Damage Detection Technique Using Ultrasonic Guided Waves And Outlier Detection: Application To Interface Delamination Diagnosis Of Integrated Circuit Package

This paper presents the development of a robust data-driven damage diagnosis technique to accurately detect sealant delamination in an integrated circuit (IC) package. A sealant is used to bond the integrated heat spreader (IHS) to the substrate of IC packages for effective thermal dissipation. Delamination of the sealant causes significant reduction in heat management capability of the package, which leads to degradation of processor performance and component reliability. In this work, non-destructive evaluation (NDE) using ultrasonic guided wave (UGW) is performed to interrogate the integrity of the IC package. The advantage of using UGW is its large area inspection capability and small defect detection sensitivity. Ultrasonic tests using a pitch-catch active sensing method with removable piezoelectric (PZT) tranducers are performed with a wide range of excitation frequencies to classify various delamination scenarios in the IC package. Data preprocessing and Hilbert transform-based feature extraction method are also performed on the collected UGWs to extract dominant UGW features. Pattern analysis using a density-based spatial clustering of applications with noise (DBSCAN) algorithm is conducted on the UGW feature space to classify the damage indicators. These damage indicators (outliers) are then used to identify the IC packages with sealant delamination. The proposed technique is validated by comparing it to dye-and-pry tests, delamination metrics, and detection method using a multivariate Gaussian model. The results demonstrate that the proposed diagnosis technique has the potential to be a part of the industrial quality assurance process for IC packages for its capability to detect manufacturing defects with high accuracy.(c) 2021 Elsevier Ltd. All rights reserved.