Silicon under the Versamet

So I wanted to offer an update on the Versamet 2 and the lens adapter. It works!
I even managed to take some shots with it before I loaned it out to a friend of mine with a Canon 7D who really wanted to do some digital microscopy.
I was having some issues with the communications contacts for the EF lens mount on the camera. Modern DSLR cameras actually communicate with electronics in the lenses in order to operate some of their features like Image Stabilization, aperture and focus. My metal adapter ring actually shorted some of the contacts making the camera error out. A little bit of sticky tape solved the problem.
The images were also suffering pretty badly from a falloff in light as you left the center of the image. I didn’t have enough time to track down the problem and the best solution I had was to crop out 3/4 of each shot.

But one of the neat shots that I took in a failed photomosaic was this. This is one of the pieces of silicon from a module that was given to me by a gentleman I met and struck up an engineering conversation with. It’s a failed copy of one of the chips that went onto the Cassini spacecraft that is currently orbiting Saturn.

Wire bonds and some alignment marks
I don’t understand enough about Silicon to give a truly accurate description. But this chip specifically has large feature sizes for even a 1994 vintage. It’s a feature called VLI. As I was informed by one of the gentlemen who helped design this chip, the feature size prevents high energy particles from switching transistor gates and possibly creating a latch up failure.

Think of a bowling ball launched at the door of your house. The ball will likely blow your door right in or cause enough damage that it’s essentially open now. Now imagine that same ball crashing into a 50 foot tall blast door. It may do some damage, but you can’t arguably claim that the door is now open.
It might be a brute force tactic, but it works pretty well.


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