Re: pick 'n' place machines (was: OT 0805 resistor noise)

On Thu, 8 Sep 2005 08:06:52 -0700, "Walter Harley"
<walterh@xxxxxxxxxxxxxxxxxxxx> wrote:

>"John Larkin" <jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
>news:nbouh15hvlbnmq78qemji9qvsmtdt2vf9e@xxxxxxxxxx
>> See pics in abse.
>>
>> Cecily is assembling a board now, so I asked her about the flip thing.
>> So she just hits the side of a resistor, in the feed bin, with the
>> pickup tool, and it flips over; "just like playing tiddly-winks" she
>> says.
>
>Thanks, John. Great pictures. I'll show those to my current p&p machine
>(aka my wife).
>
>We do the same thing Cecily does, only with tweezers and a magnifying
>headset. It is just like tiddlywinks. But I worry about the possibility of
>damaging the part. And, as with tiddlywinks, if you're not careful the part
>goes flying somewhere... that's a big problem if it's a capacitor, because
>if it lands amidst a bin of other-valued capacitors there's no way to tell
>it apart. We're very careful to only work with one value at a time, for
>that reason, but it slows us down.
>

We do have an older, completely non-computerized, pantographic sort of
manual p&p that cost a few K. It just helps pick up and place the
parts... it has a vacuum pickup/rotation thing that rides on x-y
rails. They still use it sometimes for doing small boards. It's still
a lot better than placing parts with tweezers.

Of course, any p&p needs to be used with a board that has stenciled
solder paste. If you're hand-soldering, you need to place and solder
one part at a time.

We recently did our first 456-pin BGAs... and it worked!

John

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