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--- decap:epoxy [2018/02/28 02:43] – [CLC ControlLaser FALIT] mcmaster
+++ decap:epoxy [2018/02/28 06:55] – [A. Zonenberg etch rate measurement] mcmaster
@@ Line 149: / Line 149: @@
   * Practice on samples before trying something you care about
   * Puts off nasty fumes. Make sure to have good ventilation
+From Sam Wagner:
+  * "We use a yterrbium fiberlaser. What you are doing is trying to cause the plastic compound to explosively eject the silicon beads. So a pulsed laser is critical.  The laser melts the plastic and the pulse hopefully causes it to vaporize and eject beads."
+  * "Important to note that if you see silicon, you’ve destroyed the chip and can now no longer do FA work. We stop at the bond wires and use acid or plasma to remove the rest. Then it’s off to SEM or TIVA/LIVA or whatever you’re next step is."
 ===== jamiecraig =====
@@ Line 292: / Line 297: @@
-====== A. Zonenberg etch rate measurement ======
-FIXME: move this somewhere better
-Copper etch - 70 ml 3% H2O2 + 10 ml conc. HCl. Heat to 70C, agitate with magnetic stirrer.
-Test sample was Altera Stratix IV. Silver or tin plated copper. Plating was gone after <1 min in etchant, metallurgy of the plating was not studied. 20 minutes of etching = 0.13mm removal so 6.5 um/min. This number is likely +/- 30% or so because the temperature of the solution slowly increased over the etch period.
 ====== References ======