Prompted by Jami, but in a completely different thread & without shouting because
there seems to be some confusion over it (well here at least).
I have in fact been looking into component rotations as supplied by major manufacturers and what
the IPC-7351A says on pages 77-82, Section 16.
(shock horror - yes I do have the standard & have read "some" of it).
For instance, let us take a look at the SOT-23.
While the pin numbers may be the same, have a look at
http://www.fairchildsemi.com/products/discrete/pdf/sot23_1tr.pdf
This is by Fairchild, a big enough manufacturer don't you think?
Now perchance this one manufacturer could be wrong, I thought I'd better check another, so let's
have a look at National Semiconductor.
http://www.national.com/ms/MS/MS200164.pdf#page=6
Looking at the document, as the tape is fed into the P&P machine with the holes on the left.
The single pin is also on the left, this is zero rotation.
Yet the IPC-7351A spec has it shown 180 degrees out?
Why is that?
Have we been placing them 180 out all these years? they still seem to work. :-)
Either the standard is wrong, the manufacturers are supplying them wrong or we are looking at them upside down?
We tell our pick & place machines (Quads) that they are in zero rotation and they get them right.
I'm puzzled, please put me out of my puzzlement I'm only a noob.
Matthew.
(P.S. now if someone comes back at me and says "the spec is as reading from inside the machine" I shall
ask "where does it say that?" because it says its "as fed into the machine").
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