CC2651R3: Is it OK to have traces under QFN packaage

Vsevolod Elantsev4

Intellectual 2930 points

Part Number: CC2651R3

Hi team,

Please advice is it OK to have traces under QFN package between thermal pad and pads?

Please look to the picture (selected traces):

over 4 years ago

0 FI over 4 years ago

TI__Mastermind 21630 points

Hi,

Not if it is a 2-layer board. Layer 2 should be a solid ground under the device.

regards

0 FI over 4 years ago in reply to FI

TI__Mastermind 21630 points

Hi,

Also the trace between the thermal pad and pin pads is not recommended as it may result in unexpected behavior.

Regards,

+1 fredrikgk over 4 years ago

Expert 2170 points

I have seen this done several times for CC devices without any issues. While TI officially will not endorse it, I do not see any problems. Just make sure you have sufficient clearance to the pins and the ground pad, and of course make sure there is no chance of your trace making contact with the ground pad of the IC.

0 Vsevolod Elantsev4 over 4 years ago in reply to fredrikgk

TI__Intellectual 2930 points

Hi Fredrik!

Thank you for honest answer.

I found that the trace between pads and ground pad could made layout easier and more consistent ground plane on bottom layer for 2 layer boards.

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CC2651R3: Is it OK to have traces under QFN packaage