Comparing Two Heatsinks In A Commodore 64 (DF Robot vs. Easycargo)

A comparison of the performance of two common heatsinks. One of the two brands provided almost no decrease in temperature. The heat sinks were installed on the MOS 6526 CIA (U1) chip. A thermocouple was attached to the bottom of the chip to measure temperature. I included an overview of a way to improve such experiments in the future.

[@6581punk]

One of the things one of the Commodore engineers said (Might have been Bil Herd) was MOS chips often didn't have a very good resin casing, it would let in the air and cause oxidisation. Which makes me wonder if somehow sealing the chips somehow would help extend their life too. I imagine the chips running cooler helps stop this problem with the casing? Also, it was no surprise to see the heatsink with the least surface area was the worst performer. The more surface area the better when you use a heatsink.

[@joefish6091]

Industrial PCBs for potentially harsh environments get acrylic conformal coatings.

[@pickoftheglitter]

actually I'm not sure if sealing 40 yo chips today would be any good. About the surface area, usually the sides of the IC don't run very hot, since the chip itself stands in the middle. Of course, since the price of this heatsink is just cents, why not to put along the whole surface... but the hotter one will be always the one in the middle. When I open one of my Commodore computers (VIC, 64, etc.) I use to put heatsink in all the big ICs and as rule of thumb, when I open an old computer I observe what is the temperature of every chip; it runs hot, it gets an heatsink. In the C=64 I use more I also installed a little fan to blow air onto the VIC-II. It's a 12 volts fan with a resistor; it runs slower because of the resistor, so it's quite silent, but it's enough to keep the VIC-II totally cold (afaik it's the hottest chip in the C64).

[@stevesteve8098]

it's a double edged sword, actually it is maintaining consistent temperature. during that era , the dynamics of surface separation were not well understood.

[@tymscar]

I wish you would've shown us the aluminium heatsink with arctic mx4 too.

[@robertgaines-tulsa]

I figured the aluminum heatsink would win. It's all about surface area, and those fins provide it. More surface area to both radiate the heat and make so much more contact with the air to convect the heat away.

[@Kalvinjj]

Also being black only helps it. At least if the coating is done properly of course, too thick and it will become an insulator instead of helping with radiation.

[@Zarcondeegrissom]

yeah, the penny copper things are sad compared to ones I've seen eons ago that had much taller fins and less thermal mass in the base. I think it was around 20 years ago they stopped making good motherboard VRM heatsinks when motherboards started having fashion accessories over the VRMs. it's a bit sad as them blocks are a good size for cooling TO-220/TO-263 ICs. BTW, the copper is only good for looks, the tape and air contact area make the metal used a bit moot for small low watt devices, lol.

[@joefish6091]

You still need airflow and heat air exchange, otherwise the internal airspace of a piece of equipment just gets to X number degrees above ambient depending how well the enclosure exchanges heat with the ambient air. A small fan pushing air into the computer will dramatically lower the internal temps.

[@stevesteve8098]

NOPE!!!! it is about getting the heact out of the chip... and you can have the biggest assed heat-sink in the world and it will not make the slightest difference, if you are at the transfer rate of the interface material. Which is usually the resin and you can find that data on the chip specsheet. the heat goes from the silicon to the resin & leadframe. , and THIS is why socketed chips are a BAD idea., you are actually increasing the internal temp of the silicon die. , but you will get some smart ass who will measure the case temp and say nope!!! but they forget that the temp they are measuring is the resin case, which has a maximum thermal interface temp., it's NOT a perfect heat transfer system. if you look at the chip ends.. usually you will see 2 dots of metal at each end (old style chips), this is the lead frame the silicon sits on. the pins sit inside the resin & are connected by the bond wires. they remove the lead frame carrier on most modern chops.

[@DeadCat-42]

Let's use a nice bit of insulated foam tape to secure this heatsink......

[@dafoex]

I mean, it's maybe an easy mistake to make if it's a "high temperature" tape?

[@user-lz2mu9uq4e]

For high power chips it is common to have heatsink soldered to the ground pins. Plastic cases have too much thermal resistance.

[@joefish6091]

Fans, ie air pumps and openings.

[@jnharton]

Honestly the packaging on these chips is insulative, meaning that there's only so much a heatsink can do. It would be better if a way could be found to reduce the heat producedcin the first place.

[@simontay4851]

Undervolt them slightly. Say -0.15V

[@joefish6091]

Hence why audio amplifier ICs have ground pins tabs coming out the side, or flush (to PCB) HS plates under them. See the TPA3110 TSSOP package.

