Live data from Hacker News

Home Chip Fab

sam.zeloof.xyz

81–90 of 136 posts

Re: Home Chip Fab

#81
post #49
post #30

Earlier quoted context omitted.

Good point. The space race would have massive benefits for us on earth in nanofabrication. Just one more bonus point for space.

How does microgravity help in nanofabrication?

It may not be the microgravity that's the major help, but the hard vacuum. Deep space is the biggest, best clean room there could ever be.

Re: Home Chip Fab

#82
post #52

Once space exploration really gets going, mobile chip fabrication is gonna be a pretty big deal.

NASA had a 1980 study° of space fabrication systems where they referred to small, light, hard-to-manufacture parts as "vitamins." These vitamins (ICs certainly, perhaps special sensors or high-quality optics) would likely be the last part of the manufacturing system to be moved from Earth into space due to the complexity (=mass/volume) of fabrication and relative ease of transportation. ° http://www.islandone.org/MMS…

This terminology also got carried on top the self replicating 3d printer world. Any part that cant be produced by a printer is a vitamin.

Re: Home Chip Fab

#83
post #49

Earlier quoted context omitted.

How does microgravity help in nanofabrication?

It may not be the microgravity that's the major help, but the hard vacuum. Deep space is the biggest, best clean room there could ever be.

Wouldn't you have to deal with radiation that you are normally shielded from in Earth`s atmosphere? That may be more difficult to shield from than producing a normal clean room.

Re: Home Chip Fab

#84

Earlier quoted context omitted.

Have a look at [1] https://bits-chips.nl/artikel/small-series-of-chips-profitab... under "E-Beam" for 0.25-micron node and roadmap.

Ok thanks for that. So 500 nm today, moving to 250 nm by the end of the year or early next year. So your 12.5mm wafer can have a 8.8 x 8.8 mm square inside of it, or 78.125 mm^2. If I did the math right that is on the order of 156M transistors given a 4t ram cell that is about 39 million bits of RAM. So basically a pretty useful amount of space for "jelly bean" type applications. A synchronized fab line with a median…

Here is a PDF from 2017 from someone involved with a project wich seems to intend to use this in an (large scale?) innovation initiative in Japan.

[1] www.lip6.fr/public/2017-03-17_Shimizu.pdf

Mentioned are workflows, used tools, intendend audience and goals, estimated prices, nda-freeness of spice models and design rule check, open source, open-cores, github, and so on.

If they really make this widely available, then my mind is blown...

Re: Home Chip Fab

#85
post #20

Please don't dump your solvent down the drain like every Silicon Valley fab did back in the day, poisoning the entire region for decades to come. Just look up how many EPA Superfund sites are in the South Bay due to trichloroethylene, TCE contamination. Dispose of it properly and safely.

> Please don't dump your solvent down the drain like every Silicon Valley fab did back in the day, poisoning the entire region for decades to come. +1 Please develop a workable waste disposal strategy BEFORE thinking about cool disruptive home brew nanofab MEMS/circuit hacks.

There are a few things I don't want disrupted, and my endocrine system is one of them.

Re: Home Chip Fab

#86
post #79

Earlier quoted context omitted.

But is it acceptable to dump wastewater with Cu+/Cl- ions inside? I've read that according to some regulations in some areas, they are considered pollutants and should not be dumped directly to the drainage. Or is it something you can just ignore, because at the end of the day everything goes to a wastewater treatment plant, and your volume/concentration is too low to be considered hazardous, and actually not more ha…

Cl ions are fine; dissolved table salt consists of them, plus some cations. The copper is more of a problem, and I don't know the official answer. I'd think that if you could oxidize it to copper monosulfide (covellite), cupric oxide (tenorite), or even fully hydrated copper carbonate (malachite) if you don't have acid rain, that would adequately protect it from weathering and thus allow you to dispose of it safely.…

First warning with neutralizing acids: You're going to release a lot of heat, make sure you have a large thermal mass to absorb it. Someone else mentioned mixing your ingredients with water first. This is why.

From what I understand the last thing you want to experience is an explosion of hydrofluoric acid.

The internet seems to suggest lime (->fluorspar) or soda lye (->NaF, used for fluoridating water) to neutralize HF, but that's two other substances you wouldn't want raining on your head... be careful out there.

Re: Home Chip Fab

#87
post #75

Earlier quoted context omitted.

> safely dispose of ferric chloride, sulfuric acid, and hydrochloric acid The first step is easy: neutralize them with any base, such as baking soda. You don't need precision, just add a lot of it, and make sure the pH is close to 7 (or beyond, baking soda is not corrosive) at the end. After this step, the solution is no longer acidic or corrosive and much safer to handle. Unfortunately, the next step is tricky. The…

Is this what people actually do? I mean I'm aware I could neutralize them, but Cu is still going to be in there and I still can't pour this stuff down the drain. Then there's ferric chloride which is just nasty stuff that will likely stain everything it comes in contact with. I just want to get rid of it in a fully environmentally safe way.

I'm not sure it is economical, but I had some Sodium Persulfate etchant that was full of copper and accidentally dropped a piece of steel in it. The copper plated onto the steel almost instantly. You could probably use iron filings (or some metal that won't dissolve in your acid) to pull most of the copper out of the acid, and then neutralize. I'm not sure what you would do with the solid copper after that. It might take some effort to get a system that was reliable and economical, but the basic idea of precipitating out the copper before neutralization should work.

Re: Home Chip Fab

#88
I bet there's some overlap with thee the $300 UV resin printer technology that has just become available - they print at 50micron - essentially they're just a TFT cell phone screen with a UV backlight.

Re: Home Chip Fab

#89

Earlier quoted context omitted.

pretty easy really. Add acid to water, then add baking soda to the acidic water until it's neutralized. (no more bubbling), then pour it down the sink with more water. Use appropriate precautions, gloves, goggles, well-ventilated area, etc. Once the acid is neutral, it won't hurt anything in the pipes.

The concern probably isn't the acidity, but the heavy metals and other toxins in the solutions. Pouring tpxins down the drain isn't a good idea.

Yeah it's being talked around in this thread but I think most of the participants seem to get it.

The solvents can be broken down to things that are compatible with the sewer system.

The hard part to deal with is the material you dissolved with the solvent.

Re: Home Chip Fab

#90
This is really cool. Jeri Ellsworth made some videos several years ago about homemade silicon transistors, but it was impractical due to the low precision and large size. Getting down to 5 um is a few orders of magnitude worse than a top end chip foundry today, but it's at least useful and you can fit all of the necessary equipment into a spare bedroom.
Post reply on HN