Differences

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

--- equipment:lapping:type [2014/10/23 02:56] – mcmaster
+++ equipment:lapping:type [2015/06/30 16:05] (current) – [Platen] mcmaster
@@ Line 121: / Line 121: @@
     * Cast iron
-    * Diamond
+    * Diamond, Al oxide, etc film surface
     * Poromeric pad
-However, cast iron and diamond are too abrasive for IC RE and so only polymeric pads are typically used.
+Cast iron and diamond is generally too abrasive for IC RE.  Poromeric pads are standard issue and some Al oxides look suitable.
-Some machines can take magnetic apds such that one can switch, say, between a diamond and cast iron pad.  As you should really only be using polymeric pads this feature will probably be less useful.
+Some machines can take magnetic pads such that one can switch, say, between a diamond and cast iron pad.  If you are only using poromeric pads this feature will probably be less useful but could be if you are using films.
-{{gallery>:tutorial:lapping:layers.jpg}}
-Above: typical stackup seen on JM machine consisting of (top to bottom):
-    * MTI 8" Poromeric Polishing Pad (PSA) for final polishing - EQ-PP-8PSA-PC
-    * Two 8" Mater Plate ( Backing Plate ) for PSA Diamond plate, Sand Paper & Polishing Pad - EQ-MBP-8-2
-    * CrystalMaster 8 master lap
-The first, the poromeric pad is the most important.  It is essentially a soft pad to move abrasive around without actually scratching the die.  The next forms a smooth surface on which the poromeric pad rests.  Finally, the master lap is the interface to the machine itself and has ridges to keep backing plate in plate.
-Originally the machine had a steel backed diamond pad directly on the master lap (attached with adhesive, removed with acetone + heatgun).  In this setup the steel backing is much stiffer than the polishing pad and so serves as the backing plate.
 ==== Cast iron ====