[@joefish6091]

@@simontay4851 TTL runs between 4.5V and 5.5V, ie rated at +/- 10% Replacing some TTL logic with 74HCL might be an option if the timings are not different and critical. Replacing any 78 or 79 series regulators with small SMPS types would removes some of the internal heat.

[@DrJ3RK8]

Those really should be combined into one product. The black one has way more surface area. The copper one conducts better without the coating. Then some kind of GOOD thermal tape could be used, and you'd probably see even better results. :)

[@ellisgl]

A bit of Dremel work to make the grooves deeper would probably help a bit.

[@joefish6091]

The flat HS is merely named as such, its junk. better tape will make no effective difference, the HS just sits there at the ICs temp and cannot radiate, a very high speed air nozzle etc etc, but the noise and the air pipes lol.

[@luisderivas6005]

The typical heat sink design in C64's was utilize the Faraday shielding as a heatsink, cutting tabs which would spring against the DIP IC's. A better option would be to use copper heat piping circuitously over each IC, out the case and attach pressed aluminum fins to the piping. Then attach a fan to blow through the fins. Copper transfer the heat well from the chips and aluminum does well at dissipating it into the air. Use thermal paste at the junctions or silicone embedded thermal transfer pads; no foam or tape.

[@kasuraga]

The platinum resistance temp sensor reminded me that's the exact same concept used to do temperature control for vapes, typically using titanium.

[@daijoubu4529]

Most thermal tape are just tape that resist heat, doesn't necessery mean they transfer heat lol, you'll want as much surface area for a fanless/convection heatsink thats why the copper one didn't do much

[@erintyres3609]

The 14 by 14 footprint of the aluminum heat sink is 1.25 times the area of the 12 by 13 copper heat sink. Its greater height is also beneficial. You did well to measure the back of the chip. Other reviewers would have just viewed the board from above with an infrared camera, but your method is much better. It is well known that copper conducts heat better than aluminum, but that alone does not make it a winner.

[@stevesteve8098]

ER there is a way, to predict the lifetime of chips It is a well known system used in electronics... That's where 50,000MBTF comes from ,and understanding manufacturing QA systems will give you the answers you require. and temperature plays a MASSIVE part in that, in fact that's how you do accelerated testing.

[@therealforge]

Good news: dfrobot used tape that will keep the heatsink attached to 4000F. Bad news: dfrobot used a tape that will help you reach 4000F.

[@SeanBZA]

I have had good success using metal loaded epoxy to bond heatsinks to hot running plastic DIP IC's, and also have used it to attach heat spreaders to 286 processors, which otherwise run smoking hot when run at high speed. I use larger heatsink units, extending a little past the edges, and after sanding the base of the heatsink flat using some 800 grit wet and dry paper on a flat surface, and the same to the top of the IC, then use some solvent to degrease the surfaces. Then a small amount of the epoxy, about match head size, in the middle, and press the 2 together firmly, till it is visible on the sides. Keep pressure on till gel time, so a 5 minute epoxy is best, then leave for 24 hours to cure before handling. Good bond, and about as good as thermal epoxy as well, with the temperature now being a lot lower with this new heat spreader. No need to buy exotic units, I have used common aluminium T shape extrusions along with other aluminium extrusions, originally intended as partitioning, which just were offcuts, and then cut to fit, and smoothed off, so you have a fin and a flat surface. Then prep the one flat surface to use it.

[@samuel_towle]

Depending how "deep in the weeds" you want to get... When dealing with heat surface area is number one. Watts/Square Meter Although copper conducts heat better than aluminum, the surface area difference of the aluminum overcomes that. Ambient temperature of the air (fluid) around the heatsink will also determine efficiency. The warmer the ambient fluid the less heat transfer. At a point where ambient becomes greater than the chip then the process will reverse. Hence the CPU fan / water pump to replace the warm ambient fluid with cool Each material between the die and the ambient air will have some effect on heat transfer. Some are good, some are bad. The chip encapsulation material. the adhesive pads (if used) the heatsink material, the heatsink coating, down to the tiny air gaps between the chip surface and the heatsink surface which is why we use thermal compound to increase the surface contact area for transfer.

[@elmariachi5133]

Hey, nice experiment! I though about this somtimes, as these are the two most common cooling blocks you can cheaply get everywhere ..but never had enough patience for trying out xD But I'd recommend using thermal glue, like Silvberbead. I was expecting the 'long and thin' approach to fare better already .. if they only produced this shape from copper .. Also maybe we should start fitting fans into our C64 cases ..

[@cheater00]

bro that 5ps pan at the start gave me a migraine lmao

[@2OO_OK]

Can you add some forced airflow? These heatsinks are just stewing in the heated air around them. Also the copper heatsink may be aluminum with copper coating.

