X-Authentication-Warning: delorie.com: mail set sender to geda-help-bounces using -f Message-Id: <201612162206.uBGM5xJ4000437@delorie.com> X-Recipient: geda-help AT delorie DOT com X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9 Date: Fri, 16 Dec 2016 17:05:11 -0500 To: geda-help AT delorie DOT com From: rickman Subject: Re: [geda-help] Orientation of components in X-Y (centroid) files Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="=====================_1306151890==.ALT" X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - sc110.eboundhost.com X-AntiAbuse: Original Domain - delorie.com X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - arius.com X-Get-Message-Sender-Via: sc110.eboundhost.com: authenticated_id: aarius DOT direct AT arius DOT com X-Authenticated-Sender: sc110.eboundhost.com: aarius DOT direct AT arius DOT com X-Source: X-Source-Args: X-Source-Dir: Reply-To: geda-help AT delorie DOT com --=====================_1306151890==.ALT Content-Type: text/plain; charset="us-ascii"; format=flowed Don't ever assume the assembly house will fix a bad XYRS file. I had an error in this data for IC packages which were *very* clearly marked on the silkscreen and they assembled them all wrong on that side of the board. For devices where pin 1 is on a corner, I believe the convention is for pin 1 to be in the upper left quadrant at 0 degrees. For components with a single row of pins, the pin 1 should be to the left. The orientation for parts on the bottom of the board should be as viewed through the board from the top. Rotation is counterclockwise for top side components and clockwise for bottom side components. From http://circuitsassembly.com/blog/?p=1787 "IPC says that zero orientation for two pin passives is horizontal, with pin one on the left. For polarized capacitors, pin one is (+). For diodes, pin one is the cathode. They note that pin one is always the polarity mark pin or cathode. Pin one is also on the left for resistors, inductors and non-polarized capacitors" Here is a more complete reference... https://www.screamingcircuits.com/assets/pdfs/understanding-the-centroid.pdf Make sure you download this file directly from Screaming Circuits as they had produced an older version of the file that had the rotation info wrong. It may still be available from some places on the web. Rick On 12/16/2016 4:10 PM, DJ Delorie wrote: >This is something typically "fixed" by the assembly houses that know >which way the parts are on the tape and reel, but... > >PCB uses pin 1 (and sometimes pin 2) to determine the angle. IIRC there >are specs for how to determine angle too, but I don't remember what they >are. > --=====================_1306151890==.ALT Content-Type: text/html; charset="us-ascii" Don't ever assume the assembly house will fix a bad XYRS file. I had an error in this data for IC packages which were *very* clearly marked on the silkscreen and they assembled them all wrong on that side of the board.

For devices where pin 1 is on a corner, I believe the convention is for pin 1 to be in the upper left quadrant at 0 degrees. For components with a single row of pins, the pin 1 should be to the left. The orientation for parts on the bottom of the board should be as viewed through the board from the top. Rotation is counterclockwise for top side components and clockwise for bottom side components.

From http://circuitsassembly.com/blog/?p=1787

"IPC says that zero orientation for two pin passives is horizontal, with pin one on the left. For polarized capacitors, pin one is (+). For diodes, pin one is the cathode. They note that pin one is always the polarity mark pin or cathode. Pin one is also on the left for resistors, inductors and non-polarized capacitors"

Here is a more complete reference...

https://www.screamingcircuits.com/assets/pdfs/understanding-the-centroid.pdf

Make sure you download this file directly from Screaming Circuits as they had produced an older version of the file that had the rotation info wrong. It may still be available from some places on the web.

Rick

On 12/16/2016 4:10 PM, DJ Delorie wrote:

This is something typically
"fixed" by the assembly houses that know
which way the parts are on the tape and reel, but...

PCB uses pin 1 (and sometimes pin 2) to determine the angle.  IIRC
there
are specs for how to determine angle too, but I don't remember what they
are.

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