92 PCB007 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 tradi-
tionally utilize glass to protect the active lay-
ers. 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 visi-
ble light. Many plastics, such as Mylar®, poly-
imide, PET, and ORMOCER® have these char-
acteristics. 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
. PCB007
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 technol-
ogy 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
