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| Standard
Ics - Quad Flat Packages |
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QFP
has a wide range of lead counts starting from 44
leads and going to as high as 256 leads. The more
popular lead counts in QFP are 64, 80, 100, 144,
160, and 208. There are many challenges in manufacturing
QFP lead frames because of its delicate and fine
features.
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| The
inner leads are long and flimsy, thus the leads
very susceptible to movement or shifting. Taping
is used to hold the leads in place, but the inert
requirement of the tape material adds significant
cost to the lead frames. Stamping tools used in
mass-producing these high count lead frames (160
and above) are enormous, costly, and difficult to
maintain and therefore chemical etching is often
the better alternative method used than stamping.
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