paulkoning at comcast.net
Thu Jul 21 18:56:23 CDT 2016
> On Jul 21, 2016, at 7:07 PM, Liam Proven <lproven at gmail.com> wrote:
>> They're all plastic pin grid array
>> packages. No heatsink at all. Nor does the datasheet for the PQFP show
>> anything related to a heatsink. It also shows a PLCC version; no heatsink
>> there either, and again I've never seen one. Maybe that's just because I
>> normally only saw them in Acorn machines, of course.
> You seem to misunderstand my remark about heatsinks.
> It is also possible that I am misusing the term "PQFP" but I have
> attempted to confirm it with Google image searches and I think it's
> what I meant.
> Is that not a PQFP chip? A flat plastic package with pins on all 4 sides?
PLCC and PQFP both are plastic packages with leads on all 4 sides. But PLCC specifically means a package with J-leads: the legs come out the package side, go straight down, and tuck under the package in a J-shaped curve. PQFP (and variations with similar acronyms) have "gull wing" leads: out the side, down to near the board, and then outward resting on the board.
SA110 is definitely PQFP. Here's a PLCC for comparison:
PLCCs have fairly limited lead counts; they were common for 44 lead packages, and perhaps a bit more. PQFP goes well over 100, especially in the "fine pitch" ones with lead pitch under 1 mm. (Pain in the *** to solder...) Beyond what those can do, or for extra small packaging, we get BGA -- ball grid array.
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