towards advanced packaging technologies like 2.5D and 3D heterogeneous integration, which integrates various dies or chiplet components vertically and horizontally to enhance device performance and reduce costs, ensuring the reliability of these complex structures becomes paramount. This paper presents a comprehensive review of the current state-of-the-art non-destructive methods used for physical inspection, characterization, and failure analysis, with a focus on SAM and 3D x-ray imaging. It discusses the pressing challenges faced by these methods due to ongoing miniaturization and the need for high precision in inspecting densely packed components. An empirical investigation is conducted through a case study of a multi-die advanced packaging scenario to evaluate the practical utility of SAM and 3D x-ray techniques. This examination includes comparisons of resolution, analysis window size, aiming to understand the benefits of integrating these imaging modalities. The study also explores the future needs and opportunities for advancement in imaging hardware and algorithm development for automated signal interpretation and AI-assisted defect detection. This investigation highlights the critical role of non-destructive methods in advancing semiconductor packaging technologies while addressing their current limitations and the path forward for enhancing IC package integrity and reliability.
Printed circuit boards (PCBs) are indispensable components that enable the functionality of modern electronics applications. Ranging from various densities and uniqueness by design, the attack surfaces of these devices are vast and complex. In secure/critical domains like medical, automotive, and defense, the authenticity of these devices is critical to mitigate losses in trust and security. Not only does their complexity and responsibility in a hardware system pose an issue, but the globalization of their supply chain further emphasizes the necessity of methods to validate their designs. In this paper, the authors propose a novel framework for furthering PCB trust by addressing pitfalls in verifying the connectivity design of PCBs. Incorporating data from both imaging modalities into a cohesive model framework aims to address the shortfalls of single-modality autonomous netlist approaches.
KEYWORDS: Thermoreflectance, Manufacturing, Digital watermarking, Reliability, Integrated circuits, Information security, Temperature metrology, Semiconductors, Reflection, Inspection
In the quest to secure the authenticity and ownership of advanced integrated circuit (IC) packages, a novel approach has been introduced in this paper that capitalizes on the inherent physical discrepancies within these components. This method, distinct from traditional strategies like physical unclonable functions (PUFs) and cryptographic techniques, harnesses the unique defect patterns naturally occurring during the manufacturing process. By employing thermo-reflectance imaging (TRI), a non-destructive evaluation technique, in this proposed method we inspect, characterize and localize defects within IC package structures such as Through-silicon Vias (TSV) and micro-bumps. TRI’s ability to detect minute temperature variations caused by defects enables the creation of a detailed map that outlines the specific locations and types of manufacturing irregularities. This novel technique leverages the uniqueness of each IC’s defect pattern to generate an inherent identifier or ’fault-mark.’ These identifiers are derived from the specific arrangement and combination of defects, making them virtually impossible to replicate or forge due to the randomness and complexity of the manufacturing process variations. The creation of these fault-marks offers a robust and tamper-resistant means of authentication, providing a reliable method for establishing proof of ownership for advanced IC packages. The implementation of this approach not only can enhance supply chain security but also acts as a deterrent against the counterfeiting of IC packages. By verifying the authenticity of ICs against a reference database of fingerprints captured during the post-silicon validation stage, stakeholders can ensure the integrity of their components. This method’s potential of using inherent fingerprinting for reliable authentication and traceability of advanced IC packages is also been discussed, thereby offering a promising solution to the challenges of counterfeiting and unauthorized reproduction in the electronics industry.
KEYWORDS: Inspection, Adversarial training, Education and training, Data modeling, Visual process modeling, Performance modeling, Computer vision technology, Defense and security, Systems modeling, Process modeling
This study aims to investigate the potential of enhancing the resilience of computer vision systems in the context of intelligent Printed Circuit Board (PCB) inspection through the integration of techniques that filter out adversarial examples. PCBs, which are crucial components of electronic devices, require reliable inspection methods. However, current computer vision models are vulnerable to adversarial attacks that can compromise their accuracy. Our research introduces an evolving approach that combines advanced deep learning architectures with adversarial training methods. The initial steps involve training a robust PCB inspection model using a diverse dataset and generating adversarial examples through carefully designed perturbations. Subsequently, the model is exposed to these adversarial examples during a dedicated training phase, enabling it to adapt to variations introduced by potential adversaries. To counter the impact of adversarial examples on classification decisions during real-time inspections, a filtration mechanism is implemented to identify and discard them. Preliminary experimentation and ongoing evaluations demonstrate promising progress in enhancing the resilience of PCB inspection models against adversarial attacks. Although the filtration mechanism is still in its early stages, it shows potential in identifying and neutralizing potential threats, contributing to efforts aimed at strengthening the reliability and trustworthiness of inspection outcomes. Moreover, the adaptability of the proposed methodology to various PCB designs, including different components, orientations, and lighting conditions, indicates the potential for transformative advancements in computer vision systems in critical domains. This research underscores the need for continued investigation into the evolving landscape of adversarial example filtration, presenting a potential avenue for fortifying intelligent inspection systems against adversarial threats in PCB inspection and beyond.
