X-ray Analysis of the Apollo Saturn V LVDC Circuit Board

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UPDATE Feb. 4, 2013: for final analysis and descriptions of the LVDC logic devices read my blog posting here:
My preliminary analysis of the Saturn LVDC board:
- The X-ray image is negative, so white elements are completely blocking the X-rays while black parts show no obstruction. Most of the board is grey due to the continuous ground plane and overlapping traces, and white spots mostly indicate lead solder.
- Each logic device package contains 4 semiconductors. The ceramic wafer bases of each logic package have conductive traces deposited on both the top and bottom sides, and the semiconductors (called Flat Chips) are surface mounted with solder balls by reflowing to these traces face down on the top side of the wafer (it has been noted that the later IBM 360 logic devices were made in this manner- see link below). The small white square shapes you see arranged in threes are the solder pads connecting each semiconductor to the traces.
- The board has a continuous ground plane layer, and the only openings are around the vias, which you can see as a black ring around all of the via pads that show a clearing through all layers.
- The logic packages do not appear to contain capacitors.
- This board has a lot of layers!
- The bone in my thumb is apparently not broken. :)
Full size images and updates available on my engineering page here:
More documentation online about the LVDC:
The IBM 360 devices: