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I noticed a lot (but not all) of ceramic packages seem to have a gold line.

What is the function of this line? (I'm not talking about the soldered cap that the die will be placed under, but the gold line going towards the bottom-left of the package in the picture below).

Enter image description here

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    \$\begingroup\$ I asked the same question over on retrocomputing.se. It's a grounding line for the metal cap over the die. \$\endgroup\$ Oct 18 at 20:38
  • \$\begingroup\$ Perhaps the cover was attached using e-beam welding which requires a ground connection. \$\endgroup\$
    – qrk
    Oct 19 at 0:59
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That's often (but not in this case) connected to ground. You can see that the connection has been cut at the end of the package.

In some cases the chip is designed to have the cavity, to which the substrate of the chip itself is bonded, grounded or sometimes connected to some other voltage reference and this is how it's sometimes done.

By grinding away at the end, as is the case with this example, the connection is broken and the lid is not connected to anything.

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    \$\begingroup\$ But these chips are 30 to 50 years old. I have some that the epoxy has crystallized and turned to dust to leave the gold ribbon unattached (barely attached) to the ceramic. Someone may have scratched off the lose ribbon over the years. There is a reason it has not been used. Or it may be present and a photographic lighting issue. \$\endgroup\$ Oct 18 at 20:03
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    \$\begingroup\$ What epoxy? There is likely no epoxy in this style of package. It's ceramic and gold. \$\endgroup\$
    – jwh20
    Oct 18 at 20:05
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I believe that gold trace connected the cap to ground to create a grounded plane above the die.

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Multi-panels techniques are very often used in almost all the industrial manufacturing phases.
In this case, I think the track is just used in order to connect together all the large pads on the top ceramic (over which the single cap is then soldered) in a multi-panel arrangement.

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