TPS82085: Issue with example board layout

Bailin Cao

Part Number: TPS82085

From the Land Pattern Example -SOLDER MASK DEFINED on page 19 of TPS82085 datasheets, the solder mask opening is smaller than the metal under solder mask. Is that correct? Thanks.

over 6 years ago

0 Chris Glaser over 6 years ago

TI__Guru*** 142750 points

Yes, this drawing uses solder mask defined (SMD) pads. Therefore, the soldermask controls the solder area, instead of the copper.

0 Bailin Cao over 6 years ago in reply to Chris Glaser

Expert 1120 points

Thanks Chris.

This is a little bit unusual. Normally, a solder mask is slightly larger than a copper land as most of TI parts .

0 Chris Glaser over 6 years ago in reply to Bailin Cao

TI__Guru*** 142750 points

That would be non-solder mask defined (NSMD). SMD is used a lot for power devices, which will have large planes connecting to the pins to carry the current and heat. SMD then provides better control of the amount of copper showing which gives better soldering.

Power management

Power management forum

TPS82085: Issue with example board layout