In thermal management there is a simple principle... moving heat.
First up is the heatsink itself. The heatsink is a rather common design and includes an oil filled pure copper heat pipe permanently mounted to an aluminum and fill metal attachment grid that is mounted under spring tension coupled to both the cpu and gpu with thermal paste and/or a silicone thermal pad. Usually a thermal pad for the gpu and thermal paste for the cpu. The heat dissipation matrix is comprised of an aluminum hollow core box type radiator that the fan blows through to remove the heat from the assembly.
Lets get a basic understanding: Copper has a higher thermal conductivity, and therefore is superior to aluminum in processor cooling. Copper is better at conducting heat than aluminum, but aluminum is able to radiate the heat into the air better than copper because of its lower density
Lets take a look at the numbers:
Thermal Conductivity: λ / W·m−1·K−1 (Pure Metal)
But we must remember densities:
Now let us think of the "skin effect" of a 3-6 um coat of copper atop the aluminum substrate to allow the heat to transfer through the fins and "amass" at the very edge to be removed by the incoming cold air blown through the fins by the fan. In short, a tiny layer of copper would increase the heat dissipation.... this leaves a conundrum because it is difficult to plate aluminum with copper due to a number of reasons. The usual process is to first plate it with Nickel, and then plate copper atop that harder Nickel surface, however in this instance the Nickel would reduce the "skin effect" and heat transfer that we are looking for.
Method: There are multiple methods of electroplating, but taking the aforementioned factors into account the option was quite clear: A novel and highly effective electroplating method that utilizes peracetic acid to slowly electroplate a pure copper "skin" utilizing the distance between anode and cathode to slow the plating process to facilitate strong bond between the aluminum substrate and the deposited (electroplated) copper.
First, Source a PURE COPPER scrubbing brush; Make absolutely sure that it is not a copper plated metal brush but truly a PURE, SOLID COPPER "brillo" style pad... you can use other forms of copper, but the hassle of reducing them to a surface area that will be useable for electroplating is not worth it. -(I recommend ebay) **Remember**- Any contamination with another metal will effect the outcome negatively... even the short time the metal to be plated comes in contact with the solution before plating occurs can poison the results.
Secondly, source white distilled vinegar and standard 3% H2O2 (Hydrogen Peroxide) -(I recommend Wal-Mart or equivalent)
Thirdly, source a large enough container made of plastic, nalgene, or glass (preferably with a top to protect the remaining solution for reuse)
Fourthly, You'll need a 6 volt battery and wires with alligator clips for your anode and cathode.
And Obviously - your heatsink (or other item to be electroplated)
Common sense applies.. here are the important details:
First carefully remove the heatsink and clean with soap and water fully before cleaning every inch with IPA (Isopropyl Alcohol) **70% or higher is best. Pay close attention to the area that contacted the gpu and cpu to remove any trace of oil, adhesive, or thermal compound which is generally a mixture with a silicone oil or mineral oil base depending on the brand / type... even silicone pads are impregnated with silicone oil to aid in contact transfer so clean this area perfectly WITHOUT scratching the surface that will make contact with CPU / GPU... the cleaner the interface, the better the thermal transfer.
Now we make our Metal Ion Electrolyte Solution - In this case for electroplating copper onto such a difficult substrate as aluminum we will be utilizing peracetic acid as our electrolyte.
Take your container, your vinegar and H2O2 (hydrogen peroxide) and prepare your initial peracetic acid solution by mixing equal parts of distilled white vinegar (~8% acetic acid solution) and Hydrogen Peroxide (~3% H2O2 solution) which will yield peracetic acid in short order.. I will not bore you with the molar equations, but it is important to note that you should be careful with this solution... even dilute peracetic acid is a potent antimicrobial and commercial sterilizer that will also eat copper for dinner... You should know that in a pinch with proper handling and safety this solution by itself makes lysol look like an agar solution to nasty germs and bacteria.
At this point you should take a pinch of your pure copper scrub brush and roll it into (2) 3" by 1/2" tubes and attach them to your wires (preferably with alligator clips) and attach the other side of the wires to your 6 volt battery... Now dip the two copper rolls into your solution about 2" apart and watch the magic happen as the copper ions leach into the solution turning it a blue color... you want to the solution to be a light blue color at the start of the plating process so stir the solution with one of the copper pieces until the entire solution is a light sky blue color.... At this point you want to remove the copper sponge (or what is left of it) from the negative wire alligator clip and attach it to your heatsink to be plated... we don't want any hotspots or flaking so keeping the item to be plated at least 2 inches from the copper anode, gently dip the heatsink into the solution and swirl it around until an initial plating is achieved... continue this procedure until the entire item is appropriately copper plated at a thickness of ~2-4um thickness.... an even copper shine... you will want to constantly move the item to be plated and move the side facing the anode from back to front often to achieve an even plate with no hotspots. It takes some practice, but if you follow these instructions you should be a pro in no time. The slower the plating process the better so increasing the distance between the item and the anode will slow the plating process as the resistance increases in the solution... If the solution becomes too dark a blue color meaning that it is loaded with an ecess of copper ions you can decant a bit of the solution and add a bit more electrolyte or just add a bit of H2O2 as it is better to have a slight excess of H2O2 rather than an excess of Acetic acid... immediately after you complete the process wash the item in cold water (preferably distilled deionized water, but distilled water will suffice) and lay the item on a paper towel to dry.
after it has dried and you polish the surfaces of the heatsink that attach to the CPU and GPU with a microfiber cloth you will be ready to reinstall it with new and preferably better thermal paste.
This simple mod will lower your CPU and GPU temps significantly and will last for the lifetime of the machine. (Combining this with ThrottleStop software will greatly enhance your control over thermal management.
**Notes: I have been extremely unhappy with available thermal pastes and silicone pads (including the arctic silver and liquid metal paste as well as many others) so I made my own Utilizing a Proprietary Blend using a specialty base and nano Silver, Nano Diamond (Natural Diamond) and Nano Hexagonal Boron Nitride, etc. by running them through my Purpose Purchased Retsch ZM100 Centrifugal Grinder before finishing in a Spex Shaker to achieve .5um and lower powder particle sizes and Homogonizing with a milkshake mixer and a Retsch Grindomix GM200 knife mill and packaging the resultant mix (which has a higher W/mK transfer effect and better stability than anything I've found) in syringe dispensers... But that's a project story for another day... I test marketed them on ebay for a while and am thinking about marketing them commercially for like minded individuals that like quality along with a pricetag...