Abstract
IC pad damage from a wafer probe can be detrimental to wire-bond yield and product reliability. In this paper, bond pads are harshly probed on traditional pads and a variety of experimental circuit-under-pad (CUP) structures in technologies having aluminum (Al) metallization and silicon dioxide (SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) dielectric films. Probe marks and cracking behavior are analyzed, seeking process margins for high-reliability products. Results follow the well-known dependencies on chuck overdrive, probe touch counts, and cantilever probe tip length. Additional detail is revealed regarding the probe mark area, the interaction of cracks with top vias, sublayer film deformation that leads to cracks, and decreased cracking with increased pad Al thickness. The presence of a full sheet of metal in a pad sublayer dominates the top SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> cracking performance in the pad. A dramatic improvement in robustness to cracking is seen as the bond pad sublayer metal films reduce in pattern density. Deformation or ripple in metal sublayer features can be prevented or minimized, thus preventing bending and cracking of the top SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and increasing the capability for high-reliability CUP pads. Based on these experimental results, CUP pad objectives can be achieved even with harsh probing on thin pad Al.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Transactions on Components, Packaging and Manufacturing Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
