RCA CD4012   Leave a comment

We decapsulated a RCA CD4012, a dual 4-inout NAND gate logic IC. The date code was unclear, but this was likely fabricated prior to 1970- near the dawn of the silicon age. We modified the decapsulation process to reduce damage, but the top SiO2 layer still shows signs of cracking and delamination from the sulfuric and nitric acids used. The four images were taken with oblique reflected, epi-brightfield, epi-DIC, and epi-darkfield illuminatiopn:

DSC05843 DSC05845
DSC05847 DSC05851

The schematic diagram, taken from the datasheet, is here:

Presentation1

The bonded wire lead located at 3 o’clock corresponds to pin 7. Even though this is a very simple circuit, I am unable to correlate the images with the schematic very well.

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