https://youtube.com/shorts/x5aiu7BTi7E?si=0knTN4-yUVOXSEsy

MitchAlsup1 wrote:
> https://youtube.com/shorts/x5aiu7BTi7E?si=0knTN4-yUVOXSEsy

A quicky search finds the current EUV maximum reticle size is
about 26 mm by 33 mm or 858 mm² (~1 inch by 1.25 inch).

That chip sure looks bigger than that.

EricP wrote:

> MitchAlsup1 wrote:
>> https://youtube.com/shorts/x5aiu7BTi7E?si=0knTN4-yUVOXSEsy

> A quicky search finds the current EUV maximum reticle size is
> about 26 mm by 33 mm or 858 mm² (~1 inch by 1.25 inch).

> That chip sure looks bigger than that.

It looks to me about 4× that reticle limit.

In the early 1980s someone (Amdahl?) was working on wafer scale
lithography, apparently we have now arrived.....

MitchAlsup1 wrote:
> EricP wrote:
>
>> MitchAlsup1 wrote:
>>> https://youtube.com/shorts/x5aiu7BTi7E?si=0knTN4-yUVOXSEsy
>
>> A quicky search finds the current EUV maximum reticle size is
>> about 26 mm by 33 mm or 858 mm² (~1 inch by 1.25 inch).
>
>> That chip sure looks bigger than that.
>
> It looks to me about 4× that reticle limit.
>
> In the early 1980s someone (Amdahl?) was working on wafer scale
> lithography, apparently we have now arrived.....

As part of a sales deal, in 1981 my then employer rented me and
another guy for on-site support to Trilogy Systems,
Amdahl's then attempt to build wafer scale IBM 370 compatibles.
I got to live in sunny Palo Alto all expense paid for 6 months.

Trilogy were building it with ECL macro cells on 3" wafers
with interconnect wires patterned between 0.25" * 0.25" reticles,
trimmed down to a single chip about 2.5" by 2.5" afterwards.

Part of it was inventing a way to dissipate 1200 watts from
the above chips, using liquid freon IIRC.

Also there was no software CAD tools then so all that had to be
invented from scratch too.

They burned through $250 million in seed capital (DEC was one investor)
and closed, merged into Elxsi according to Wikipedia.

EricP wrote:

> MitchAlsup1 wrote:
>> EricP wrote:
>>
>>> MitchAlsup1 wrote:
>>>> https://youtube.com/shorts/x5aiu7BTi7E?si=0knTN4-yUVOXSEsy
>>
>>> A quicky search finds the current EUV maximum reticle size is
>>> about 26 mm by 33 mm or 858 mm² (~1 inch by 1.25 inch).
>>
>>> That chip sure looks bigger than that.
>>
>> It looks to me about 4× that reticle limit.
>>
>> In the early 1980s someone (Amdahl?) was working on wafer scale
>> lithography, apparently we have now arrived.....

> As part of a sales deal, in 1981 my then employer rented me and
> another guy for on-site support to Trilogy Systems,
> Amdahl's then attempt to build wafer scale IBM 370 compatibles.
> I got to live in sunny Palo Alto all expense paid for 6 months.

I really enjoyed my time in "the valley" for the 18 months I was there.
All expenses paid would have been a goodly bonus situation.

> Trilogy were building it with ECL macro cells on 3" wafers
> with interconnect wires patterned between 0.25" * 0.25" reticles,
> trimmed down to a single chip about 2.5" by 2.5" afterwards.

> Part of it was inventing a way to dissipate 1200 watts from
> the above chips, using liquid freon IIRC.

Imagine how quickly a 1 oz hunk of silicon would get hot at 1200 Watts
of input power.

> Also there was no software CAD tools then so all that had to be
> invented from scratch too.

> They burned through $250 million in seed capital (DEC was one investor)
> and closed, merged into Elxsi according to Wikipedia.

There have been similarly large expenditures in AI chips over the last
decade.....to mostly naught.

mitchalsup@aol.com (MitchAlsup1) writes:
>EricP wrote:
>
>> MitchAlsup1 wrote:
>>> https://youtube.com/shorts/x5aiu7BTi7E?si=0knTN4-yUVOXSEsy
>
>> A quicky search finds the current EUV maximum reticle size is
>> about 26 mm by 33 mm or 858 mm² (~1 inch by 1.25 inch).
>
>> That chip sure looks bigger than that.
>
>
>
>It looks to me about 4× that reticle limit.
>
>In the early 1980s someone (Amdahl?) was working on wafer scale
>lithography, apparently we have now arrived.....

