Differences

This shows you the differences between two versions of the page.

--- alliedhightech:start [2021/04/23 17:30] – mcmaster
+++ alliedhightech:start [2025/08/04 21:23] (current) – external edit 127.0.0.1
@@ Line 5: / Line 5: @@
 They make some nice machines.  I regret not buying one that was on eBay
-====== McMaster notes ======
+[[mcmaster|McMaster notes]]
-===== 2021-04-21 =====
-  * Goal: set RP2-B0 in wax on Allied sample holder
-  * RP2-B0
-    * Decapped 2x "live" from photo shoot to bare die
-    * Around 277 um thick. Later measurement 281 um
-  * Sacrificial dies
-    * Samsung k4h560438e-tcb0
-    * 324 um
-  * Area
-    * Samsung: 5.3 x 11.1 = 58.8 mm2
-    * RPI: maybe 4 mm2
-    * Net: maybe 60 mm2
-  * Etchant: 20% w/v KOH in water
-    * https://cleanroom.byu.edu/koh
-    * Approx 250 um / hour heated => 4.15 um / min
-  * Etch
-    * Etch 1
-      * 25 min @ 177F hotplate
-      * 306 um
-    * Etch 2
-     * 30 min?
-      * raised temp?
-      * 297, 302 um
-      * High spots forming (was warned might be uneven at this conc)
-    * Etch 3
-      * Now hotplate at 220F
-      * 286 um, 291 um
-      * 14 um in 30 min
-      * (286 - 277) * 2 = 18 more min?
-      * Lots of metal flaking off
-    * Etch 4
-      * 20 min
-      * Ultrasound. Lots of stuff flaked off
-      * Didn't note final thickness...
-  * Check all dies for thickness before mounting
-    * Not all started at exactly the same time, although was close
-  * Order replacement lapping gauge
-    * 543-452B, ID-C125EB
-      * 1 um resolution
-      * 25 mm travel
-      * Long
-      * Flat carbide tip. Will need to switch to new unit
-    * Skips
-    * Can't modify spares to be long enough
-    * One that might work I can't get to power up. Completely broken?
-  * Set in wax
-    * 0.4 mm gap in area(s). Not ideal but may still work
-===== 2021-04-23 =====
-Goal: setup lapping machine, lap RPI chip from other day
-TODO:
-  * Level head
-  * Review Allied recommendations
-  * Characterize um / rev
-    * Gauge skips, but is stable over say 1 mm
-  * Setup slurry feed
-    * Can I make this nicer?
-Inventory:
-  * 2x MultiPrep systems w/ arm
-    * Both were surplus / in bad condition
-    * One is more "ready to go"
-  * Lots of lapping disks
-  * Is my old colloidial silica still good?
 ====== Parallel polishing ======