FCDEV3B update

[Mychaela Falconia]

Hello FreeCalypso community,

I am pleased to announce that as of about 16 hours ago, the FCDEV3B
PCB fabrication process is now underway.  I have settled on using the
selective surface finish combination (OSP for SMT pads, ENIG for
plated through holes), which appears to be the standard used by the
cellular industry.  More precisely, I don't know what the cellular
industry uses *today* for their 3G/4G stuff and for "modern" GSM/2G
chipsets from MTK or Spreadtrum, but at least the OSP + selective
Ni/Au finish *was* the cellular industry standard in the days of
Calypso and Calypso+ chipsets.  Neither I nor Harald Welte have been
able to find out *why* the industry does or did it this way, but the
historical fact is that this practice has been very consistent for
both production and prototype board runs, hence doing likewise for our
boards is the safest choice.

In any case, the FCDEV3B PCB fab process is now underway, and the bare
PCBs are expected to arrive some time in mid-to-late February.  The
next steps are:

* While the PCBs are being made, we need to get the BGA reballing of
  Spansion flash+pSRAM chips started in parallel.  Being opposed to
  RoHS as a matter of principle, I am going to have our boards
  assembled with traditional SnPb solder paste, using a reflow
  soldering process at the lower temperature appropriate for SnPb,
  *without* subjecting our boards and their components to the crazy
  high heat of RoHS reflow.  For the other 3 BGAs I got parts with
  SnPb solder balls, but the Spansion part could only be obtained with
  RoHS solder balls.  The latter won't melt properly with a lower
  temperature SnPb reflow process, hence they need to be reballed.
  This reballing process can be done in parallel with PCB fabrication,
  and the remaining balance in the FreeCalypso account after the PCB
  fab order should be sufficient to cover this reballing - I just need
  to get back in contact with the people who told me they could do it
  (back in the early summer) and get the ball rolling.

* Once we have the PCBs and the reballed flash+pSRAM chips, we'll be
  ready to go into assembly - I already have all other parts physically
  on hand.  I don't know yet whether or not we'll need additional funds
  at that step - I will need to have another discussion with the SMT
  assembly shop about costs when we get closer to it.

Hasta la Victoria, Siempre,
The Mother