AM5728: How much pressure can the BGA balls take

Art Mecina

Part Number: AM5728

Hello Guys,

Good day.

Our customer have the following question on the maximum pressure the AM5728BABBCXA can handle:

1) The maximum pressure the BGA balls can handle both individually and uniformly? Do we have a document to support this?

2) What about the circuits, silicon items, others hidden under the stainless steel cover? Are they not affected with the maximum allowable pressure applied on top of the package

We found below e2e post but can you help confirm?

https://e2e.ti.com/support/processors/f/791/t/615253?AM5728-Heatsink-fastener-load-force#pi320966=2

Thanks to clarify!

Art

over 3 years ago

0 kcastille over 3 years ago

TI__Mastermind 49132 points

Art,

The AM572x device can sustain a uniform pressure of ~6 lb across the top of the package. If the pressure is not uniform, then the absolute worst case pressure on any single bga ball must not exceed 33 grams.

Regards,

Kyle

0 Art Mecina over 3 years ago in reply to kcastille

TI__Genius 16575 points

Hi Kyle,

Thanks for the information!

Is there an official TI documentation on this? The customer will need to add the related document on their PPAP documentation.

Art

0 kcastille over 3 years ago in reply to Art Mecina

TI__Mastermind 49132 points

Art,

There is no official documentation for this. This is our standard recommendation based on maximum pressure per ball.

Regards,

Kyle

0 Art Mecina over 3 years ago in reply to kcastille

TI__Genius 16575 points

Thanks Kyle!

I will inform customer about this. I might direct customer to this thread directly for further inquiries.

Best regards,

Art

0 kcastille over 3 years ago in reply to Art Mecina

TI__Mastermind 49132 points

Martin, As we discussed in email, the 33g spec is pulled from the same spec as Tom's post here:

https://e2e.ti.com/support/processors/f/791/t/615253?AM5728-Heatsink-fastener-load-force#pi320966=2

33g is the "worst case" spec for a single solder ball across all package types (>=0.65mm ball ***) and 20 years 100 degC. Since this force should be easy to achieve in practice I didn't want to overcomplicate things with the table that Tom provided.

6lbf (27.6N) is a heavily margined target for force spread across the top of the package, with the pressure distributed to the 760 balls of the SoC. If 6lbf is met then as long as you have reasonable planarity (uniform-ish force) then you should be well away from the 33g spec limit.

Regards,

Kyle

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AM5728: How much pressure can the BGA balls take