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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