BQ25155: Underfill requirements for BQ25155 DSBGA (20)

Hi Bob,

It appears TI does not provide recommendations for specific underfills. We do offer these guidelines to help with the selection:

TI DSBGA products are designed and tested to ensure excellent board-level thermal cycling reliability without the need for underfill in intended applications. If a customer chooses to underfill a DSBGA product, TI recommends following the guidelines below to maximize reliability.

• The underfill fillet should extend partially up the die edges. Underfill that ends at the bottom (ball side) of the die will degrade reliability.

• The underfill should have a CTE closely matched to the CTE of the solder interconnect.

• The underfill should have a Tg above the expected maximum exposure temperature

You can read more about the package in this documentation. https://www.ti.com/lit/an/snva009ai/snva009ai.pdf 

Best Regards,

Juan Ospina