Differences

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

--- carrier:start [2013/11/16 07:50] – mcmaster
+++ carrier:start [2013/11/16 08:00] (current) – mcmaster
@@ Line 16: / Line 16: @@
 Bare silicon chip without a package and affixed directly to the circuit board. Use in cost sensitive (ie cheap) applications. Above is probably from a commodity wrist watch.  There seem to be two types:
   * Epoxy blob (below type): die is placed on board, bonded, and then covered with a blob of epoxy.  The most common type
-  * Upside down dies (above type): likely WLCSP with underfill.  Basically a BGA where there is no encapsulant on the die and solder balls are attached directly to bond pads
+  * Upside down dies (above type): likely WLCSP with underfill.  Basically a BGA where there is no encapsulant on the die and solder balls are attached directly to bond pads (see BGA below for example of this sort of thing)
   * Flexible circuit: these are common in the line drivers on LCD screens
@@ Line 49: / Line 49: @@
 ===== Flip chip =====
-A package where the die is mounted upside down.  Usually this implies BGA or similar package.  Example BGA on a ceramic substrate...
+A package where the die is mounted upside down.  Usually this implies BGA or similar package.
+==== Ceramic BGA example ====
 Had thermal paste to improve conductivity:
@@ Line 57: / Line 59: @@
 After cleaning:
-{{:carrier:xpc7455:package_top.jpg?300}}
+{{:carrier:xpc7455:package_clean.jpg?300}}
-When solder balls are removed on the bottom looks like this:
+When most solder balls are removed on the bottom looks like this:
 {{:carrier:xpc7455:package_bot.jpg?300}}
@@ Line 75: / Line 77: @@
 {{:carrier:xpc7455:die_some.jpg?300}}
 {{:carrier:xpc7455:die_some_closeup.jpg?300}}