Recently I wrote about my first experience with surface mount technology.  As part of that ongoing project, I needed a capable chip mounted on a development board.  That chip turned out to be an Atmega169 TQFP, which I will clock at 16Mhz.  To date, I'm still working only on single sided boards.  This would be my most ambitious project yet.

Like the last board that I made, I printed this one with a lithographic process.  The mask was printed on velum and then transferred to the positive sensitized board using a fluorescent lamp.



  Velum actually works surprisingly well.  It doesn't warp when printed, and holds toner quite well.  Even though this board is very basic, you can see that the routing is quite...

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