We
have seen an increase in cracking.
The
root cause for us is depanelizing using a rotary style blade
cutter.
Caps
and some filters too close to the edge are most subject to
damage
due
to the forces imparted on the board when depanelizing. Often
we
can
eliminate the problem by flipping the board over during depanelize,
but,
that
does not always work and since we do not have the tools to analyze
the
forces during the depanelize process, any changes like flipping the
board
over
is essentially a bit of a gamble.
-Carrie
Cracking Ceramic SMT Capacitors
" Is anyone else
seeing an increase in the number of cracked and shorting ceramic chip
capacitors? In our experience as a contract manufacturer we have,
in the past, seen the occasional instance of ceramic capacitors cracking and
shorting out. The cause of this problem is generally obvious, as it is
isolated to components situated in areas of the PCB that are subject to
flexing.
Recently however we have
seen more frequent instances of this problem; very often in areas of the
board that should not be experiencing any appreciable flex. Our process has
not changed and neither have our sources of these components. Have chip
capacitors themselves become more fragile?"
Rod Lafond
Manager, Quality Assurance and Technical
Training
APEX-Micro Manufacturing
Corporation
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