Overclocking AM5 - direct soldering to PCB ?

[Azure_Bram_225]

I wonder if anyone has tried (after delidding) soldering 9950X directly to the PCB, by skipping the AM5 socket mechanism ?

Those things have considerable wire lengths and pins are bent to serve as springs, so there are considerable inductances and resistances involved.
Soldering the chip directly should bring improvements to power rails, but also to high-speed PCIe lanes, memory signals etc.

Has anyone done this ?

 

[KingNosser]

No idea but would only seem a professional overclocker like kingpin or 8pack them type of people would try this to really put out the right information and methods to do such a thing for it to take hold as most people well might delid but I can’t myself see people doing this as the experience isn’t the same or the cost involved isn’t a risk most would want to take onboard themselves.

 

[Meaker]

The CPU pinout on the bottom is not designed as a solder contact on the desktop chips.

You can get the HX chips that are this (see the minis forum boards) but there is bios compatbility to think about there. You'd also need an interposer to go from whatever socket pingout to BGA of the chip. That will add interference and resistance.

 

[Azure_Bram_225]

The CPU pinout on the bottom is not designed as a solder contact on the desktop chips.

I know but it looks like AM5 chip could be reballed and then soldered directly to a PCB like a BGA.

 

[Meaker]

I know but it looks like AM5 chip could be reballed and then soldered directly to a PCB like a BGA.

2-3 chips and the facilities required to attach a silicon die to a package are horrendously expensive, it's in a different league to soldering a BGA package to a board.

 

[Azure_Bram_225]

2-3 chips and the facilities required to attach a silicon die to a package are horrendously expensive, it's in a different league to soldering a BGA package to a board.

Why would I need either ?

Take an 9800X for example, flip it around, apply solder mask over the bottom side with circular pad openings over it and reball it like you would reball an ordinary BGA. After that, one should be able to solder it just like a BGA.

 

[Meaker]

Why would I need either ?

Take an 9800X for example, flip it around, apply solder mask over the bottom side with circular pad openings over it and reball it like you would reball an ordinary BGA. After that, one should be able to solder it just like a BGA.

The spacing and size of the pads is not designed for that. I think the surface tension of the odd shape and the difficulty in heating that size pad is going to do you in.

 

[Azure_Bram_225]

The spacing and size of the pads is not designed for that. I think the surface tension of the odd shape and the difficulty in heating that size pad is going to do you in.

I would think that the spacing should match. And the shape mismatchshould be solved on both sides (bo9ttom side of the CPU and top side of the PCB with a soldermask with circular pad holes.

 

[Meaker]

I would think that the spacing should match. And the shape mismatchshould be solved on both sides (bo9ttom side of the CPU and top side of the PCB with a soldermask with circular pad holes.

They are just so out of the norm, they are not rounded, you would be asking for trouble.

 

[Azure_Bram_225]

They are just so out of the norm, they are not rounded, you would be asking for trouble.

As I said, I'd apply soldermask with round holes over them.
On the chip as well as on the PCB.
So I'd get round pads to reball and solder.