NSOP cause from Carbond layer

Guest

The EDX was performed on good and NSOP pad (5 keV). Both present a
peak of C and shown highly in die surface. So I'm not sure is C shall be considered as 1 factor of NSOP. //Tata

Joined: 20 Jun 2026 Posts: 76

Hi Tata,

'NSOP' means 'non-sticking on pad', right? First Q - why did you get a C peak in the EDX spectrum of your good pad? What's the composition of your bond pad? The EDX spectrum of most good bond pads only show Al or Al and Si. If your bond pads are not supposed to have C, then maybe it possibly came from a contam on the pad.

Pls do the EDX again at a slightly higher EHT. 5 keV is too low to make the pad emit many important peaks for common contaminants. I suggest that you also do the EDX at 7-10 keV. Experiment just to make sure you are not missing some peaks.

The 'good' bond pad that you're comparing to must not come from the same lot of your affected unit. It must be from a known clean lot, so you'll really know what the EDX spectrum of a good bond pad really is. Keep us posted.

Thanks,
FARel Engr

Guest

Thanks for your input. Forgot to tell you that actually I did at 10 kev, and peak of Al and Si has present. Anyway will find a good know die for doing
EDX then will compared with NSOP pad again // Tata