Differences

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--- decap:mech [2012/02/20 09:33] – created mcmaster
+++ decap:mech [2013/10/20 14:59] – external edit 127.0.0.1
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+====== Milling ======
+Live analysis decaps often mill the cavity first to reduce processing time and better control where the acid flows.
+Procedure:
+  - Ideally you'd x-ray the package to find out where the die is.  Alternatively make a guess or sacrifice an identical chip (ie from completely removing it from the package)
+  - Use a micrometer or similar tool to measure from the edges and score out a rectangle where the die should be
+  - Use a sharp flat tip bottom endmill to slowly cut down and create a pocket until just before the bond wires (or further if you don't care about taking it live)
+Tips:
+  * Consider creeping in a few mm past where the die actually is.  As you etch down it will eat out towards the sides
+  * If you have to apply any noticeable pressure your endmill is not sharp enough.  In this case it tends to creep downwards to give an uneven cut and may be difficult to use
+  * As a rule if thumb I cut down about a quarter of the package height
+====== Grinding ======
 Several groups have success with simply sanding the chip down using a Dremel or sandpaper.