Article
FFF 3D Printing in Electronic Applications: Dielectric and
Thermal Properties of Selected Polymers
David Kalaš * , Karel Šíma , Petr Kadlec , Radek Polanský , Radek Soukup , Jan
ˇ
Reboun
and Aleš Hamáˇcek
Citation: Kalaš, D.; Šíma, K.; Kadlec,
P.; Polanský, R.; Soukup, R.;
ˇ
Reboun,
J.; Hamáˇcek, A. FFF 3D Printing in
Electronic Applications: Dielectric
and Thermal Properties of Selected
Polymers. Polymers 2021, 13, 3702.
https://doi.org/10.3390/
polym13213702
Academic Editors: Ludwig Cardon
and Clemens Holzer
Received: 7 October 2021
Accepted: 25 October 2021
Published: 27 October 2021
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Attribution (CC BY) license (https://
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4.0/).
Faculty of Electrical Engineering, University of West Bohemia, Univerzitní 8, 301 00 Pilsen, Czech Republic;
karels@fel.zcu.cz (K.Š.); kadlecp6@fel.zcu.cz (P.K.); rpolansk@fel.zcu.cz (R.P.); rsoukup@fel.zcu.cz (R.S.);
jreboun@fel.zcu.cz (J.
ˇ
R.); hamacek@fel.zcu.cz (A.H.)
* Correspondence: kalasd@fel.zcu.cz; Tel.: +420-377-634-536
Abstract:
The present study is a focused and comprehensive analysis of the dielectric and ther-
mal properties of twenty-four 3D printed polymers suitable for fused filament fabrication (FFF) in
electronic applications. The selected polymers include various thermoplastic elastomers, such as
thermoplastics based on polycarbonate (PC), polyethylene terephthalate glycol (PETG), and acryloni-
trile butadiene styrene (ABS-T). Their overall thermal behavior, including oxidation stability, glass
transition, and melting temperature, was explored using simultaneous thermal analysis (STA) and
differential scanning calorimetry (DSC). Considering their intended usage in electronic applications,
the dielectric strength (E
p
) and surface/volume resistivity (
ρ
s
/
ρ
v
) were comprehensively tested
according to IEC 60243-1 and IEC 62631-3, respectively. The values of the dielectric constant (
ε
’)
and loss factor (
ε
”) were also determined by broadband dielectric spectroscopy (BDS). While, on the
one hand, exceptional dielectric properties were observed for some thermoplastic elastomers, the
materials based on PCs, on the other hand, stood out from the others due to their high oxidation
stability and above average dielectric properties. The low-cost materials based on PETG or ABS-T did
not achieve thermal properties similar to those of the other tested polymers; nevertheless, considering
the very reasonable price of these polymers, the obtained dielectric properties are promising for
undemanding electronic applications.
Keywords: 3D printing; filament materials; dielectric parameters; thermal parameters
1. Introduction
The 3D printing of polymer materials is currently a widely used additive technology,
especially in rapid prototyping. Nevertheless, considering the price of injection molding
forms, 3D printing is naturally becoming increasingly common in high-mix, low-volume
(HMLV) commercial production. A significant advantage of 3D printing is the low price
and high availability of 3D printers and the low production costs. Therefore, 3D printing,
together with a wide range of commercially available polymer filaments; the possibility
of multicolor printing; and the availability of biodegradable and chemically or mechani-
cally resistant materials, is becoming widespread in various production fields, including
electronics. On the other hand, the 3D printing of an extensive series of products is time
consuming; the final treatment to produce a smooth surface without visible layers is a nec-
essary step; there is limited temperature resistance; and the filaments can absorb moisture
and lose adhesion during the printing process [1].
Fused filament fabrication (FFF) can be used in several processes, e.g., for (i) the
encapsulation of surface mount devices (SMDs) or printed circuit boards (PCBs) on tex-
tile substrates by the thermocompression method [
2
]; (ii) structural electronics [
3
,
4
]; (iii)
devices used in explosive atmospheres [
5
]; (iv) high-frequency electronic applications, in
which wireless communication and data transmission are used [
6
,
7
]; or (v) power electron-
ics [
8
]. Despite the fact that in such applications properly designed dielectric and thermal
Polymers 2021, 13, 3702. https://doi.org/10.3390/polym13213702 https://www.mdpi.com/journal/polymers
