[gta02-core] Good news from Sao Paulo

[Werner Almesberger]

Good news ! Prof. Marcelo Knoerich Zuffo of the University of Sao
Paulo (USP) has offered gta02-core the use of his SMT facility. As if
this wasn't generous enough, all he asks for in return are a few of
our prototypes for his team to play with.

Here's a picture I took:
http://people.openmoko.org/werner/smt.jpg

Just kidding :-) This is just a manual rework station. Here's the real
thing:
http://people.openmoko.org/werner/smt-line-usp.jpg

There are three pick-and-place units with a total of about 200 feeders.
The long white thing at the end is a 12 zone lead-free nitrogen oven.

I'll upload some more pictures later today, when I'm back home.

Regarding PCBs, there are no PCB houses that are good at making this
kind of board in small quantities in Brazil, so the production team at
USP recommended that we look for a PCB maker elsewhere. If anyone has
a recommendation, please post it.

As a reminder, our PCB design parameters are 6 layers, 1 mm board
thickness, 5 mil track width and clearance, and ENIG coating. (USP had
some nasty experiences with cheaper coatings, and we wouldn't want to
lose half our boards to SMT problems.) 1 mm for six layers is a thin
board, which may drive the price up. 5 mil is also more demanding than
the 6 mil many mainstream PCB houses offer.

I also asked about whether we could use micro-vias under pads and
the production team promised me a response in a few days. Oh, and I
forgot to ask for a recommendation for a place that makes stencils.
I'll do so by mail.

We also owe a lot of gratitude to Jon "Maddog" Hall who brought me
in touch with Prof. Zuffo and who convinced him to support our
project.

- Werner