AMD Ryzen 7000 CPU Delidding Reveals Gold-Plated IHS & Zen 4 CCDs With High-Quality TIM
The CPU that was delidded is part of the Ryzen 9 family since it has two dies and we know that the two CCD configuration is only applicable to the Ryzen 9 7950X & the Ryzen 9 7900X. The chip has a total of three dies, two of which are the aforementioned AMD Zen 4 CCDs fabricated on the 5nm process node and then we have the larger die around the center which is the IOD and that is based on a 6nm process node. The AMD Ryzen 7000 CCD measures at a die size of 70mm2 compared to 83mm2 for Zen 3 and feature a total of 6.57 Billion transistors, a 58% increase over the Zen 3 CCD with 4.15 Billion transistors.
Scattered around the package are several SMD's (capacitors/resistors) that usually sit under the package substrate if we consider Intel's CPUs. AMD is instead featuring them on the top layer and as such, they had to design a new kind of IHS which is internally referred to as the Octopus. We've already seen the delidded IHS before but now we get to see a final production chip with no lid on it to cover those gold Zen 4 nuggets!
With that said, the IHS is an interesting component of the AMD Ryzen 7000 Desktop CPUs. The one picture shows the arrangement of the 8 arms which Robert Hallock 'Director of Technical Marketing at AMD' refers to as the 'Octopus'. Each arm has a small application of TIM beneath it which is used to solder the IHS to the interposer. Now delidding the chip is going to be really hard since each arm is right next to the massive array of capacitors. Each Arm is also slightly raised to make room for the SMDs and users shouldn't worry about heat getting trapped beneath.
AMD Ryzen 7000 Desktop CPU Delidded (Image Credits: GamersNexus):
1 / 4
Der8auer has also given a statement to Gamers Nexus regarding his upcoming delidding kit for AMD Ryzen 7000 Desktop CPUs which is in the works and he also seems to explain why the new CPUs feature gold-plated CCDs:
Regarding the gold coating, there's the aspect that you can solder indium to gold without the need of flux. This makes the process easier and you don't need aggressive chemicals on your CPU. Without the gold coating, it would theoretically also work to solder the silicon to copper, but it would be more difficult and you would need the flux to break the oxide layers.
Der8auer to GamersNexus
The most interesting area of the AMD Ryzen 7000 Desktop CPU IHS, besides the arms, is the gold plated IHS which is used to increase thermal dissipation off of the CPU/IO dies and directly to the IHS. The two 5nm Zen 4 CCD's and singular 6nm IO die have liquid-metal TIM or Thermal interface material for better heat conductivity and the aforementioned gold plating does help a lot with heat dissipation. What remains to be seen is whether the capacitors will feature silicone coating or not but from the previous package shot, it kind of looks like they do.
RELATED STORYHassan Mujtaba
AMD’s 5nm Dragon Range “Zen 4” High-Performance Mobility CPUs Would Offer A Monumental Performance & Efficiency Leap Over Zen 3
It is also reported that the smaller surface area of the IHS means that it will be better compatible with existing coolers with round and square-shaped cold plates. Square-shaped cold plates will be the preferred choice but round ones will work just fine too. Noctua has also pointed out the TIM application method and they are suggesting users go with the single-dot pattern in the middle of the IHS for AMD AM5 CPUs.
There are also reports based on the thermal density of the chip that it might run out. Considering that the Zen 4 chiplets are smaller than their predecessor but much denser, they will require a lot of cooling. It looks like that might be one reason why the chiplets are also gold-plated this time to effectively move as much heat away from them and to the IHS. While 170W is the peak TDP rating of the CPU, its PPT or maximum package power is rated at 230W and a 280W figure is used for OC. The figures also include the IO die which should be around 20-25W by itself. Following is a thermal density breakdown by Harukaze5719:
AMD Ryzen 7000 Desktop CPU Render (With/Without IHS):
1 / 11
Another thing that needs to be pointed out is that each Zen 4 CCD is really close to the edge of the IHS which wasn't necessarily the case with previous Zen CPUs. So not only delidding will be highly difficult but the center is mostly the IO die which means that cooling equipment needs to be ready for such chips. The AMD Ryzen 7000 Desktop CPUs launch in Fall 2022 on the AM5 platform. That's a chip that can reach up to 5.85GHz with up to 230W package power so every little amount of cooling will be a must for overclockers and enthusiasts.