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I am generating files for manufacturing my design in Altium 22 and ordering through Eurocircuits.

What I noticed during the ordering process is that the rotation of many components (and sometimes the position) is incorrect. Most often, a component will be rotated by 90 degrees off of what it should be.

I tried to track this problem down but it is unclear where it is coming from. The footprints are correct, and the 3D bodies are also aligned correctly. What could be the issue here and how can I fix it so my pick & place file is correct?

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  • \$\begingroup\$ Are you doing the P&P yourself or is an assembly house doing it? If the latter, liaise with them and ask if this is going to be a problem for them. If they say yes, update the question... \$\endgroup\$
    – user16324
    Commented Jul 25, 2022 at 12:14
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    \$\begingroup\$ @user_1818839 it will be done by the CB house and I have fixed the issue using their tools. \$\endgroup\$
    – Mu3
    Commented Jul 26, 2022 at 6:24
  • \$\begingroup\$ I was pretty sure they would have a way to fix it. \$\endgroup\$
    – user16324
    Commented Jul 26, 2022 at 12:34

3 Answers 3

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As far as I can make out, the rotation is based on the assumption by Altium that the way the component’s footprint was drawn is the same as the orientation in the tape (or waffle tray etc). After all, that’s all that Altium has to go on.

To the best of my knowledge the position is based on the centre of the part, but again this is an educated guess by Altium as the pads, 3D models etc may have different geometries.

For my p&p setup, 0 degrees means that the part is picked up from a (left-to-right) tape or a tray and is placed without rotation. If you know how the parts will be delivered it’s fairly easy to visualise what rotation is appropriate.

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  • \$\begingroup\$ This sounds like a reasonable explanation to me. Now that I think of it, I generated most footprints as if they would be "fed" from the top of the screen. What is interesting is that for the most part, I used the Altium footprint wizard - I would imagine it would have some feature related to proper orientation built in. \$\endgroup\$
    – Mu3
    Commented Jul 25, 2022 at 11:12
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Be consistent in your footprint library with pin 1 (Top-left and trend is now going bottom-left) and supply a top/bottom assembly printout with easy to recognise pin 1 location / polarity marking. This marking is most important to be clear. Preferably not under the component (visual inspection).

Usually they will check the files and get back to you in case of any issues. In case of Eurocircuits read this:

Eurocircuits design guidelines

An example from my lib, I always make them myself:

enter image description here

Clear marking in purple of the assembly center location and pin 1 (stumped corner). I use a delicate overlay sign, the one lower left is different to indicate pin 1.

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  • \$\begingroup\$ Most footprints in my library are generated through the footprint wizard and have pin 1 on the top left as well as the marking. I suppose that Eurocircuits expected pin 1 to be bottom left - I didn't actually see any information about that on their website. I did have proper pin 1 markings though so it was not hard to fix the rotations. \$\endgroup\$
    – Mu3
    Commented Jul 26, 2022 at 6:33
  • \$\begingroup\$ Do you have a pic? \$\endgroup\$
    – RemyHx
    Commented Jul 26, 2022 at 6:46
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properties of the component shows rotation 0, the pick and place rotation 90 degrees. so it looks like Altium issue John, Monbulk

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