need square aluminum electrolytics

[Jon Elson]

I have a pick and place machine that works great for
most parts. One I am having a problem with is aluminum
electrolytics. I think when the centering jaws center
the part, it can rotate on the nozzle. This machine
does not have vision, and the jaws only extend a
mm or two below the nozzle, so they miss the plastic
foot of the part.

Does anyone know of aluminum electrolytics with a squared-off
top so the alignment jaws will work?

I can use Oxi-Caps that are made in the same form factor
as tantalums, but they only go up to 6.3 V or so, so there
are some places I need to stay with the aluminum caps.
I prefer not to use Tantalum for a couple reasons.

I have looked in the usual distributor's catalogs without
finding anything except the round-top.

Thanks in advance for any help.

Jon

[Jamie]

back when I was at Semco doing the R&D on the pick and place mica
machine to assemble mica chip caps, we used a vacuum finger to pick up
the bits of mica and also a vacuum was present in the middle of the jaw
assembly that grabbed the encapsulated body after the UV process.

We had a small rubber foot with a small hole in it to seat on the
sheets for pick up..

Maybe on your machine you can insert a small rubber foot with hole
down the middle and can open and close a side port to release vacuums
when the jaws open and close ?

On our set up, we actually had a small needle valve port that would
insert some air pressure to quickly push the item away so that it would
not stick on the rubber foot to long. In your case, I don't think you
would need that, just a near by port opening to remove vacuum.

Jamie

[Jon Elson]

Well, the same heads are used for chip passives or small ICs in SO
packages, so the nozzle needs to be small enough that the aligning jaws
don't bump into the nozzle. But, the real problem is the jaws will
spin round parts to some extent, and I think O-rings on the nozzle
would not change that. What I really want is aluminum electrolytics
with some flats on the top, rather than a completely cylindrical body.

Next time I fire this up, I will try the head with no jaws, that shouldn't
make any rotation of the part, and the basic alignment of the machine
should be fine.

Jon