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PICList Thread
'[Tech]PLCC Prototyping'
1999\12\09@213300 by Thomas Brandon

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I am looking at using a number of devices (CPLDs mainly) that are PLCC only
(at best). From searching the PICList archive I believe with a nice fine
soldering iron, flux and a bit of practice the PLCCs could be hand soldered
to a PCB. However, in prototyping I would far prefer to be able to
breadboard rather than having to make many prototype PCBs.

So, I would like devices that will allow me to breadboard with PLCCs of
44pins (minimum) hopefully all the way up to 84 pins. The best idea I can
think of is a small PCB with a PLCC socket in the middle (preferably ZIF but
due to cost maybe only LIF) and pin headers around the outside for
connecting to standard proto board. Now this shouldn't be too hard to
design, the problem is the construction of the PCB. I have little enough
experience doing non SMD scale PCBs so attempting a SMD scale PCB is not
neccesarily high on my list of priorities. Regardless any info on the
feasability of home producing SMD PCBs would be appreciated (i.e. how fine a
pitch can you manage?, what goes wrong with finewr pitch?, what equipment is
needed etc). But, for the moment I would prefer a premade PCB. Does anyone
know where such a PCB could be obtained and an approximate cost.

Oh yeah, and is it possible to do all this with a 100pin TQFP?

TIA,
Thomas Brandon.

1999\12\10@193819 by Mark Willis

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Lots of pre-made PLCC adapters out there;  Newark's catalog is handy, P.
609, has these for several SOIC packages, $1.39 to $6.49 in 1's.  And
for up to 20-pin PLCC's, $6.49.  Don't see any there for PLCC-44's.
Jameco has these with sockets for about $7, on looking more.  Many of
the SOIC units are designed for "sacrifice one, solder it to the board"
type work.

PLCC can be done at home by using 1-sided PC board and a "Sharpie"
marker, drawing the traces freehand, and then drilling through holes for
a .1" header of some kind & soldering IC/header onto the board.  If you
have shakey hands, good luck. <G>

(I didn't say it's EASY, you'll notice;  Expect to get Writers' Cramp
<G>  And expect to go through with a dental pick and clean up the
traces, as needed;  PLCC traces are pretty fine & close together, 25 mil
width on 50 mil centers, same as SOIC's.  {1 mil = 0.001" in my
terminology here.  I use mm for millimeters.))

http://www.pcdmag.com/resources/smt/ is a good place to look up pad
specs, BTW.

The Press'n'Peel type sheets can do these pretty easily, I imagine;
Need to get some & work with them.  For darn sure, the Phototypesetters
out there can make film for you that'll do this nicely!  Doing this with
tape and pad outlines on film then photoreducing can be done too, "but
why!?"  <G>

TQFP, that's 12 mil traces on 25 mil centers, get a magnifying glass if
you try this manually - lay off the Coffee, lay in a stock of Aspirin
too, and make an appointment with your massage therapist and
optometrist  <G>  As a 300 DPI laser has 3.33 mil pixels, that's 3 to 4
pixels wide, and should do OK with the Press'n'Peel type film.  A 600dpi
laser would be better here.

 Mark

Thomas Brandon wrote:
{Quote hidden}

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