Timeline for Remove/exclude exposed pad of QFN package from PCB layout
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| Mar 8, 2020 at 20:00 | comment | added | abomin3v3l | @ThePhoton Thanks for help! I already have a prototype of the current circuit (with greater dimensions), and I can afirm the microcontroller does not heat anything, it runs 'cold' with package temperature very close to the ambient temperature. And now I will try to make a smaller layout. I will try dual layer PCB without the pad on the layout. Actually I will draw a very small pad in case it be necessary to connect the exposed pad to GND, but a very small one, not 2.8x2.8mm complete size... | |
| Mar 8, 2020 at 19:35 | comment | added | The Photon | @abomin3v3l sorry, but that doesn't mean the thermal resistance in the datasheet assumed no thermal pad connection. A microcontroller could easily be low enough power not to need the thermal pad, but it's going to be difficult to prove it from information in the datasheet. | |
| Mar 8, 2020 at 19:28 | comment | added | abomin3v3l | @ThePhoton For example, in a past project I did used an analog switch IC, part number FSA2567MPX, package "16-WFQFN Exposed Pad". I have left the exposed pad floating on the PCB layout, and the project worked well. | |
| Mar 8, 2020 at 18:07 | comment | added | The Photon | The datasheet thermal resistance almost certainly assumes the thermal pad is used. | |
| Mar 8, 2020 at 15:30 | comment | added | abomin3v3l | Well noted. I yet have the doubt if the exposed pad can be left floating or if it needs to be connected to GND. | |
| Mar 8, 2020 at 15:15 | history | answered | Marcus Müller | CC BY-SA 4.0 |