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--- invasive [2012/06/23 22:22] – created mcmaster
+++ invasive [2025/08/04 21:23] (current) – external edit 127.0.0.1
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 Invasive techniques actively modify the system in a permanent way.
+====== Backside analysis ======
+[[backside:start]]
 ====== Rewiring ======
-====== Cutting wires ======
+===== Cutting wires =====
-===== Laser =====
+==== Laser ====
 The "professional" mid range solution.  Typically some form of Nd:YAG, either the fundamental or some harmonic.  Expect minimum of a few thousand USD for a system, probably many more.  Probably the most economical would be to piece together a Mitutoyo microscope.  Of course, be careful not to look into your home spun laser while firing without good reason.
-===== FIB =====
+==== FIB ====
-The "professional" high end solution used for small processes.  Equipment is rather expensive. (how much?)
+The "professional" high end solution used for small processes.  Equipment is rather expensive. Some estimates seem to put them around an order of magnitude of 500,000 USD.
-===== Scratching =====
+FIB time can often be rented on an hourly basis from universities and research labs.
-Microprobes can cut traces by moving back and forth.  Professional units use ultrasound.
+azonenberg is beginning to experiment with FIB. [[azonenberg:fibnotes|Lab notes]]
-===== Chemical =====
+==== Scratching ====
+Microprobes can cut traces by moving back and forth.  Professional units use peizo's (ie ultrasound).
+==== Chemical ====
 By masking the chip and then etching (ex: with HF) wires can be removed.  Masking compounds range from photoresists to nail polish.
-====== Adding wires ======
+===== Adding wires =====
 Usually done with a fib.  Can be done temporarily with microprobes or possibly on a high process chip very carefully with conductive epoxy.
+====== Presentation: low cost microporbing ======
+JM's highlights from watching the presentation
+exposing wires
+  * laser
+    * expensive
+    * more reliable with experience
+    * better option for smaller areas
+    * better option for planar chips
+  * scratching
+    * good option for larger, non-planar chips
+    * lower cost
+fuses
+  * binary search by covering chip
+    * try to erase with UV light
+  * trace VPP
+    * charge pump or external
+  * confirm guess via microprobing
+op amp vs ttl amp for gain
+  * microcircuits damaged or distorted when disturbed
+  * op amp in volt follower mode
+    * "more transparent electrically"
+    * look at noise level
+      * drops when makes contact
+      * not necessarily the right wire though
+fib probing
+  * shoots ions instead of electrons
+  * filled hole with platinum to make a bond pad
+anti-anti-re
+  * cut charge pumps
+  * jump security mesh
+  * go from back side
+    * challenge: can destablize chips
+    * tends to be used more by FA than RE
+  * peizo probing
+    * they didn't like it
+    * I've seen others use it
+future/upcoming anti-re
+  * analog meshes
+    * The IBM PCI card thing has one externally but maybe not plausible yet at chip level
+No mention of masked etching.  Ex: putting PR or nail polish and etching with HF
+====== References ======
+  * Functional IC Analysis: http://nedos.net/host2012.pdf
+  * Breaking and Entering through the Silicon: http://nedos.net/ccs2013.pdf
+  * Low-Cost Chip Microprobing
+    * http://events.ccc.de/congress/2012/Fahrplan/events/5124.en.html
+    * http://media.ccc.de/browse/congress/2012/29c3-5124-en-low_cost_chip_microprobing_h264.html