74 DESIGN007 MAGAZINE I DECEMBER 2022
suppliers have attempted to address this prob-
lem by using a combination of new formula-
tions of binders in the ink and nanoparticle sil-
ver; so far, results are promising. Table 3 shows
materials and inks used in printed electronics.
Conclusions
Flexible materials are a key characteristic of
printed electronics. Many products tradition-
ally utilize glass to protect the active layers.
To replace glass, the flexible substrates need
to be an effective barrier against oxygen and
water vapor, be sufficiently strong not to rip
or tear and, if a cover, transparent to visible
light. Many plastics, such as Mylar®, polyimide,
PET, and ORMOCER® have these characteris-
tics. Substrates can even be papers and paper
hybrids.
Table 4 shows the suitability of various base
materials to printed electronics applications.
Important to the growing ranks of suitable
substrate materials is "photonic soldering,"
a new technology pioneered by NovaCen-
trix in their PulseForge® product line, which
allows standard lead-free solder pastes to be
soldered without heating the flexible base
materials; this unique ability enables metallic
inks to be sintered/cured without damaging
the substrates
2
. DESIGN007
References
1. "Flexible, Printed and Organic Electronics
2020–2030: Forecasts, Technologies, Markets,"
IDTechEx.com.
2. "Chapter 11: Printed Electronics," by Joe Fjels-
tad, Flexible Circuit Technology, 4th Edition.
3. "Photonic Soldering," by Happy Holden,
PCB007 Magazine, Dec. 20, 2021.
Resources
See "A Review of the Opportunities and Pro-
cesses for Printed Electronics (Part 1)," by Happy
Holden, a white paper originally published for SMTA
International.
Happy Holden has worked
in printed circuit technology
since 1970 with Hewlett-
Packard, NanYa Westwood,
Merix, Foxconn, and Gen-
tex. He is currently a con-
tributing technical editor
with I-Connect007, and the
author of Automation and Advanced Procedures
in PCB Fabrication,
and 24 Essential Skills for Engi-
neers.
To read past columns, click here.
Table 3: Suitability and characteristics of various
PE inks
2
Table 4: Current suitability of base material
substrates for printed electronics applications
1
