Scratching a CPUs internal silicone die to see what happens! Gotta say, I thought it was gunna be wayyy more fragile need new thermal paste? check out YeesterPaste and all my thermal paste accessories! www.yeesterpaste.com
The "top" of the CPU is actually the bottom of the die. It's called flip chip so the electrical connections and circuits are pointing down. And since back side power or power via isn't used in current CPUs there is actually a lot of extra silicon substrate which you would have to grind trough to actually do any damage to the internal circuit. Also the silicon wafer is quite hard. Which makes it quite scratch resistant but also easy to crack if too much uneven pressure is applied.
You are mostly correct. Which side is facing up is determined by the packaging process and design of the die. Note: some wafer go through back grinding to make them thinner.
@@chefhearne I did mention flip chip which is the way most high end ICs (including CPUs, GPUs, FPGAs, Cipsets etc.) are packaged. Often when impetence and heat are key. Although yes I should have mentioned that not all ICs are made this way (for the topic of CPUs: especially old CPUs from the 8 & 16 Bit era) PS: I did hear that some go trough grinding althoug to my knowledge AMD had some problems with this as it made the die crack too easily.
@@Ether_VoidSubstrate is quite correct. You have to cut through the substrate layer before you get to the diffusion layers. Original post is more correct than using the word wafer. Because he's talking about damage to the circuitry.
So all of the „hot parts“ are on the opposite side? I guess it works out but on the other hand you’d want to have the hot parts as close to the radiator as possible, no?
@@pete5405 While the interconnect resistance is a factor, most of the power is consumed while switching. That happens at the substrate level directly. That heat will diffuse itself fine through the substrate to the IHS and to the cooling solution. On the other hand, interconnect layers have plenty of dielectric material between traces that has very low thermal conductivity, so it's not ideal at all for heat diffusion. Flip chip design also makes connection to pads much easier, because the pads are on the same side as the top interconnect layer. So when you look at all of this, flip chip design is the obvious solution.
@@pete5405 but yes in Heavy OC sometimes they grind the die a little to optimise heat transfer but the results aren't impressive and it takes a lot of mechanical resistance...
Please allow me to contradict you. It's the other way around. The flip chip have all the base layer (where transistors are) on top, having a better heat transfer with the IHS. More on that, the die gets power through the micro bumps (at the highest level of the die, bottom when looking at the chip) through the interposer and through BGAs of the CPU and finally, through the motherboard's pins. The layer he is scratching, it's not that thin due to mechanical stress that has to endure to not crack the die. Source: I'm an engineer in this field.
Even if it did scratch, it would probably still work. All of the circuits and etching are on the other side of the die. The die is really face down, so they can solder connections to that square green board and then to the motherboard. The side you were scratching is really the back of the die and is just for heat transfer to the integrated heat spreader and then the heat sink. At the factory, they actually grind that side down so there is less silicon for the heat to travel through. Some overclockers sand that side down even further for a few degrees cooler temps.
Silicon is at about 7 on the hardness scale, with your typical steel tools being about 4-4.5. Additionally, the surface of the CPU die is quite smooth, so the knife just glides over it and doesn't do any damage. You'd need something like Quartz at a 7 (which is actually Silicon Dioxide) or Topaz at an 8 to do any real damage.
Even if we use the crappy mohs scale and pretend it's remotely scientific, stuff in the high 60s rockwell C would be like 7.5-8 Utility knife blades are up there in hardness, yet it didn't scratch it despite mohs saying it should... Almost like that scale is only really good for getting an idea of what kind of rock you picked up (what it's intended for
The lid is there to evenly distribute weight of a clamped down heatsink so it doesn't crack/chip the core under pressure. Before lids were used, if you didn't apply the pressure evenly, you could crack a corner off the chip which would kill it. -PC Builder from the 90's
Not always. Sometimes you could chip a corner off of the CPU and have it still function normally. The die was ~0.5 mm thick and all the important components are on the bottom. A tiny chip in the corner that didn't go all the way through wouldn't be good; but it could still function.
I remember reading in a forum that the top part of the chip is just a protection, obviously when it breaks due to pressure it is of no use but when it is a minimal scratch or micro bumps on the corners of the chip it still works. generally. . I'm not sure what I said, like I said I read it on a forum.
