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--- cleaning [2013/11/17 07:15] – mcmaster
+++ cleaning [2025/08/04 21:23] (current) – external edit 127.0.0.1
@@ Line 166: / Line 166: @@
 Shame on you if you picked up a die with your bare hands but things do happen.  Acetone does not clean off fingerprints very well but soapy water does.  The above picture was taken after putting a fingerprint on a slide and sonicating in acetone for a few minutes.  It has little to no effect.  Fingerprint oils do not respond to polarized light (ie will black out).
-===== Polymide passivation =====
-Can be removed with strong acids (eg RFNA).  Still, does not come off easily so other methods should be researched.
+===== Polyimide passivation =====
+General reccomendations:
+  * Oxygen plasma is probably best if you have access to it
+  * If you can deal with safety issues, ethylendiamine may be next best
+  * Fuming nitric aicd works but takes a while.  This can potentially cause chip damage but shouldn't hurt Cu/Al if you keep the concentration high
+  * Piranha eats it quickly but it eats other metals nearly as quickly so its probably best avoided