In (rec.radio.amateur.homebrew), Keith wrote:

Unfortunately, boiling the CFC also distilled it, leaving any
contamination on the chips. The result came to be known as the "black
plague". Because of the "black plague" the "LEM" (Liquid Encapsulated
Module) was replaced by a similar looking (though shorter) "TCM" (Thermal
Conduction Module) which used pistons on the backside of the chips
(increased to 121 chips) to transfer heat (10W per chip, 1200W total) to
the cold-plate and filled with helium. The TCMs were used throught the
'80s and early '90s for the high-end ECL systems.

Yep. I've got a TCM somewhere at home; I need to take a pic of it
for my web page. IIRC, it has 1024 pins, and the largest ZIF socket
I've ever seen. The cold plate on the TCM is about 4.5" square, very
smooth, and designed to go on a larger water-cooled manifold with some
dozens more TCMs, all getting water from a chiller.

They're called "wet-frame" machines by a lot of us who dealt with
them, and especially by those of us who had a leak develop somewhere
in the cooling system.

Nowadays one TCM's circuitry fits on a single chip, at a meager
fraction of the TCM's dissipation, and is enormously faster, so that
(for 9672 hardware, anyway) IBM ships the machine with a bunch of CPUs
and licenses you the code to turn on as many as you're paying for. If
you want more than ship in the base machine, they'll install another
dozen pretty cheap.

And the homebrew and design connections:

They're sure not homebrew, and they're more than one designer can do.

--
Mike Andrews

Tired old sysadmin