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Pads are rotated 90° compared to .dra file

SOT23

Hello !

I am facing a very strange problem : some footprints have their pads rotated 90° compared to what I did in the dra file :

This is supposed to be a 1210 chip capacitor

I have had this problem in two different occasions : 

- While quickplacing components on a new design, the pads where rotated 90°.

- While refreshing pads on a design that was already routed. I had to modify a padstack and refreshed all the pads. Big mistake... Now I have all my 1210 capacitor pads rotated.

Why is this happening ? This is very weird and very unwanted... Does anyone have a solution ?

I am using OrCAD Pro, 17.4 S029

Thanks

  • 0

    There is nothing like enough detail to resolve this but it's important to note that PCB Editor will be reading the PAD, Padstack, files directly from the PADPATH and NOT any Padstacks cached in the DRA file(s). This sounds like the Padstacks have been defined locally in the DRA file(s) and the actual PAD files being used have a different rotation specified for the Padstack. Another possibility is that there are multiple definitions of the Padstacks stored in the PADPATH and the order is getting a Padstack with the "incorrect" rotation selected. Try the Symbol Library Path Report and the Padstack Usage Report to get the file locations.

  • 0

    This may be issue how you defined the pads. Make sure for length you have given length, not width value & vice-verse. One of the design I previously worked was assigned with wrong values & it seemed pads rotated but that wasn't the case.

  • 0

    Hello SOT23,

    Even I had faced this issue. If your footprint (.dra) is correct then I assure you that you need not modify every 1210 capacitors individually. Instead please follow this step:

    1. Goto: Place/Update symbols.
    2. The "Update Module and symbols" window will pop-up
    3. Select "Package symbols" and the respective package (like the 1210 capacitor in your case).
    4. Select "Update Symbol Padstack from library"
    5. Click on refresh.
    6. All the capacitors with 1210 will be refreshed with the one with the library.

    Hope this works.

    Regards,

    Ravi

  • 0 in reply to RHC

    Thank you for the answer ! I tried that at that time but it didn't worked... I had to create a local copy of the symbol and shift it's pads 90°...

  • 0 in reply to oldmouldy

    Sorry for the late reply !
    To try to get the origin of the problem, I re-created the .dra and .pad, and the problem was still there. It seems that Allegro does not "remember" the pad orientation set in the .dra. What I mean is that if the padstack has 90° rotation (using move, rotate) in the .dra, when put in the design, that rotation doesn't get transfered. I think this is the case because this only happens with pads that are rotated. If a pad has a 0° orientation in the .dra, then there is no problem.

    Does it mean that I have to create all pads with correct orientation in the padstack ? It means that I can't use a padstack that is for instance a 1mmx2mm rectangle as a 2mmx1mm rectangle. I have to create 2 different padstacks...

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