Improving heat transfer of ICs

[TheLaw117]

This thread belongs in the NerdAudio forums, not the DIYAudio Forums. Just Kidding

BTW, I REALLY LIKE the above post with the heatpipes on the chipamp!

Here's something simple I came up with (not built yet) that costs nothing, straight DIY.

IC Chip on Big Copper or Copper/Aluminum Hybrid CPU Heatsink (or heatpipe sink)
Coat the PCB, and chip leads with Waterproof Silicone Gel so water won't short it out.
Put Heatsink in Water Using a large plastic kitchen dish, tupperware, etc
Blow cooling fan on water surface.
Add water as it evaporates.

Simple, cheap, and keeps chip cool.

Use mineral oil. It's not conductive, and effectively does the same thing.

 

[TheLaw117]

Those heatpipes are certainly interesting, I'd love to see finished cabinets. It's got to be lighter than an equivalent solid sink. I imagine in some cases it could be better at cooling the device's immediate area than is theoretically possible with a solid snk?

Yeah I'm still working on it. It's been a couple months in the making. Finally figured out a plausible way to mount these buggers. That's one thing I didn't think about when I bought them...

They're going in a wooden enclosure, though that may be irrelevant to the conversation. They really do like nice. I haven't officially tested their cooling performance, but I should be done with everything by the end of the month, and I can let everyone know.

 

[digits]

There are two aspects to a heatsink, one is the thermal mass the other is the surface area. Alarge thermal mass will not have quick up and down swings in temperature, which leads to its own noise/distortion. I.e one transient isn't influenced by the thermal response to the transient just before it. Rather the system will gradualy increase or decrease its temperature A thick heatsink will draw heat away further and more efficiently than a thin one. Hold a piece of tinfoil in your hand and put a lighter under it some distance from your finger, the heat hardly gets to your hand, now do the same with a slightly thicker steel plate and feel the burn. The fool would say the foil was cooler, but thats only because all the heat stayed right on the point of the flame almost.

 

[marce]

Heatpipes are realy cool (!) and can get into awkward places to remove the heat, you can also get ribbon heat pipes.
TheLaw117, your chip amps with the pipes do look cool, active heat removal allows for more design freedom and more effective heat removal. It could lead to some pretty funky designs.

 

[tomchr]

you can dissolve the plastic package in acetone, or nitric acid

Acetone won't cut it. Many flux cleaners are acetone based so the chip packages are designed to tolerate it. Warm nitric acid on the other hand would work...

One could also just request the bare IC die from National directly. Wirebonding is not that hard... But given the amount of research, thermal characterization, and reliability testing that goes into semiconductor packaging designs I must say that the original poster must be on some sort of crack to believe he'd be able to improve on it. Unless he's some sort of mad materials scientist who really knows his stuff and has access to unlimited quantities of unobtanium. But if that was the case, he'd probably be developing the next generation IC packages and not asking questions here...

That said, I enjoyed the pictures of the chip amps with heat pipes. Nifty...

~Tom