A few months back, I was watching TechTV, and a segment on immersing a motherboard in a cooling bath was showing. They used a solution called hydrofluoroether from 3M. It's non-volatile, is safe on all materials, and will last forver if not boiled. They cooled the fluid with an aquarium pump and an ice bath, but it gives up heat readily without it. Might be worth a try.
http://www.techtv.com/screensavers/supergeek/story/0,24330,3340252,00.html
http://www.techtv.com/screensavers/supergeek/story/0,24330,3340252,00.html
that Fluorinert seems like just the ticket for Peter.
He could put the gainclone "bug" in the bottom of a 2" vertical copper pipe. Then would a heatsink (copper fins soldered on?)at the top of the pipe make it into a heatpipe? Maybe if the tube is about a foot tall he doesn't need a heat sink? I guess it depends on whether it goes through a phase change and at what temp? right?
at the least, he should be able to get more power from the chip, but that doesn't seem to be the way to best sound. Who knows, maybe well cooled, a high output gainclone would sound great!!!
He could put the gainclone "bug" in the bottom of a 2" vertical copper pipe. Then would a heatsink (copper fins soldered on?)at the top of the pipe make it into a heatpipe? Maybe if the tube is about a foot tall he doesn't need a heat sink? I guess it depends on whether it goes through a phase change and at what temp? right?
at the least, he should be able to get more power from the chip, but that doesn't seem to be the way to best sound. Who knows, maybe well cooled, a high output gainclone would sound great!!!
Hi,
before you want to damp the chip, you must know what you are trying to achieve. My experience is that chips can act as strain gages. (Strain gage is a device for measurements of micro deformations. It is basically a resistor bridge glued to a surface whose deformation you want to measure. When surface deforms, bridge leg changes resistance and imbalances bridge. You then amplify resulting voltage difference and measure deformation).
As an engieneer i did not beleive in such a crap as chips are sensitive to vibration until i got 200mV offset from SO8 LF157 opamp just by bending the PCB it was mounted on. And that was consistent across 4 chips that were soldered on that PCB. At first i thought that it must be SMD resistors changing resistance as in strain gage, but after desoldering resistors and connecting them with 0.1mm magnet wire results were the same. I had to redesign the circuit with DIP8 versions.
So the idea is how to introduce minimum stress to the silicon chip itself. Since chip is soldered to the copper tab, you may want to stress the tab as little as possible. In my opinion the best way would be to attach chip to as thick and stiff piece of copper as possible. You could solder it to block or you may use clamp to press chip against the heatsink. I would avoid screwing chip to the heatsink, since this deforms the tab.
Another point which seems to be missed here is transfer of vibration through component leads. By use of point to point wiring you seem to put a lot of strain to the leads and then through epoxy encapsulation to the chip itself. So idea would be to use small pieces of thin flexible wire between chip and the rest of the components. Do not worry about the length of the interconnetcs, it is not the length but the loop area which is important. By twisting thin wires together you would achieve much less loop area anyway.
Best regards, Jaka Racman
P.S. Avoid deionized water as hell. This is one of the most corrosive liquids i have ever seen. Only metals than can resist it are titanium and to a lesser degree special grade of inox whose surface must be specially chemically treated. It can even dissolve certain ceramics.
before you want to damp the chip, you must know what you are trying to achieve. My experience is that chips can act as strain gages. (Strain gage is a device for measurements of micro deformations. It is basically a resistor bridge glued to a surface whose deformation you want to measure. When surface deforms, bridge leg changes resistance and imbalances bridge. You then amplify resulting voltage difference and measure deformation).
As an engieneer i did not beleive in such a crap as chips are sensitive to vibration until i got 200mV offset from SO8 LF157 opamp just by bending the PCB it was mounted on. And that was consistent across 4 chips that were soldered on that PCB. At first i thought that it must be SMD resistors changing resistance as in strain gage, but after desoldering resistors and connecting them with 0.1mm magnet wire results were the same. I had to redesign the circuit with DIP8 versions.
