Dtl, 1 month ago

The IC is in the CT system.

Dtl, 1 month ago

First projection.

Dtl, 1 month ago

Volumetric render of the CT scan, showing the leadframe, bolt, what looks like a separate slug of metal and the die.

Cross section of IC showing a grey rectangle (the plastic package) with a hex pattern in the plastic, there is a metal circle with a square cutout for the die
Cross section of IC looking down the length between the pins. There is a void above the IC die, with a glued on lid above it. The pins point upwards. You can see the bolt, the metal slug or metal paste and the indent where the die sits.
A different cross section showing the IC with the void, the lid and the bolt.

ModelMakerVille, 1 month ago

@Dtl @philpem

I think I may have been for an interview at Plessey back in the day.
Them and Ferranti.

philpem, 1 month ago

@ModelMakerVille @Dtl They made some interesting kit, their later chips went all the way into the realms of DMAC/D2MAC decoding and RF PLL synthesisers, then early ARM microprocessors. Very cool stuff.

azonenberg, 1 month ago

@Dtl @philpem That's only the second chip I've seen with a heatsink mounting stud attached to it (the other being a giant DEC chip from a VAX with twin gold plated studs).

growlph, 1 month ago

@Dtl @philpem Wait this is real? o.O

philpem, 1 month ago

@growlph @Dtl Oh yes. This cursed thing is a real thing, which back in the 70s, Plessey would happily sell you.

penguin42, 1 month ago

@philpem @growlph @Dtl I like the fact it's just a plain hardware-store bolt; The Alpha cpu's had threaded attachments for the heatsink (and the manual told you torque settings) but at least they were moulded into the heatspreader: https://www.chipdb.org/img-dec-alpha-21164-p6-433-21-43918-42-5841.htm

bread80, 1 month ago

@Dtl @philpem As used by Dr Frankenstein in the audio output circuits of his monster. Thus explaining the large nuts on the side of its neck.

haifisch, 1 month ago

@Dtl @philpem @gsuberland wowow I’ve never seen anything like this, am very curious how these were manufactured… imagining someone manually plopping in a bolt into wet epoxy, directly on top of the die? Lookin forward to the X-ray breakdown!

RavenLuni, 1 month ago

@Dtl @philpem heat sink?

philpem, 1 month ago

@RavenLuni @Dtl yeah, it's a high-ish-power audio amplifier. The bolt was to make it easier to fit to a heatsink, and improve heat dissipation.

philpem, 1 month ago

@Dtl Oh wow, you got one? I was just pooptooting about it, but I'd be very interested to see the X-rays!

gsuberland, 1 month ago

@Dtl @philpem delightfully cursed