Traceback Analysis of Unknown Nanoparticles Formation Mechanism on OSP Surface Finished PCB for Flip-Chip Package

Ha-Yeong Kim; Jiwon Kim; Yeon-Ryong Chu; Suk Jekal; Minki Sa; Chan-Gyo Kim; Gyu-Sik Park; Jisu Lim; Zambaga Otgonbayar; Chang-Min Yoon

doi:10.1109/ACCESS.2024.3427728

IEEE Access (Jan 2024)

Traceback Analysis of Unknown Nanoparticles Formation Mechanism on OSP Surface Finished PCB for Flip-Chip Package

Ha-Yeong Kim,
Jiwon Kim,
Yeon-Ryong Chu,
Suk Jekal,
Minki Sa,
Chan-Gyo Kim,
Gyu-Sik Park,
Jisu Lim,
Zambaga Otgonbayar,
Chang-Min Yoon

Affiliations

Ha-Yeong Kim: Department of Chemical and Biological Engineering, Hanbat National University, Daejeon, South Korea
Jiwon Kim: Department of Chemical and Biological Engineering, Hanbat National University, Daejeon, South Korea
Yeon-Ryong Chu: Department of Chemical and Biological Engineering, Hanbat National University, Daejeon, South Korea
Suk Jekal: Department of Chemical and Biological Engineering, Hanbat National University, Daejeon, South Korea
Minki Sa: Department of Chemical and Biological Engineering, Hanbat National University, Daejeon, South Korea
Chan-Gyo Kim: Department of Chemical and Biological Engineering, Hanbat National University, Daejeon, South Korea
Gyu-Sik Park: Department of Intelligent Nano Semiconductor, Hanbat National University, Daejeon, South Korea
Jisu Lim: Department of Intelligent Nano Semiconductor, Hanbat National University, Daejeon, South Korea
Zambaga Otgonbayar: Department of Chemical and Biological Engineering, Hanbat National University, Daejeon, South Korea
Chang-Min Yoon: ORCiD; Department of Chemical and Biological Engineering, Hanbat National University, Daejeon, South Korea

DOI: https://doi.org/10.1109/ACCESS.2024.3427728
Journal volume & issue: Vol. 12
pp. 97132 – 97142

Abstract

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In this paper, we present the concept of traceback analysis to identify the origins of non-wet defects caused by hydrophobic unknown nanoparticles in the semiconductor packaging process. Traceback analysis involves five-steps, i.e., practical observation of failure mode, detailed physical and chemical analysis, process investigation, hypothesis establishment, and failure reproduction with comparison. Initially, the morphology and composition of the unknown nanoparticles are analyzed using an optical microscope (OM), field-emission scanning electron microscopy (FE-SEM), contact angle (CA), energy-dispersive spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FT-IR). As a result, spherical unknown nanoparticles with a size of ca. 500 nm consists of organic imidazole-derived materials, similar to the composition of organic solderability preservative (OSP). To identify the origin, printed circuit board (PCB) manufacturing processes are reviewed step-by-step. Traceback analysis identifies that the 1-methoxy-2-propyl acetate (PGMEA) cleaning solvent can form spherical emulsions when mixed with deionized (DI) water during the cleaning process. This can occur when PGMEA and DI water mix in the cleaning bath or recycling pipes, or when leftover PGMEA and DI water mix during next cleaning processes. These PGMEA/DI water form emulsions owing to the polarity differences between hydrophobic PGMEA and hydrophilic DI water and remain on the PCB surface. Thus, organic nanoparticles grow in the PGMEA emulsion on the Cu pad during OSP application for surface finishing purposes. This comprehensive approach ensures a thorough understanding of defect origins. The traceback analysis described in this study, involving five-steps, is applicable not only in semiconductor packaging but also in defect investigation across various industries.

Published in IEEE Access

ISSN: 2169-3536 (Online)
Publisher: IEEE
Country of publisher: United States
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering
Website: https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=6287639

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