[@SianaGearz]

Nah this is for sure a real copper heatsink. You can tell just when you hold them that the density of metal is much higher. If it was any other metal it couldn't have possibly performed nearly this well. You expect to achieve approximately as good a performance in half the total volume envelope when using copper as opposed to aluminium, for ideally designed heatsinks, and in this regard, it comes remarkably close, being as tiny as it is and half as tall as the aluminium one plus a little smaller in footprint. Both heatsinks have some design compromises, the aluminium has its base and fins maybe a little too thin, while copper one has its base too thick and radiation area is too small.

[@2OO_OK]

@@SianaGearz The Air velocity and temperature are limiting performance here. If the "copper" heatsink were steel or zinc with copper plate you are unable to tell the difference by picking it up The dimensions of the "copper" heatsink make no sense for a material with such good thermal conductivity.

[@SianaGearz]

@@2OO_OK If it was a steel or zinc heatsink, it would not come anywhere near close to the performance that it has shown, it would fare much much worse. Don't expect magic from copper heatsinks just because it's copper. Of course it can be demonstrated that it's same material throughout and not just surface plated by cutting into it. I had cut into heatsink looking just like this a long long time ago and it was genuine, though of course it doesn't mean that new production is. But i also pay about 6 times more for copper heatsinks than for aluminium ones, they don't cost the same. I had as such not run into fake copper heatsinks yet, but it would indeed be easy to fake by plating, so buyer best beware.

[@MicraHakkinen]

Would undervolting be an option? I would imagine that also helping extend an IC's lifespan.

[@Bernard_Ashtree]

EST, Mtl: My guess is, for the copper one it's more useful with a fan

[@wernerviehhauser94]

"thermal tape" is meant to counter air gaps. It is, in itself, not a good thermal conductor (NO thermal contact material is. Not even silver filled Arctic younameit). But it conducts orders of magnitude better than air. As for the heatsink material, copper does not really improve things that much since it's higher thermal conductivity does not improve the heat transfer from the chip into the metal or the heat transfer from metal to air. Two geometrically identical heatsinks will make the copper one the winner, but not by much. I have seen themally conductive PLASTIC heat sinks perform on the level of aluminium for small power applications - and some of my LED bulbs use that. A piece of aluminium sheet might outperform the tested heat sink (that's what I have in some C64, the others use SOTS DIL heat sinks) since fins usually like to have forced convection.

[@maxhammick948]

The plastic insulation on power cords increases the heat transfer from them - critical radius of insulation for PVC is a bit under 1", so up to 1.5" diameter increasing the insulation thickness means they run cooler. Plastic is widely used to dissipate heat, despite being widely dismissed for that role. The fins on that sink should help a lot under natural convection, as the vertical surface is aligned with the flow of hot air. Aluminium sheet is a cheap way of buying heatsinks, until you run into the sinks for other components on the board!

[@wernerviehhauser94]

@@maxhammick948 interesting. I know that painted bus bars have higher current carrying capability than unpainted ones, but I never heard about that on wires. Got any data or referrence on that?

[@maxhammick948]

@@wernerviehhauser94 The extra surface area helps more than the added thermal resistance, because one increases linearly with radius and the other with ln(radius). It all boils down to r(crit) = thermal conductivity / convective heat transfer coefficient; youtube doesn't like links in comments but the derivation is widely available online if you google "critical radius of insulation"

[@maxhammick948]

@@wernerviehhauser94 KZbin seems to have eaten my first reply, so second attempt: - adding more thickness adds surface area faster than thermal resistance, for small diameters (and small depends on the thermal resistance of that material and the convective heat transfer coefficient) - for a full derivation, google "critical radius of insulation" - it's in many places online

[@maxhammick948]

​@@wernerviehhauser94KZbin keeps eating my comments, so hopefully this gets through. Below a certain size the extra surface area helps more than the extra thermal resistance - the derivation for critical radius of insulation is replicated in many places online if you want to see the maths

[@Knaeckebrotsaege]

Bold of you to assume the generic chinese junk heatsink (labeled DF robot here for some reason), is *actually* copper at that price point, cause it's not. It's colored aluminum (or some aluminum based alloy, read: metal mix that isn't pure and therefore even cheaper to produce). its weight should've been a clue. Add to that minimal surface area with those pitiful "fins", _and_ the tape that isn't actually thermally conductive at all (like you've mentioned, it's literally just doublesided tape), and you might as well leave them off

[@TwoBlackMarks]

Have you tried mounting a small fan in the chassis? Either pushing or sucking air out/in? And tested the temperature change? Is there some universal rule to how hot chips should get, or not go over? Is it possible for it to be too cold too?

[@simontay4851]

My rule is below 60C.

