Mastodawn

Hello and welcome to this #nakeddiefriday installment.

Today's guest is an NXP chip for which I do not have the part number in memory. The chip was used as a training target for the sample preparation tutorial section by Chris Pawlowicz of TechInsights at HARRIS'26, in which I had the pleasure to participate. I have an intact sample which I plan to deprocess at home during the coming days and hopefully apply all I've learned there.

Full-res map for you to explore: http://infosecdj.net:8086/map/nxp/mp091a0/infosecdj_mz_nikpa60x_s0/

Image taken using Nikon PlanApo 60x/1.40, 3260 focus-stacked tiles of 21 individual shots.

#electronics #reverseengineering #microscopy

1/n

Die ID marking in the corner lets us know this is an MP091A0, designed in 2021. 5 metal layers, all revision 1 it seems.

2/n

While I don't know the specifics, the device certainly has 6 functional units of the same type distributed along the 3 out of 4 edges. The top right corner houses 3 instances of a different unit, along with at least two more of a yet different one. And if memory serves, the centre was occupied by a blob of digital logic.

3/n

The green colours seem to be of poly resistors. The setup struggles to resolve them through all the layers.

4/n

Capacitors seem to be purple.

Also in the frame is one chonky resistor...

5/n

Next up is removing the top metal layer, which if memory serves is a thick 3um one. Thread will update when that's done.

Until then, I wish you all a great Friday and the weekend too!

6/n

Here we go. Metal5 was removed except for the central area; it was rather stubborn and didn't want to go. I will work on it a bit more and take another shot, need to be careful as metal4 started going on the edges already.

Full-res map: http://infosecdj.net:8086/map/nxp/mp091a0/infosecdj_mz_nikpa60x_s1/

7/n

The interconnect between metal5 an metal4 is mostly done with via banks, except for pad structures.

8/n

One digit is gone from the maskset revisions. :-)

9/n

After a bit more work. This is imaged using a dry objective.

Planarity is shit but no visible scratches, which is amazing.

Materials used: Allied 0.3u alumina suspension, Ted Pella Met-X cloth

10/n

The same in oil immersion. All the interference colours gone, and there's slightly more contrast.

Full-res map: http://infosecdj.net:8086/map/nxp/mp091a0/infosecdj_mz_nikpa60x_s2/

11/n

The rest of metal-5 is gone from the centre, and a lot of metal-4 is now missing on the sides.

12/n

Die ID is now gone too. Always amusing how things just vanish without a trace.

13/n