Noctua NA-TPG1, the AMD AM5 CPU guard against thermal paste
The large number of creases on the heat spreader of CPUs for the AMD AM5 platform means a lot of places where thermal paste can run off and dry out. Removing it is then very laborious when cleaning, which is why Noctua has released a frame to protect these critical spots. And it will also protect the exposed SMD next to the heat spreader from paste or possibly liquid metals.
If there’s anything atypical about AMD Ryzen 7000 processors, it’s the shape of their heat spreader. Instead of a square (or rectangular) base, it’s a sort of strange polygon. This was created by “receding” from small capacitors on the PCB surface. But that’s only somewhere, where it’s necessary (on the sides of the individual chiplets that are under the IHS). And since the heat spreader uses almost the whole free PCB surface, it resembles a kind of star shape. Although admittedly a bit more angular and with a fuller center.
The centre (contact area) is quite small, but after excluding the protrusions at the sides and corners, it is still square. However, it should be noted that it is significantly smaller even compared to processors for Intel LGA 1200/115x sockets. And estimating the optimal amount of thermal paste when using the droplet, but give for example also the cross method of application, is quite difficult. This is also taking into account that the chiplets with CPU cores are very close to the edges of the heat spreader (and thus it is advisable to get the paste onto these areas as well). In short, from a cooling point of view, it’s better to apply a little more paste here (but again, in moderation, of course) than less. But then the paste will naturally run down the walls of the heat spreader and also get into the rectangular corners, which are extremely difficult to clean.
For this reason, Noctua released a bezel that offsets the jagged IHS and fits it like a counterpart. This means that the thermal paste stays on it, thus this bezel also protects the outer SMD. You’re probably aware of how hard these parts are to clean (and how dangerous it can be for their fragile soldering), although that paste doesn’t hurt them all that much again. That is, as long as it is electrically non-conductive. In the case of a liquid metal encounter, the consequences could, naturally, already be diminishing. And because of the high temperatures, the occurrence of its application on Ryzen 7000s will probably not be rare.
However, the Noctua frame is also protective in this respect. Once it is mounted, the liquid metal just does not get on the SMD. By design, it is actually a kind of polycarbonate insert, i.e. made of a sufficiently strong material that will not warp even with such a small thickness. Polycarbonate is also used to make the shields of hockey helmets, for example.
The NA-TPG1, as Noctua refers to this guard, does not interfere with the cooler in any way, but neither does it lie on the SMD. It is supported at eight points by the protruding parts of the IHS feet, with a 1.5-millimeter spacing from the PCB. You can’t buy the Noctua guard separately, but it will be available as part of various kits. With three NA-CW1 wipes with alcohol-based solution (NA-STPG1) for a recommended price of 7,90 EUR or with 3,5g thermal pastes NT-H1 (for 9,90 EUR) and NT-H2 (for 13,90 EUR) in the AM5 edition.