Это абсолютная правда. То же самое с ГПУ, я ремонтирую технику подобного рода (не считая чего-то нечеловечески тяжелого и дорогого, вроде reball или восстановления дорожек на плате), в большинстве случаев царапины или мелкие сколы ничего не сделают SoC, но эта часть участвует в теплоотводе, так что стоит подумать. К примеру, есть видео на канале HappyPC (русский канал), где скальпировали 13600К и стачивали его die.
Tots correct. There is a top coat thermoplastic that is wear and corrosion resistant. Also, depending on design and packaging, it could be upside down.
@@tkd4 What do you mean different motherboard? It's the Maximus VI Hero (LGA1150) in all shots. If you mean the cooler wouldn't fit then yeah, you can't mount it, but he also didn't mount it.
It's a crystal material made of silicon. Very hard surface, and very brittle, like most hard materials. That's why you can hardly scratch it with metal, but easily break off a corner with a big heatsink assembly.
silicon is a very hard material but most hard materials are easy to crack cause of a lot of internal stresses that form during cooling exactly like glass
@@nitroknife9881 Modern chipsets are not made with acid etching, the process is just far too imprecise components that are atoms widths apart. Acid etching is part of a multitude of processes in the production timeline, but that is for the photoresist, not the pattern in the silicon. The way that they etch the pattern onto a silicon die is using a process called EUV photolithography. EUV stands for Extreme ultraviolet. Photolithography is the process of using light to etch patterns onto a substrate. I'm not going to get into crazy technical stuff here, but if you're interested in the technology I really recommend looking it up, it's super interesting. But yeah, in simple terms, they use EUV and condense the light into an extremely fine laser using molecularly flat mirrors, to then etch the pattern into the silicon wafer. Note: I promise I'm not trying to sound like an ass I'm just going to school for this stuff and I find it really interesting and want to talk about it!
@hakimmohamad6216 it's people misunderstanding, it's not any kind of hardened layer - the silicon is a monolithic block where the components are created by etching holes inside and then diffusing other materials into the silicon. The surface is polished to help make sure there are no voids in the thermal interface, the nitride layer the other user mentions is not for hardening, but to create a surface solder will bond to rather than the normal surface tension
@@hakimmohamad6216 Yes, from 4th gen to 8th Gen Intel chose to use thermal compound for ease of manufacture, its why there was a hobbies scene of Delidding and using liquid metal that some claimed had up to 15 degree temp changes. After 8th Gen they have gone back to solder to wring out all they can as they are running hotter every generation
So fun fact. When CPU's are manufactured, they're done so "upside down," then when they're done being manufactured, they're fliped back over and affixed to the substrate. That way there is a "" thick ""... relatively thick... Layer of silicon with nothing in it. No traces, no transistors, just a "slab" of silicon. Thats for rigidity and structure..... And for bad ideas like this 😂 Basically if there is any imperfections there's material ontop of the actual components of the CPU to protect it if any polishing needs to be done to the die
Technically, it can be fragile but also hard at the same time. In fact, Hard objects (such as hardened steel) is actually quite fragile and will shatter under the right circumstances.
@@soundspark nope. Delided CPUs. If not mistaken Intel did it with one of their i7s. It was a refresh and they sanded down the die and used a thicker heat spreader. As a matter of fact I think gamers nexus did a vid with kingpin doing it.
@@soundspark at extreme levels of overclocking you sand down the die and then direct-dia cool the CPU. It's done when targeting absolutely minimal thermal resistance so you can have better temperature control.
@@KRAFTWERK2K6 no this is for world records. It's like racing with computers. Every little bit helps and it's a hell of a lot of fun once you're good at it
The reason these things are not fragile is obvious. One of the main reasons is that the pressure the Cpu has to handle. If it was fragile enough the cpu could melt overtime!
Btw in most CPUs (up until now at least) the die is actually flipped The face that got etched, cleaned and had the wiring on it gets flipped into the PCB to make contact with solder points, if you can call them that.
