TS3USB221A: TS3USB221ARSER/TI discoloration observation

Hi Liyang,

This question is probably best redirected to our Quality & Reliability team.  I can say that all of our parts go through extensive testing, and so any parts on the market passed those tests when they were delivered.  Could you let me know where and when you received these units, how long they were stored by your team?

Here is the qualification summary for the TS3USB221ARSER: Qualification summary

Thanks,

Nicholaus

Hi Nicholaus, 

TS3USB221ARSER/TI, with package 10-UFQFN, does discoloration apply to the TI Rough Pre-Plated Lead frame Technology introduced? If yes, could you please share with us the PCN and related document? 

Thank you! Application Note Single Side Rough Leadframe.pdf

Hi Winnce,

I have reached out to the packaging team for an answer, and I will follow-up in 24 hours.

Regards,

Nicholaus

Hi Winnce,

The packaging team requested the marking on the top of the device to confirm if rough pre-plated lead frame technology applies and also answer my original question about when they were received. 

They confirmed that the rough pre-plated lead frame would not explain the discoloration in the image; one possibility for the discoloration is "what we call Ag tarnish, and does not affect solder joint wetting or reliability on leadless packaging".  Once we have the top marking that will help confirm this.

Thanks,

Nicholaus

Thank you for your help. 

Please refer to below body marking photo of TS3USB221ARSER.  "Ag tarnish, and does not affect solder joint wetting or reliability on leadless packaging" could you please share with us the official document once it is confirmed?  Thank you!

Thanks,

I requested a document.  As soon as I receive a response, I will let you know.

Regards,

Nicholaus

Hi Winnce,

There is no official document that confirms that tarnish will not affect the result.  Considering excessive tarnish can be caused by storage conditions, we cannot make such a guarantee.  Here is more information about product storage: Product shelf life | Quality & reliability | TI.com

Regarding the Ag tarnish, I can only say that in all previous observed instances Ag tarnish has not affected solder joint wetting or reliability. 

Do you have a shipping label for these units?  Sorry, but the top marking isn't enough information to determine if these are rough pre-plated lead frame technology.

Thanks,

Nicholaus

Hi Winnce,

Will you be able to provide the shipping label?

Regards,

Nicholaus