So the idea is how to introduce minimum stress to the silicon chip itself. Since chip is soldered to the copper tab, you may want to stress the tab as little as possible. In my opinion the best way would be to attach chip to as thick and stiff piece of copper as possible. You could solder it to block or you may use clamp to press chip against the heatsink. I would avoid screwing chip to the heatsink, since this deforms the tab.
Another point which seems to be missed here is transfer of vibration through component leads. By use of point to point wiring you seem to put a lot of strain to the leads and then through epoxy encapsulation to the chip itself. So idea would be to use small pieces of thin flexible wire between chip and the rest of the components. Do not worry about the length of the interconnetcs, it is not the length but the loop area which is important. By twisting thin wires together you would achieve much less loop area anyway.
Best regards, Jaka Racman
P.S. Avoid deionized water as hell. This is one of the most corrosive liquids i have ever seen. Only metals than can resist it are titanium and to a lesser degree special grade of inox whose surface must be specially chemically treated. It can even dissolve certain ceramics.
I made an oil cooled amp.. sortof... its the basic circuit from the LM3886 data sheet... without the filter caps near the chip... (4 resistors, a capacitor, and the chip) all are mounted over the chip.... I am using CAT 5 cable to apply power, and feed the signal into the chip.. as well as get the speaker output from it. 
so... I have a piece of metre long CAT 5 solid core cable, connected to a little black box with a few resistors and a capacitor.... connected to the end of this piece of cable is a powersupply (consisting of a transformer, bridge, and 10,000uF per rail) there is a speaker terminal.... and a audio input socket.. (sorry no pictures) the chip, capacitor, and resistors are all submerged in a jar of oil (cooking oil) this oil is then stirred with a magnetic stirrer..
so... I have a piece of metre long CAT 5 solid core cable, connected to a little black box with a few resistors and a capacitor.... connected to the end of this piece of cable is a powersupply (consisting of a transformer, bridge, and 10,000uF per rail) there is a speaker terminal.... and a audio input socket.. (sorry no pictures) the chip, capacitor, and resistors are all submerged in a jar of oil (cooking oil) this oil is then stirred with a magnetic stirrer.. "the chip, capacitor, and resistors are all submerged in a jar of oil (cooking oil) this oil is then stirred with a magnetic stirrer.. "
Just a thought - you could turn the volume way up to heat the oil, throw in a few fries or onion rings, and bop to the tunes while cooking your lunch. Maybe even invite a few friends over for some dancing and fondue.
Just a thought - you could turn the volume way up to heat the oil, throw in a few fries or onion rings, and bop to the tunes while cooking your lunch. Maybe even invite a few friends over for some dancing and fondue.
Why not doing something more radica...
Sometimes we play around with liquid Nitrogen here at work. That should be sufficient to cool just about anything (except for the stuff we use liquid Argon or Helium to cool)... ;=)
For this you just clamp the chip to a small heatsink, turning it upside down with the fins downwards and dip it into the fluid.
Simple... But it is quite hard to get the Nitrogen on the public market, though.
//magnus
Sometimes we play around with liquid Nitrogen here at work. That should be sufficient to cool just about anything (except for the stuff we use liquid Argon or Helium to cool)... ;=)
For this you just clamp the chip to a small heatsink, turning it upside down with the fins downwards and dip it into the fluid.
Simple... But it is quite hard to get the Nitrogen on the public market, though.
//magnus
I don't think I'd trust immersion in a liquid to cool any higher powered ICs. Seems like it would be better to torque the puppy down to a slab of aluminum or copper.
Water definitely wouldn't work. Oil would be a more viable alternative, if such an alternative even exists.
On another note, I know that old submerged motors and such were filled with peanut oil.
Water definitely wouldn't work. Oil would be a more viable alternative, if such an alternative even exists.
On another note, I know that old submerged motors and such were filled with peanut oil.
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