Oh, wow. Man, you are such a tease. :)
That wasn't a tease.. This is a tease :)
Hehe..
PPtk
I can actually SEE the dirty smile on your face right now!
Haha, That's great :) Look really closely into the 24 karat gold pads and you're probably right, I'm sure I'm reflected in one of them :-)
PPtk
For those who are intending on purchasing a DIY Kit, here is the assembly drawing - shows which part goes where. All of this information is on the Silk-Screen of the board, but I find it much easier to build when I can look at a reference (and possibly even make notes on it).
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PPtk
Pilot:
I'm in for this one: Cool white U2 Flux 1C Tint, fully assembled module. Can't wait to review this bad boy.
Just tell me where to send the Paypal and when.
Foy
I thought you were NeutraWhiteLovingFoy ? ?
Gold plating for solder pads can be a bad thing! Gold tends to form intermetallic compounds with lead/tin/aluminum (google "purple plague" for a well known example). These can be brittle and poorly conductive. Components have been known to fall of circuit boards...
He'll buy both versions anyway, we know the Foy, dont we? ;)
looking great Pilot, can't wait to see these in action.
About the programming - can the controller chips be supplied programmed off the board for self-assemblers or can they only be programmed after assembly using the pads on the board?
I am . . . but I'm going for lumens on this deal, or . . . will these neutrals be as bright as the 1C?
Foy
U2 Cool is going to be a bit brighter than a Neutral, but we are talking about 3 FULLY driven XM-L's. It's a lot of light no matter which exact emitter you choose.
I can supply them pre-programmed. It will be a no-cost option.
PPtk
The ENIG (Electroless Nickel, Immersion Gold) process has been perfected over the years, and solder joint quality on ENIG is excellent. "Purple Plague" is really a reference to brittle joints between aluminum and gold and is seen when gold is used inside of a chip package where a wire-bond takes place. Wire bonding and soldering are very different processes. "Black-Pad" can be a problem if electro-plated Nickel is used as the base, but circuit board finishes use electroless nickel to avoid that problem. Even NASA and the U.S. Military approve of the use of ENIG PCBs - And I promise that neither of those agencies would tolerate random components falling off of their assemblies. Components won't be falling off of these boards.
PPtk
These boards look so nice, I bet that fully assembled modules ,would be a real turn on (ok, that sounded a bit weird 
)
I'm so 
because I c'not afford something like this...
Purple plague is the aluminum-gold intermetallic. It is the most common/notorious. There are also gold-lead and and gold-tin intermetallics.
See the wikipedia article on gold plating. last section on soldering issues:
You are probably better off masking the gold from the component pads. There are also some indications that, under the right conditions, gold may help catalyze the formation of tin whiskers from lead-free solder. And gold can grow its own whiskers. But it sure is pretty...
Wikipedia is cute and all, but I think I'll reference something with a little more qualification..
NASA Jet Propulsion Laboratories, for instance..
http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/20708/1/98-1767.pdf
These are the conclusions after testing the way that solder joints fail on a variety of different component packages and a variety of different PCB finishes.
-------------------------------
Conclusions
For plastic packages, crack initiation, propagation, and failure occurred at either the package or
board interfaces for sections with or without voids. This was true for A or B cycle conditions.
Generally, voids were concentrated near the package interfaces. There appeared to be no crack
propagation among the voids, except for the voids interconnected at the interface.
For a ceramic assembly failure (See Comment Below), brittle failure was observed for Nickel-Gold surface finishes. OSP and
HASL showed ductile failure through eutectic solder joints. For plastic packages, there was no
distinction between the three surfaces
-------------------
The ceramic packages tested were very odd - from the document:
Ceramic packages with 625 I/Os and 361 I/Os were also included in our evaluation. Ceramic
packages had high melting solder balls (90Pb/lOSn) with 0.035 inch diameters. These balls were
attached to the 'ceramic substrate with eutectic solder (63Sd37Pb). At reflow, package side eutectic
solder and the PWB side eutectic paste was reflowed to provide the electro-mechanical interconnects.
---------------------------------
The high melting point solder is nothing like standard leaded or lead-free. It's VERY heavy in gold content. Nothing like that is used on the 3 XM-L Board
PPtk
I recently built some boards for the military and was expressly forbidden to use solder-on-gold. Also forbidden to use lead-free solder for that matter. In their environment, every little detail matters immensely. Things that don't matter in a benign, short life consumer environment can quickly turn into nasty problems. I can also show you some gold plated circuit boards out of some HP test equipment that failed because of the problem.
"HP" test equipment? I forgot - how long ago did HP Spin-Off the Agilent Line? 20 years? These problems are no longer problems. I have boards for military and aero-space companies (Boeing, Gulfstream, Bendix, Garmin, Marvin Land, General Dynamics, General Electric, etc) with ENIG all over them. It's been worked out, and it's now a trusted finish. Do some military branches still demand HASL - of course they do, they have no reason to change. Once they have a reason (they need 0402/0201 tech, they need fine-pitch BGA tech, etc), they'll investigate and then approve ENIG.
Here's another study by NASA-DOD.
It was really to investivate the usefullness of Lead-Free solders, but all the tests were done on ENIG and Immersion-Silver boards. These things were subjected to crash-scenario G-Forces. Every component survived a minimum of 33 events, and smaller components never failed.
Lead-Free solder is way more of a concern than ENIG boards will ever be.
PPtk
Edit: Agilent Spun Off in 1999. "HP" test equipment is at minimum 13 years old.
One of our Military customers uses these Honeywell HT Parts. They are an 8051 microcontroller that can survive 300C operating environments. Yes, that's 572 degrees F. Hot.
They're about 800 dollars each (the standard 8051 that they emulate is about 5 bucks).
Guess what their leads are plated with? Yep.. Gold.
PPtk