@@mleise8292 It also gets rid of the fragile gold wires that used to be bonded to metal pads on the outside of the die. So now you can attach the solder bumps everywhere in an even array and not have all your power delivery and data along the perimeter of the die. Original pentium and pentium MMX used gold wire bonding, but with pentium II and onwards they flipped the chip and went with bare, naked die; before realising that wasn't a good idea and using an IHS.
the transistors are on the bottom few micrometers / nanometers of the die (since the die has to electrically connect to the package), so if you _did_ manage to scratch the die (say, with a diamond scribe or something) it probably wouldn't do anything
It helps that the actual circuitry is on the underside of that piece of silicon. Scratching it shouldn't hurt it all that much, so long as you don't crack it. It's a very hard material too so it doesn't scratch easily anyway.
fun fact the front side of the silicon, where all the wire bonds are made, are on the face down side to make contact with the breakout board. what you see after delidding is the backside of the silicon wafer. so scratching it, while ill advised, isn't going to damage the nanostructures on the other side.
You can scratch it pretty good and it will be fine. It’s protected to some depth on the silicone the active part is on the middle/bottom. I personally have sanded it down to some extent with fine grit 8000 sand paper and used gallium as a thermal compound. Basically nothing can compete for thermals.
you might be surprise as those silicones is also resilient, I have my laptop CPU with liquid metal for 2 years straight, it leave a deep stain and make the surface kinda rough. but it still works fine
Yeah, a few folks have said it - this die is 'flip-chip' mounted, which means the silicon surface with all the components and interconnect is facing down onto the contracts in the package. What you are scratching at is actually the back of the 'bulk' silicon wafer which has no manufactured parts on it.
as long as you don't crack it, it should be quite resilient even if you did scratch it a bit. There's a fairly thick layer of regular silicon on top for support purposes during manufacturing.
It is even possible to scrape down half of the chip because the cpu itself is on the underside of the silicone. The most of the material is for strength so that it is possible to handle it and for heatspreading and transfer.
back in the days when all CPU's were direct die cooling, people would freak out about mounting an HSF on their CPU (this was around the time water cooling was just starting to be a thing). I remember buying a brand new Athlon XP 2000+, and then bending the mounting on the HSF (which was the very high end ThermalTake Volcano 9) just so it wouldn't crack the die. Mounting has come such a long way. I would feel completely confident in direct die cooling a modern processor, not because of the CPU being fragile, but because mounting hardware is just so much better then it used to be, and easier to attach. Socket A vs Socket AM4 or AM5 is completely different.
The silicon wafer itself is several microns thick, where as the etched devices are only angstroms thick, and most importantly on the other side of the wafer. You do risk creating a fracture line by scratching it though. Thermal stress can propagate the crack, and you will be screwed if that happens.
Extreme Overclockers usually sand them down to improve thermals, same with GPU's, just need to be careful, truth is it's quite a thick layer. You just need to be careful and not put too much pressure on one side of the die when sanding (making it uneven and have bad contact).
The transistors are on the bottom of the die. Some extreme overclockers actually remove the top layer of the die with sandpaper to help cool it better, and their CPUs still work after that.
I do believe there's a fine layer of inert silicon above the doped and processed CPU part of the silicon die. X3D chips have a layer to even out the heat and pressure footprint covering the stacked memory.
transistors and all the metal layers are actually on the other side of the silicon. it is called flip-chip. there is nothing of importance on the top layer. (but soon things will change, with backside power delivery, so do not try that on the chips coming next year)
It’s fragile, but not to scratches. It’s most likely cracking or chipping. Just like screens, a plastic screen will be harder to crack but easier to scratch. While a glass screen is easier to crack harder to scratch
It's a flip-chip, so the transistors and interconnects are on the opposite side of the die substrate. You're only scratching the blank underside of the die .. of course that won't affect it. The silicon substrate is usually 0.4mm thick anyway!
Hardness is one thing while brittleness is another thing. Usually the harder the material the more brittle it is, so it cannot withstand deformation. If you bend it it will crack. Another thing is that the die that we see is actually the bottom part and the part that makes the magic happen is contacting the pcb. If you happen to scratch it, you’ll only lose thermal transfer efficiency. It might lose performance because it can’t cool enough, but that’s it. Oh and if you use Liquid Metal it will fill the crack and it will be like nothing happened
The fact is that some people lap the die. I don't recommend it since anything can go wrong. It just turns out that the silicon is harder than steel. I don't know where silicon is on the hardness scale but diamonds, tungsten carbide and sapphire are some of the hardest substances and I would expect some damage to just about anything with them.
