Chip in a QFN Package

[mawyatt]

I've been evaluating a new vertical macro setup and used an old test chip I had designed back in 2010 as a test subject. This chip is called DD2A (Direct Digital to Antenna, see patent 7903016 for those interested), fabricated in IBM9HP SiGe BiCMOS, and QFN packaged. I made no attempts at cleaning up the test subject chip, just used as is with lots of debris, especially around where the QFN package lid was removed (adhesive).

I used a WeMacro rail and Vertical Stand, with a Nikon D800E, Nikon 200mm F4 tube lens with a Mitutoyo 5X objective. Flash diffusion is with a foam cup since I'm not dealing with solder balls, and initially I used 4 speed lights located right up next to the cup. After dealing with the batteries dying, I switched to strobes and used 3 with 7" diffused reflectors located close to the cup.

Lens creep bit me with the 200mm, as the stacking showed some strange out of focus jumps which I wasn't sure what was going on. After many hours and a couple beers my thoughts cleared and I realized the lens had/was slightly creeping away from infinity during the image capturing process which creates some interesting "features" during stacking. A few rubber bands and some tape cured the problem.

Anyway, this is a work in process and hopefully a beginning to a good start for a vertical setup.

Best,

Mike