moisture sensitive ICs?

Community PCB Design
1

I did one pcb design with AVR of TQFP type package. It was a failure. The design was sound, the PCB assembly was sound and all the possible error sources were eliminated. When I got the package, it was labeled moisture sensitive ICs and was recommended to be baked for 48 hours. I did not baked them for that long time. I baked them for just around 1 hour. After the reflow, the IC, on the outside seems ok and there is no apparent damage. Whatever damage has occured, it must be inside. Now my questions are:

Are there small packages like TQFP and similar types that are not moisture sensitive and thus you do not need to bake them?

If yes, how you identify them and ask for them?

Are all TQFP packages moisture sensitive?

How about QFN or SOIC packages?

All in all, what kind of packages are moisture sensitive?

Regards,

SMDfan

2

You only need to bake them if they have been out of the packaging for some time if they are being reflow soldered. The plastic encapsulation can absorb moisture, and the rapid heating of the package can cause it to crack or even explode. It doesn’t matter for manual soldering; I’ve soldered hundreds of chips, have never baked any of them, and have had no problems.