AM4378: Pad size

Amarnath Murugadass

Part Number: AM4378
Other Parts Discussed in Thread: TMDXSK437X, TMDSEVM437X

Hi Sir/Madam,

What is the recommended pad size required to be used for AM4378? In eval board we see a pad size of 11mil is provided can the same be followed in our design to have flexibility is routing.

Regards,

M Amarnath

over 4 years ago

0 PaulM over 4 years ago

TI__Mastermind 28215 points

Amarnath

Please take a look at the post linked below. It has a couple of documents that you should answer your question.

e2e.ti.com/.../944882

--Paul

0 Amarnath Murugadass over 4 years ago in reply to PaulM

Intellectual 480 points

Hi Paul,

In the provided post they asked to refer theTable1 of the document spraca4 in which for 0.46mm (18.11 mils) dia ball (maximum dia size of AM4378 BGA ball) it is recommended to use 0.35mm (13.77 mils) dia pad size in PCB. But in the Eval board we see a pad size of 0.28mm (11mils) being used. Is it okay to use the same in our design. Please confirm

Regards,

Amarnath

0 PaulM over 4 years ago in reply to Amarnath Murugadass

TI__Mastermind 28215 points

Amarnath

I am going to ask a colleague to comment, but he is out of office until Monday. However, given the above are recommendations, if your assembly house has the capability, then It should be ok to use the smaller diameter.

--Paul

0 Shriram Moharil over 4 years ago in reply to PaulM

TI__Expert 4490 points

Hi Amarnath,

Can you clarify which eval board design you are referring to that uses the 0.28mm land pad diameter?

regards,

-Shriram

0 Amarnath Murugadass over 4 years ago in reply to Shriram Moharil

Intellectual 480 points

Hi Shriram,

We are referring to the General Purpose Eval board (TMDSEVM437X) and Starter Kit eval board (TMDXSK437X) of the AM4378 process.

Regards,

M Amarnath

0 Shriram Moharil over 4 years ago in reply to Amarnath Murugadass

TI__Expert 4490 points

Hi Amarnath,

Ok. Thanks for the clarification.

regards

-Shriram

0 Shriram Moharil over 4 years ago in reply to Shriram Moharil

TI__Expert 4490 points

Hi Amarnath,

We would recommend sticking with the recommended pad size for a production board design. The mismatch in pad size between AM437x and the board can create a solder joint that is not robust due to non-uniform distribution of solder. Therefore it is best to stick with the standard NSMD pad size as recommended in the IPC table.

regards,

-Shriram

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AM4378: Pad size