For all those, that follow the discussion from here or vaguely
remember some other rotations:
Rick Collins wrote:
I had to go through all this some time ago and recently I wanted to
iron out all the difficulties so that the assembly house could use
my XYRS file (location and rotation data) directly without alteration.
That ended up being a fool's errand, but I did learn a few things.
IPC has a standard for this which everyone "seems" to use. For two
pin symmetrical parts, pin one is to the left. For IC type parts,
pin one is in the upper left quadrant for parts with pin one in a
corner or for parts where pin one is in the center of a side pin
one is on the upper most side. This is the zero degree rotation
point for the part. All rotations are counter-clockwise from this position.
on 2010-08-15 Rick wrote in thread 'Specification of Rotations for
Auto Assembly':
"I just found something that changes what I thought I knew. I have
a PDF of an IPC magazine from 2005 where they are touting a "leap
forward" in land pattern generation. An illustration showing pin 1
in the upper left for SOT components is what I used as my
reference. That and the post in the FreePCB forum of a normally
very reliable source. But I found a copy of IPC-7351 and it clearly
says that for SOT and most other IC parts, the original rotation is
with pin 1 in the LOWER left. That is what FreePCB does in the
library editor by default. "
This isn't Ricks fault: reading the 2005 IPC-7351 I can confirm
this, while the 2009 IPC-7351B says,
that pin 1 is in the upper left corner ;-)
Shall I comment on this ? I'll just use upper left...