Solderjoint_No2_Magazin - Flipbook - Page 66
Passion for soldering
Weller: When did you first come into contact
with soldering, and what fascinated you
about it?
I first came into contact with soldering back
in elementary school. I started by buying
electronic kits and soldering them together
– often selling the finished products to my
classmates. Some of them got so inspired
that they bought their own soldering irons,
and two of them eventually became electrical engineers themselves. Even today, I’m still
fascinated by the moment something I built
comes to life. That feeling never gets old.
Weller: What does soldering mean to you
as an engineer – craft, science, or both?
Definitely both – no question about it!
Soldering is where science, engineering, and
craft all come together. There are often
many different ways to solve a micro-soldering challenge, and choosing the right one
requires not just technical knowledge, but
also a steady hand, experience, and the kind
of intuition that only comes with practice. It’s
a beautiful blend of precision and artistry.
Weller: What is the most demanding solder
joint you’ve ever worked on – and why?
The most demanding soldering task I’ve ever
worked on was building a detector readout
test rig for the Exoplanet Characterization
Observatory (EChO) mission. It involved the
Teledyne SIDECAR ASIC, the same cryogenic
detector readout electronics used on the
Hubble Space Telescope. Not only is it one
of the few ASICs that operates at cryogenic
temperatures, but the development kit
itself was incredibly expensive and came
with extremely small, delicate connectors.
Designing a custom PCB and handsoldering all the components was a real
challenge – technically, because of the
precision required, and mentally, because I
was fully aware of how much each part cost.
One wrong move, and it could mean many
thousands of euros lost.
One major concern with lead-free solder in
aerospace applications is the formation of
tin whiskers–tiny, hair-like metallic filaments
that can grow spontaneously from tin-rich
surfaces. These whiskers can cause short
circuits, potentially leading to mission failure.
Traditionally, adding lead (Pb) to solder
alloys significantly suppressed whisker
growth, which is why many space agencies
and aerospace manufacturers still prefer
leaded solder for mission-critical systems,
despite the global push for lead-free
electronics. The reliability requirements in
space simply outweigh the environmental
considerations in these cases.
The role of soldering in the space industry
Weller: What makes soldering for aerospace and satellite missions fundamentally different?
Soldering for aerospace and satellite missions is fundamentally different because
there’s no room for failure. In space, repairs
aren’t possible, every joint must be perfect
from the start. You’re working with extreme
reliability requirements, harsh environmental
conditions like vacuum and radiation, and
often cryogenic temperatures and wide
thermal cycles. On top of that, all materials
and processes must meet strict standards
for outgassing, thermal cycling, and mechanical stress. It’s not just about making it
work–it’s not just about surviving the
extreme vibration of the rocket during
launch, but making it work flawlessly for decades at the extreme conditions of space.
Weller: Can you share some of the standards or quality checks that apply specifically to space-related soldering?
Space-related soldering is governed by
extremely strict standards to ensure longterm reliability under extreme conditions.
Both NASA and ESA have strict standards for
hand soldering, covering everything from
materials and workmanship to inspection
and training. It emphasizes high-reliability
connections and includes visual, X-ray and
other inspection and documentation criteria.
Weller: What role does durability play in the
soldering process for components that are
launched into orbit?
Durability is critical. Solder joints must withstand intense vibration during launch,
extreme temperature cycles in orbit, and
