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  1. #1
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    Reason of measurements of Cap 1812 footprint

    Hello everyone,

    Here is a 1812 (4532 metric) SMD Cap: https://www.digikey.es/products/es?k...=445-1607-1-ND

    If one goes to the footprint provided by UltraLibrarian as follows: DigiKey link --> Download from UltraLibrarian --> Detailed view in the Footprint, we see the following:

    Click image for larger version. 

Name:	C1812.png 
Views:	10 
Size:	5.1 KB 
ID:	147723

    Pointed with the arrow shows that half of the pad=0.203mm

    According to IPC-7531, the pad should be 1.6mm (maximum) or 1.2mm (minimum).

    Can anyone provide me the reason why UltraLibrarian is using a lot less of pad width ? Are they mistaken ?

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  2. #2
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    Re: Reason of measurements of Cap 1812 footprint

    Are you sure you have attached the correct snapshot ?
    The picture is from an IC, but the link refers to an SMD capacitor.
    --------------------------------------------------------------------------------------------------
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    Re: Reason of measurements of Cap 1812 footprint

    Yes, I have attached DigiKey link and instructions to get to that information. You can check it. It is correct and very weird !



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    Re: Reason of measurements of Cap 1812 footprint

    Ops, my fault, you are correct.
    There is a big error in the size.
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    Re: Reason of measurements of Cap 1812 footprint

    There is a big error in the size.
    O.K. So it is an error.

    I don't want to provide the altium files because you would say I have corrupted the file. I want you you guys to check it.

    Here is step by step:
    From DigiKey link --> Click on "Download from UltraLibrarian" --> follow this video

    What you get in Altium footprint is exactly what you see on the "Detailed view" on the Footprint from UltraLibrarian, like here:
    Click image for larger version. 

Name:	link.png 
Views:	6 
Size:	41.2 KB 
ID:	147724



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    Re: Reason of measurements of Cap 1812 footprint

    It is not clear by whom the models available on the Ultralibrarian are made (is it from colaborative repository among manufacturers? are made by Digikey staff itself?). So far I have had no problems with even more complex ICs, but maybe it is time to review the feasibility of this site as a trustable source of footprint models.

    - - - Updated - - -

    BTW, I have used this site to get my Altium models, even reaching the monthly quote.
    I've used exactly the same process described in the video.
    --------------------------------------------------------------------------------------------------
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    Re: Reason of measurements of Cap 1812 footprint

    It has been stated on several occasions, get familiar with IPC-7351.

    I am a professional PCB designer for over 30 years now and i never download footprints from the internet. Learn the IPC-7351 standard and create your footprints
    accordingly. I know it is tempting to download them and may be OK for hobby projects, but thats it. (imho)


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    Re: Reason of measurements of Cap 1812 footprint

    Quote Originally Posted by senilicus View Post
    Learn the IPC-7351 standard and create your footprints
    accordingly.
    I am downloading the footprints for the 3D model, not the 2D.
    How do you make 3D model for this caps ? Or you do not need 3D models either ?



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  9. #9
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    Re: Reason of measurements of Cap 1812 footprint

    We use Library Expert for our footprints. It will also generate a 3D model. (if you have the license)


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