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Summary
Our RISPAC technology addresses
a w ide ra nge of dev ices for low-
density applications. Silicon body
ty pe FOWLP, which is one of our
FOWLP technologies, is suitable for
small and thin products with ultra-
small and ultra-thin dies. The single-
die mounting tech nology we call,
silicon body type, is used for ultra-
thin packages where the thickness can
be up to 160μm maximum.
Our dual-die mounting technology
enables two dies to be mounted in a
stack and electrically connected in
a small, compact package, without
h a v i ng t o u s e ex p e n s i v e T S V
Figure 7: Optimized layout and resistance distribution (of a daisy chain TEG). technology. We confirmed that 90μm
terminal pitch devices are achievable
by optimizing the design rules for a three-dimensional
pa ck age st r uct u re. More ove r, u si ng ou r FOW LP
technology, called silicon body type RDL-1st, we were
able to achieve the required performance and reliability.
Mass production of the RDL-1st FOWLP technology was
launched at ROHM’s Kyoto factory in 2017 and is now
at a mature stage. Shipments have exceeded one billion
pieces in volume and have achieved zero-defect quality.
In conclusion, we have demonstrated that our RDL-1st
FOWLP technology is suitable for mass production.

References
1. S. H. Zhang, F. Che, T. Lin, W. Zhao, Modeling, Analysis,
Design, and Tests for Electronics Packaging beyond
Moore, Woodhead Pub., 2019, pp. 2-3.
2. H. Araki, et al., “Fabrication of redistribution structure
using highly reliable photosensitive polyimide for fan-out
panel-level packages,” Proc. of IWLPC, Oct. 2018.
3. P. Metzger, et al., “Toward a flip-chip bonder dedicated
to direct bonding for production environment,” Proc. of
IWLPC, Oct. 2017.

Biographies
Isamu Nishimura is FOWLP Development Specialist at ROHM Co., Ltd., Kyoto, Japan. He joined ROHM in 1985
and is engaged in process development from 3μm LSI to 90nm LSI, memory lines and WLCSPs. He was appointed
Project Manager of RISPAC technology in 2014 and developed functional devices and FOWLPs based on LSI
processing technology. He also established its mass production lines. Email Isamu.Nishimura@lsi.rohm.co.jp

Mamoru Yamagami is a Staff Engineer at ROHM Co., Ltd., Kyoto, Japan.

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