In the domain of printed circuit board (PCB) X-ray inspection, the effectiveness of deep learning models greatly depends on the availability and quality of annotated data. The utilization of data augmentation techniques, particularly through the utilization of synthetic data, has emerged as a promising strategy to improve model performance and alleviate the burden of manual annotation. However, a significant question remains unanswered: What is the optimal amount of synthetic data required to effectively augment the dataset and enhance model performance? This study introduces the Synthetic Data Tuner, a comprehensive framework developed to address this crucial question and optimize the performance of deep learning models for PCB X-ray inspection tasks. By employing a combination of cutting-edge deep learning architectures and advanced data augmentation techniques, such as generative adversarial networks (GANs) and variational autoencoders (VAEs), the Synthetic Data Tuner systematically assesses the impact of different levels of synthetic data integration on model accuracy, robustness, and generalization. Through extensive experimentation and rigorous evaluation procedures, our results illustrate the intricate relationship between the quantity of synthetic data and model performance. We elucidate the phenomenon of diminishing returns, where model performance reaches a saturation point beyond a specific threshold of synthetic data augmentation. Moreover, we determine the optimal balance between synthetic and real data, achieving a harmonious equilibrium that maximizes performance improvements while mitigating the risk of overfitting. Additionally, our findings emphasize the significance of data diversity and quality in the generation of synthetic data, highlighting the importance of domain-specific knowledge and context-aware augmentation techniques. By providing insights into the complex interplay between synthetic data augmentation and deep learning model performance, the Synthetic Data Tuner not only advances the current state-of-the-art in PCB X-ray inspection but also offers valuable insights and methodologies applicable to various computer vision and industrial inspection domains.
Segmentation of printed circuit board (PCB) components from X-ray images holds paramount significance as it constitutes a crucial step in design extraction and reverse engineering processes. Conventional pretrained deep learning segmentation models demand considerable resources and produce less-than-optimal outcomes and often results in overfitting due to the scarcity of the labeled PCB X-ray data. The Segment Anything Model (SAM), known for its versatility in semantic segmentation tasks, showcases its capability to effectively segment a wide array of objects found in natural images. Nonetheless, it encounters challenges when it comes to the complex design of PCB X-ray images, causing difficulty in accurately segmenting the components present in the circuit boards design. Adapting this foundation model to the unique challenges posed by PCB X-ray images, such as intricate component structures and variations in X-ray artifacts, requires careful modification and optimization. In this study, we propose a customized approach for segmenting components from X-ray images of PCBs that use a modified SAM model with parameter-efficient fine-tuning and few-shot generalization strategies. We introduce modifications to enhance the model’s ability to capture intricate spatial relationships and effectively segment individual components. Our methodology focuses on the efficient adaptation of the foundation model to the unique characteristics of PCB X-ray images, including complex component structures and varying noise conditions. Leveraging few-shot learning techniques, we address the challenge of limited annotated data in the PCB X-ray domain, towards the aim of enabling the model to generalize effectively with minimal fine-tuning. Our work has the potential to pave the way for a novel solution to the challenge of implementing deep learning in a limited dataset by leveraging the capabilities of a foundation model.
The global outsourcing of semiconductor fabrication has led to hardware security concerns such as counterfeit Integrated Circuits (ICs) and Hardware Trojans (HTs), compromising the trustworthiness of semiconductor devices in critical applications. To address the issue of counterfeit ICs and HTs, various physical inspection methods have been developed. These methods, which include x-ray imaging, Scanning Acoustic Microscopy (SAM), and Scanning Electron Microscopy (SEM), are employed to detect irregularities within the packaging of ICs, aiding in the identification of counterfeit samples and the detection of HTs. Previous studies have shown that encapsulant material differences in counterfeit ICs can be detected by observing the refractive index variance between genuine and counterfeit products. This is achieved by measuring layer thickness and time delay in THz-TDS. THz-TDS employs a pulsed Terahertz signal to discern the effective refractive index differences between authentic and counterfeit IC packaging. However, anomaly detection often requires high resolution, which is time-consuming and necessitates standard samples for comparison, which are challenging to obtain. In this research, we focus on generating a THz-TDS ’fingerprint’ for each IC sample for hardware assurance, rather than detecting packaging anomalies. This paper explores using both supervised and unsupervised machine learning models to demonstrate the effectiveness of THz-TDS ’fingerprinting’ in IC sample identification. We also investigate the tolerance of THz-TDS data collection locations to identify various types of IC packaging. This involves collecting THz-TDS data from different IC packaging samples at multiple locations to assess the impact on accuracy in sample identification.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.