Title :
Plasma Surface Modification and Impact on MSL Performance for Flip Chip Packaging
Author :
Teo, Mary ; Lee, Ka Yau ; Chew, Alex ; Lim, Simon ; Lee, Charles ; Nonomura, Masaru
Author_Institution :
Infineon Technol. Asia Pacific Pte. Ltd., Singapore
Abstract :
The effectiveness of "under-chip" plasma cleaning and its impact on moisture sensitivity level (MSL) performance for flip chip packaging was investigated in this study. A customized test vehicle was designed for surface analysis on the flip chip silicon nitride (SiN) passivation and substrate solder mask surfaces. Optimization of the plasma conditions was achieved using contact angle measurement, adhesion testing, and verified with X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) analysis. The impact of plasma cleaning on MSL performance was assessed using a molded flip chip in package (FCIP) test vehicle. It was found that significant adhesion enhancement of SiN passivation to underfill can be achieved by a synergistic combination of the following plasma surface modifications: removal of organic contaminants, formation of certain functional groups (C=0, O-C-O and 0-C=0), and an increase in effective surface area. In summary, this study has demonstrated the benefits of an optimized "under-chip" plasma cleaning process for MSL performance improvement of a molded FCIP. Findings from this extensive plasma characterization also enable a better understanding on how plasma surface modification can contribute towards packaging of more robust products.
Keywords :
X-ray photoelectron spectra; adhesion; atomic force microscopy; chip scale packaging; contact angle; flip-chip devices; integrated circuit reliability; integrated circuit testing; moisture; passivation; plasma materials processing; scanning electron microscopy; silicon compounds; solders; surface cleaning; AFM; SEM analysis; SiN; X-ray photoelectron spectroscopy; XPS; adhesion enhancement; adhesion testing; atomic force microscopy; contact angle measurement; customized test vehicle design; effective surface area; flip chip packaging; moisture sensitivity level impact; molded flip chip in package test vehicle; organic contaminants removal; plasma conditions optimization; plasma surface modification; scanning electron microscopy; silicon nitride passivation; substrate solder mask surfaces; surface analysis; under-chip plasma cleaning process; Atomic force microscopy; Cleaning; Flip chip; Packaging; Plasma applications; Plasma measurements; Scanning electron microscopy; Silicon compounds; Testing; Vehicles;
Conference_Titel :
Electronics Packaging Technology Conference, 2007. EPTC 2007. 9th
Conference_Location :
Singapore
Print_ISBN :
978-1-4244-1323-2
Electronic_ISBN :
978-1-4244-1323-2
DOI :
10.1109/EPTC.2007.4469787