Dear Technos,

I know many of you, not only Steve Creswick and Wayne Thayer, have experience in microelectronics, so I dare poking you with this situation I'm having.

There's this Ka band MMIC die that was properly working in the beginning, only to see its performance degrading over time. Visual inspection revealed a strange discoloration running along all the metallized features and the glassivation is cracked here and there.

Please see image graciously placed by Stevie G on his website http://stevezeva.homestead.com/MMIC_Die.jpg

What during the assembly process could cause this kind of visual aspect?

Can this be a cause of the degrading performance?

Is it possible the die was like this from manufacturing (improper pre-glassivation cleaning or something)?

Any other impressions?

Thanks,

Ioan Tempea