<![CDATA[Hello and welcome to this #nakeddiefriday installment.]]>Hello and welcome to this 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.

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]]>https://board.circlewithadot.net/topic/a5ca8999-e5b6-4700-a3e6-f83e04987727/hello-and-welcome-to-this-nakeddiefriday-installment.RSS for NodeFri, 10 Apr 2026 18:19:35 GMTFri, 27 Mar 2026 12:39:48 GMT60<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Tue, 07 Apr 2026 12:24:30 GMT]]>@azonenberg The same ROI on metal1. Just as mysterious.

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116363406239424761https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116363406239424761Tue, 07 Apr 2026 12:24:30 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Mon, 06 Apr 2026 12:41:30 GMT]]>And when you peel all that away... little sprockets.

(I know, I know.)

17/n

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116357810750219266https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116357810750219266Mon, 06 Apr 2026 12:41:30 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Mon, 06 Apr 2026 12:40:01 GMT]]>There have been a couple more intermediate steps captured:

http://infosecdj.net:8086/map/nxp/mp091a0/infosecdj_mz_nikpa60x_s5/
http://infosecdj.net:8086/map/nxp/mp091a0/infosecdj_mz_nikpa60x_s6/
http://infosecdj.net:8086/map/nxp/mp091a0/infosecdj_mz_nikpa60x_s7/

16/n

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116357804950668386https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116357804950668386Mon, 06 Apr 2026 12:40:01 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Thu, 02 Apr 2026 13:33:35 GMT]]>Processing is finished on the next step. Hit the metal over the logic blob almost perfectly.

Full-res map: http://infosecdj.net:8086/map/nxp/mp091a0/infosecdj_mz_nikpa60x_s4/

15/n

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116335366309866003https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116335366309866003Thu, 02 Apr 2026 13:33:35 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Wed, 01 Apr 2026 15:05:42 GMT]]>@infosecdj @azonenberg it looks like a tiny cat is reaching its paw down on the right hand side]]>https://board.circlewithadot.net/post/https://altelectron.org.uk/objects/e51a905e-bdbe-4a7f-ae68-1f3106d9c6d4https://board.circlewithadot.net/post/https://altelectron.org.uk/objects/e51a905e-bdbe-4a7f-ae68-1f3106d9c6d4Wed, 01 Apr 2026 15:05:42 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Wed, 01 Apr 2026 15:00:17 GMT]]>@infosecdj The outer seal ring is probably ground.

The fingered structure on the very edge of the die hooking to it looks more like an ESD diode than the mystery structure you showed above.

]]>https://board.circlewithadot.net/post/https://ioc.exchange/users/azonenberg/statuses/116330044980545877https://board.circlewithadot.net/post/https://ioc.exchange/users/azonenberg/statuses/116330044980545877Wed, 01 Apr 2026 15:00:17 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Wed, 01 Apr 2026 14:53:00 GMT]]>@azonenberg Hmm, a good guess. Though here is the same elsewhere on the die, the only connection I can see, or rather guess, is to metal-1 on the very outside of the die. I suppose we will see what happens when I get closer to m1.

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116330016282855469https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116330016282855469Wed, 01 Apr 2026 14:53:00 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Wed, 01 Apr 2026 14:44:14 GMT]]>@infosecdj Looks like some kind of multi finger ESD or IO drive transistor especially given the location near a bond pad, sure there's no vias up to the pad?

]]>https://board.circlewithadot.net/post/https://ioc.exchange/users/azonenberg/statuses/116329981809102212https://board.circlewithadot.net/post/https://ioc.exchange/users/azonenberg/statuses/116329981809102212Wed, 01 Apr 2026 14:44:14 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Wed, 01 Apr 2026 14:42:25 GMT]]>I am most intrigued by this set of cells not connected to anything else. Same cells found in groups elsewhere. Does anyone have an idea why is this here?

14/n

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116329974710620291https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116329974710620291Wed, 01 Apr 2026 14:42:25 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Wed, 01 Apr 2026 13:06:52 GMT]]>Die ID is now gone too. Always amusing how things just vanish without a trace.

13/n

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116329598972002071https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116329598972002071Wed, 01 Apr 2026 13:06:52 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Wed, 01 Apr 2026 13:04:19 GMT]]>The rest of metal-5 is gone from the centre, and a lot of metal-4 is now missing on the sides.

Full-res map: http://infosecdj.net:8086/map/nxp/mp091a0/infosecdj_mz_nikpa60x_s3/

12/n

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116329588936237751https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116329588936237751Wed, 01 Apr 2026 13:04:19 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Mon, 30 Mar 2026 08:46:44 GMT]]>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

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116317251455855822https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116317251455855822Mon, 30 Mar 2026 08:46:44 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Sun, 29 Mar 2026 13:16:13 GMT]]>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

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116312648780238159https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116312648780238159Sun, 29 Mar 2026 13:16:13 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Sun, 29 Mar 2026 08:45:39 GMT]]>One digit is gone from the maskset revisions. 🙂

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116311584900604233https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116311584900604233Sun, 29 Mar 2026 08:45:39 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Sun, 29 Mar 2026 08:41:29 GMT]]>The interconnect between metal5 an metal4 is mostly done with via banks, except for pad structures.

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116311568485197750https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116311568485197750Sun, 29 Mar 2026 08:41:29 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Sun, 29 Mar 2026 08:38:03 GMT]]>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/

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116311555047285268https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116311555047285268Sun, 29 Mar 2026 08:38:03 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Fri, 27 Mar 2026 13:07:29 GMT]]>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!

]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301289868101395https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301289868101395Fri, 27 Mar 2026 13:07:29 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Fri, 27 Mar 2026 13:06:06 GMT]]>Capacitors seem to be purple.

Also in the frame is one chonky resistor...

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301284430325756https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301284430325756Fri, 27 Mar 2026 13:06:06 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Fri, 27 Mar 2026 12:59:50 GMT]]>The green colours seem to be of poly resistors. The setup struggles to resolve them through all the layers.

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301259741095531https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301259741095531Fri, 27 Mar 2026 12:59:50 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Fri, 27 Mar 2026 12:57:17 GMT]]>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.

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301249724506597https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301249724506597Fri, 27 Mar 2026 12:57:17 GMT<![CDATA[Reply to Hello and welcome to this #nakeddiefriday installment. on Fri, 27 Mar 2026 12:50:57 GMT]]>Die ID marking in the corner lets us know this is an MP091A0, designed in 2021. 5 metal layers, all revision 1 it seems.

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]]>https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301224805170555https://board.circlewithadot.net/post/https://infosec.exchange/users/infosecdj/statuses/116301224805170555Fri, 27 Mar 2026 12:50:57 GMT