[@SianaGearz]

Every 10°C increase roughly doubles the speed of degradation. But there's no hard rule to how long they have to survive at a given temperature, many semiconductors last for 20 years continuous 80°C and more. Indeed if you can touch it bare hand and not feel being burned alive, so on the order of 55-60°C maximum, that is definitely well on the safe side. As long as you don't get condensation, run classic chips as cold as you can manage to. Deep cooling under the ambient temperature is potentially a little unwise for this reason, but there's no harm in adding airflow and indeed this will increase heatsink efficiency drastically.

[@TwoBlackMarks]

@@SianaGearz A cool project would be mount an effective fan that sucks, rework the chassis/body so it is sealed the right places, you can add heat sinks that you connect with the RF shield, you redo the RF shield in aluminium, no edges, just smoothly radiused bends where needed, add a correctly sized bellmouth where the air should get in. Oh, that would be a nice flowing cooling system. You could do a ligth version though, with only cooling where needed, but a custom Aluminium RF shield with louvers and fins would probably help if done correct.

[@joefish6091]

I just watched a video about the Intel 13th and 14th gen CPUs, seems they run at insane wattages and are failing massively.The newer monster GPUs are also prone to temp problems.

[@tarstarkusz]

0:28 While it may make sense to you, it is false. Many chips have failed from age alone. Item worked perfectly when put away, item is pulled out 40 years later and doesn't work.

[@nbrown5907]

From first glance the Easycargo should cool better because of more surface area to dissipate heat.

[@TheHoss4145]

You know there are extra heatsinks designed for (P)DIP Packages?

[@Retrommodore]

Yes. The DF Robot was meant for a Raspberry Pi. I ordered these because of the price and width matching the DIP IC being cooled. It wouldn't surprise me if I missed something better and cheaper. 😄

[@TheHoss4145]

@Retrommodore digitec sells a brand which are a dollar each and well worth it.

[@g4z-kb7ct]

Were the tests using just 1 heatsink? Needs 3 or 4 really. The older they get the hotter they get so nowadays the vics need a fan+heatsink, heatsink alone doesn't do enough. On one of my c64s I used a fan and heatsink taken off an old geforce mx2 junk video card and it runs super cool.

[@LordHonkInc]

You can see three of the copper heatsinks mounted on the VIC at 6:06 so I assume that's how they were tested, but I agree, these small heatsinks have too little thermal mass and too little surface area for what I'd consider long-term-solution temperatures. Still better than nothing, but yeah ¯\_(ツ)_/¯

[@Retrommodore]

One heat sink of each kind was used for the test. When it comes to VIC and VIC-II I put three on.

[@jtveg]

Thanks for sharing. 😉👌🏻

[@replikvltyoutube3727]

Not bad, what about overclocking?

[@dafoex]

Water cool your C64 because it'd be funny

[@fayabitster]

id be using my c64 if it worked but sadly it only showed a power light with no video and i dont have the time or money to actually fix it so i decided to take its guts out so i can put a hp laptop motherboard that i salvaged out of a broken laptop to make it a sleeper build (dont worry i didnt throw away the internals im saving them for the day i can actually fix it)

[@Hchris101]

Neeto

[@nihonjorge]

Copper is very good at taking the heat from the chip, but is terrible at releasing that heat into the air. Aluminum is the opposite. It's not so good at taking the heat from the source, but it's excellent at sending the heat into the air. Copper just gets really hot and takes ages to cool down. If you combine copper and aluminum, you get the best of the two worlds.

[@trippycat]

Wouldn’t two different metals touching cause a galvanic reaction which would lead to corrosion?

[@gwong940]

@@trippycat only if there's an electrolyte, which there should not be in this case.

[@trippycat]

@@gwong940 would a graphite thermal sheet further reduce the chance of galvanic corrosion due to humidity in the air?

[@dirtyclanner2250]

That's just wrong. Copper is great at conducting temperature, both heat and cold. It doesn't magically easily gets hotter and don't release the heat outside, otherwise we would have a perpetual motion machine based on this. Also, this is against laws of thermodynamics. The problem with the copper heatsink in the video is the surface area, it's multiple times smaller than that of the aluminum heatsink.

[@Kenshindegozaru]

​@@dirtyclanner2250 No idea if you are right or wrong, but I'm talking from experience. I tried a copper heatsink to cool a chip and it just gets really hot, really fast. You can put your hand close to it and not feel the heat in the air. Tried the same thing with an aluminum heatsink, even a little smaller than the copper one, and it stays at a lower temperature and you can feel the heat in the air. I also don't think it goes against thermodynamics. If you take more energy than what you lose or release, you get hotter until you meet equilibrium or it melts. Maybe I have some concept wrong.