TPS25947: Request the footprint file(CAD) of TPS25947.

Hi David,

Sorry for the inconvenience . I will get back to you by early next week.

Regards

Kunal Goel 

Hi David,

I am attaching the correct footprint .

Regards

Kunal GoelTPS25947-footprint.zip

Hi Kunal,

Thank you for providing the footprint.  I loaded it into Altium and I think the Solder Mask is incorrectly set to a manual expansion of 0 mm.  Per the datasheet it should be set to a maximum of 0.05mm (but non-zero in my opinion), or "Rule" if the project's design rules are set to 0.05 mm or less.  A solder mask expansion of 0 mm for Non Solder Mask Defined is unrealistic since it is nearly impossible to have perfect registration between the mask and copper layers.  The Solder Mask Defined recommendation is correct because it shows a minimum overlap of 0.05 mm.

Regards,

Greg

Thank you for your support.

You're welcome.  In case you're not familiar with how complex pads are created in Altium, here is a link to a PDF file that shows how it is done:

https://resources.altium.com/sites/default/files/uberflip_docs/file_1227.pdf

The odd-shaped pads in the corners of the TI footprint are a combination of a regular SMT pad and a region.  The pad is round and within the region.  Because the region overlaps the pad, it becomes an extension of the pad.  It is correct to set the solder mask expansion for the round SMT pad to 0.  If you look at the properties of the region, it also has settings for paste and solder mask expansions.  That is where you would set the solder mask expansion to 0.05mm (or less if your PCB fabricator can handle the tolerance, but not as small as 0 unless you want some solder mask on your pad).  The paste expansion in both the pad and region is set to a large negative number, which is how you remove the paste opening in Altium.  The paste features are explicitly drawn in the paste layer because they are slightly different than the pad.

Greg

In my first forum post in this thread, I said that the Solder Mask Defined recommendation is correct, but I didn't mean to imply that the Non-Solder Mask Defined recommendation is wrong.  The datasheet is correct, and I think the footprint needs some adjustments.

Greg

Hi Greg,

Thanks for pointing it out. I will get back to you regarding this.

Regards

Kunal Goel

Hi Greg,

Working with team for updating the footprint. I am closing thread for now. 

Regards

Kunal Goel

Hi Kunal,

Are you going to re-open the thread after you have some feedback?  I'm unsure why you are closing it.

Regards,

Greg

Hi Greg,

The thread automatically opens when someone post on this thread. You can always post anytime you want.

Regards

Kunal Goel