Silicon is like glass which is harder than the metals you are using to scratch, actually there usually is glass (SiO2) in microchips, although maybe not so much these days as there was a switch to high-k dielectric materials when transistors got so small that quantum tunneling became a problem.
Silicon is derived from sand. Sand, on the mohs scale of hardness, is an 8 to a 9. Meaning, you need to try it with sandpaper(I would try >400 Grit). The knife only has a mohs hardness of around 5, sometimes 6 if you have a good steel.
Scratches that you cant feel with your nail are usualy fine, deeper scratches that you can feel with your fingernail can be fine sometimes. In the company i worked for we threw them away just to be sure. If you have cracks and chips on the die it means your cpu is probably dead.
I use to work in a factory processing silicon wafers and as I remember, we use what's called a dicing machine which uses diamond tipped saw blades spinning at tens of thousands of RPM to precisely cut through these things.
That isn't a bare die as it is straight from the slicer. There is a layer of protective silicon (or maybe some composite) that protects the actual die and helps with immediate heat dissipation. The bigger problem would be cracking more than scratching, as the die and protective coating are fused together, if the coating cracks, so does the die. Scratching the top will affect thermal performance, but it won't brick a die.
All ASIC/cpu/gpu have a protective coating. Like gold. Scratching the surface does nothing unless the component is designed to have something fused to that surface/bonded. The only risk of directly touching that cpu is static transfer. Take something SHARP and actually scratch surface.
That's the bottom of the die. If it was the top, you'd see a bunch of gold wire bonds leading to the pin. If that was the top, just scrubbing it with that qtip would have likely caused damage due to abrasive dust particles.
That's the back silicon anyway. This is flip-chip bonded to the interposer, the active circuitry is on the other side of the die, covered in an epoxy encapsulant.
Silicon Crystal, especially as pure as it is in microchips, is incredibly hard. Since its a Semiconductor and not a metal, it has a true crystalline structure that gives it this hardness. You are gonna need carbide tools, or other crystalline abrasives to scratch it. Try Sandpaper, with silicon dioxide or aluminum oxide. That should work. Scratching it alone wont hurt it, since the logic is just beneath the surface that is bonded to the green pcb. Scratches will make it more prone to cracking, though. A glasscutter could probably nick it enough to break a chip in two.
CPU die's are laser cut from silicon wafer's. The wafers are cut from artificial grown silicon cristalls. Its much harder then glas. So you will need diamonds or saphire to scratch it.
Video idea, instead of breaking then next CPU you send the parts to your fans in a giveaway but the catch is it is all taken apart and the fans have to put it rogether
Almost all semiconductors, now, are passivated. That is the top layer is silicon dioxide (glass) grown on top of all the other layers. If you used a harder tool to scratch it, as opposed to a screw driver or dull box cutter, it could get damaged. Glass is harder than steel. Use 80 grit sandpaper next time.
Silicon is fragile in the same way glass and ceramic is, I.E. it's somewhat hard to scratch but easy to shatter. Bend that die a little bit and it will crack, particularly if you put pressure near the corners. In order to scratch it you need something harder than it, and silicon dioxide is very hard.
Silicon has a Moos scale hardness of 7. So it would be possible to scratch only with some insanely high carbon steel, or simething like a corundum or a diamond
They aren't etched, they're deposited. The wafer gets coated with "resist" that gets cured during photolithography (an image of the layer is projected on the resist) and the uncured stuff is washed away. Then the metal is deposited on the silicon. After deposition, the resist is reapplied, and the process starts over. It's like 3d printing, but with angstroms instead of millimeters!
This was obviously the back of the wafer. No bonding pads or wires at the edges. The fact that you didn't do any damage just shows that the other side is well supported so you didn't bend the die. (which would cause cracks on the etched side)
You could try spark plug ceramic it should scrach it, and google supports that: In general, aluminum oxide is considered to be a harder material than silicon.
