PCB road-kill

Have you read about the polyimide? Here's the link for the article profma.com

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foxtail, thanks for the tip about the Flux Finish, my buddy John just asked about getting products into Europe and I told him some people favor gold immersion since it cannot be mistaken for Sn/Pb solder. This looks like another way to have that different look but I am sure it must cost less. And Mr Chibnik, thanks for a really perceptive comment. In addition your comments on companies vendors is good too. In my experience any competitor has bought the entire system and stole the source code so some analog guy like me posting the PCB should be more valued for marketing than feared for IP protection. If they gripe I will certainly take down the pictures since I am a nice guy, even though the post is a clear case of fair use.

DDW asked if it was haz waste. I'd say definitely no if it were lead-free solder on the pads and "probably not" if it were tin-lead solder, nevertheless it is something that should be recycled. I did notice one other error in your write-up (I previously said only one): etching outerlayers (and usually innerlayers as well is done by an alkaline ammonia solution, not by acid. I can see a date code of 4306 (43rd week of 2006) on the middle board in the top picture but any fab identifier is too blurry to make out.

I qwould want to know the manufacturer as well. I would be a little upset if my board waspickedup in the street by a competitor. Can determine all kinds of things from the board.

The cool looking footprints appear to be for two "Arrayed-Wavelength Grating"s. These can combine or split light - thus the MUX & DEMUX in the silkscreen.

you got everything right except one thing - the tooling holes in the corners are not used for aligning the layers during lamination - they were likely drilled during the routing step when the board was routed out of its panel. The lamination tooling holes are in an area of solid copper at the midpoint of each panel edge, with one hole offset slightly to prevent laying up the innerlayers in the wrong orientation (the so-called Multiline tooling system). Those holes are punched, not drilled, into the layers individually by a machine that aligns the holes based on the copper patterns after etching and is therefore called a post-etch punch. They are often a circle with flats on both sides. After lamination, if some epoxy (or polyimide, etc. depending on the type of prepreg used) flows out around the holes they might have to be spotfaced or drilled. This would be a big problem if the layers didn''t have solid copper around these holes, causing a high pressure area to drive the epoxy away from them. From all this discussion, it may sound like I was a PCB lamination engineer or something. OK, I admit it.

Well, I would think that when viewed from above, it probably indicates the optimium landing zone for alien spacecraft. Otherwise, it is a very interesting footprint.