Page 30 - Chip Scale Review_May June_2023-digital

Summary
In this article, we have compared
i n s p e ct ion i m age s w it h va r iou s
illumination techniques for the inspection
of ABF via residue, dry-film resist after
development, and Cu seed after etching.
For the inspection of via residue following
®
LEADERS IN the laser ablation of ABF, Clearfind
technology was found to be the most
MICRO DISPENSING effective tool for identifying residue. For
the inspection of dry-film resist after
TECHNOLOGY development, the simultaneous use of CF
and DF illumination was the best choice
because the former technology could easily
SMALL REPEATABLE VOLUMES find under-developed dry-film resist or
ARE A CHALLENGE, BUT NOT residue inside the via, and DF could find
IMPOSSIBLE IF YOU HAVE BEEN metallic defects in the Cu area. Regarding
CREATING THEM AS LONG AS WE HAVE. inspection after the Cu seed etching
process, CF illumination was the most
efficient inspection technology because it
clearly shows open or short defects without
TO DO IT WELL, showing false defects that may come from
rough and grainy surfaces when inspected
WE PROVIDE THREE THINGS: by BF or DF.

Acknowledgments
The authors wish to express their
Dispensing Expertise in a variety of microelectronic sincere thanks to Dong-Heon Kang
packaging applications. at Samsung Electro-Mechanics, and
Wesley Chou and Kazuko Jochi at Onto
Feasibility Testing & Process Verification based Innovation, for their valuable discussions.
on years of product engineering, material flow testing
and software control. References
1. H. Hichri, et al., “Fine line routing and
Product Development for patented valves, micro via patterning in ABF enabled
dispensing cartridges, needles, and accessories. by excimer laser ablation,” IMAPS,
Oct. 2017, pp. 113-119.
2. D. C. Harris, M. D. Bertolucci,
Symmetry and Spectroscopy, Dover
Publications, New York, 1978, pp.
307-418.
Our Micro Dispensing product line is proven and trusted by 3. G. Singh, “Reveal previously invisible
manufacturers in semiconductor, electronics assembly, medical defects and contaminants in advanced
device and electro-mechanical assembly the world over. packaging applications,” Solid State
www.dltechnology.com. Technology, Nov./Dec. 2017, pp. 11-15.
4. W. Young Han, “Reveal invisible
defects on large 600mm panels,” Chip
216 River Street, Haverhill, MA 01832 • P: 978.374.6451 • F: 978.372.4889 • info@dltechnology.com
Scale Review, Jan./Feb. 2021, pp. 39-
43.

Biography
Dr. Cheolkyu Kim is a Senior Director of Applications at Onto Innovation, Wilmington, MA USA.
Prior to joining Onto, Kim was a postdoctoral research associate in the Physics Department of Brown U.
He received a PhD in Physics from the U. of Rhode Island and a Master’s degree in Physics Education
from Seoul National U., Seoul, Korea. His research has been published in various scientific journals.
Email Cheolkyu.Kim@ontoinnovation.com

28 Chip Scale Review May • June • 2023 [ChipScaleReview.com]
28