design the stackup carefully and use a
tool that can handle the entire flex and
One of the biggest challenges with
rigid-flex designs is qualifying multiple
manufacturers. After the design is completed, all aspects of the design must be
communicated to the board fabricator
so that it will be properly manufactured.
However, the best practice is to choose
one or more manufacturers early in
the design and collaborate with them
to ensure your design matches their
fabrication requirements as the design
progresses. Collaborating with fabricators is simplified by using standards. In
this case, IPC-2223 is the vehicle for
communicating with your fabricators.
Once the design is complete, the
data package must be assembled to
hand-off to be manufactured. While
Gerber is still used for standard PCBs
in some companies, when it comes to
the complexities of rigid-flex, it is high-
ly recommended by both PCB software
tool vendors as well as fabricators that
a more intelligent data exchange format
be used. The two most popular intel-
ligent formats are ODG++ (version 7
or later) and IPC-2581, both of which
clearly specify layer requirements.
The vast majority of PCBs in the world
today are basically rigid plates to connect circuitry. The vast majority of the
human body is flexible and in motion.
Mixing the two creates challenges that
can only be solved with rigid-flex PCB
Moving to flexible circuitry opens
up a set of challenges beyond those
for rigid boards. Care must be taken
with stackup design, trace designs on
the flexible substrates, and 3D bending.
Then, more care must be taken in se-
lecting, collaborating with, and supply-
ing design data to the board fabricator.
The best way to ensure that your
rigid-flex design works correctly and
is delivered on-time and on-budget is
to employ leading-edge PCB design
software and take advantage of the
Mark Forbes is Director of Marketing
Content for Altium. Mark has a BSEE
from Bradley University in Peoria, Illinois.
He holds patents in optical communications as well as antenna design. Mark has
written more than 150 technical articles
and five books. MDT