Cerebras has a wafer-scale chip in production.

Self healing, and works around defects.

The CS-3 has 900,000 cores and 44GB on-chip memory.

https://www.cerebras.net/

mitchalsup@aol.com (MitchAlsup1) writes:
>EricP wrote:
>
>> MitchAlsup1 wrote:
>>> EricP wrote:
>>>
>>>> MitchAlsup1 wrote:
>>>>> https://youtube.com/shorts/x5aiu7BTi7E?si=0knTN4-yUVOXSEsy
>>>
>>>> A quicky search finds the current EUV maximum reticle size is
>>>> about 26 mm by 33 mm or 858 mm² (~1 inch by 1.25 inch).
>>>
>>>> That chip sure looks bigger than that.
>>>
>>> It looks to me about 4× that reticle limit.
>>>
>>> In the early 1980s someone (Amdahl?) was working on wafer scale
>>> lithography, apparently we have now arrived.....
>
>> As part of a sales deal, in 1981 my then employer rented me and
>> another guy for on-site support to Trilogy Systems,
>> Amdahl's then attempt to build wafer scale IBM 370 compatibles.
>> I got to live in sunny Palo Alto all expense paid for 6 months.
>
>I really enjoyed my time in "the valley" for the 18 months I was there.
>All expenses paid would have been a goodly bonus situation.

I've lived and worked there for thirty five years now. Just got
back from a hike in a nearby redwood forest.

On Thu, 18 Apr 2024 22:41:01 +0000, mitchalsup@aol.com (MitchAlsup1)
wrote:

>In the early 1980s someone (Amdahl?) was working on wafer scale
>lithography, apparently we have now arrived.....

Actually, several companies were. The one mentioned, Trilogy, was the
one that spun off of Amdahl. There was also the company that was going
to make the solid state storage wafer for the Sinclair, the name of
which was Anamartic. Texas Instruments and ITT also researched its
possibilities.

John Savard

On 4/20/2024 11:28 PM, John Savard wrote:
> On Thu, 18 Apr 2024 22:41:01 +0000, mitchalsup@aol.com (MitchAlsup1)
> wrote:
>
>> In the early 1980s someone (Amdahl?) was working on wafer scale
>> lithography, apparently we have now arrived.....
>
> Actually, several companies were. The one mentioned, Trilogy, was the
> one that spun off of Amdahl. There was also the company that was going
> to make the solid state storage wafer for the Sinclair, the name of
> which was Anamartic. Texas Instruments and ITT also researched its
> possibilities.
>

On the other side of things, I am wondering what sorts of densities and
clock speeds are possible with printed electronics on a plastic
substrate (such as PET).

Information on the subject is fairly sparse, but inks seem to be
available (albeit expensive), albeit with some variation as to printer
technology. Seems to be be either organic or inorganic inks, with
inkjet, offset, and screen printing, as the main variations in printer
technology (with different inks for the different methods).

Though, I will assume that by inkjet, they don't mean just using a
repurposed consumer-grade printer (possibly with the ROM's hacked to
allow them to use refilled ink cartridges, with the non-standard inks).

Then again, with these things, they have created a situation where there
are a lot of old inkjet printers around, mostly because it is often
cheaper to buy a whole new printer than to buy the ink refill cartridges
for said printer (vs, say, laser printers where the printer is more
expensive, but the toner refills are more reasonable).

Looking around, it seems some people are instead using the more "office
style" inkjet printers for this (which apparently allow for refilling
the ink cartridges).

Also seems the N and P doped inks are rarer and more expensive than the
conductive metallic and insulator inks.

No information on what sorts of densities are possible; crude guess is
it is roughly a ~ 133333um process, based on the assumption of a 300 dpi
printer (possibly more or less).

If one assumes, say, 6-dots width for a transistor, this would be ~
50x50 transistors per square inch, or possibly ~ 200k transistors per
page...

I guess, if one could get it to run at MHz speeds, this could be enough
for a CPU.

Though, would likely need multiple passes through the printer to print
something like this, say:
Print transistor layers;
Bake the sheet;
Print insulator and metal trace layers;
Bake;
Print more insulator and metal trace layers;
Bake;
...

Possibly, a person could also print vias and then do multiple layers of
transistors per page, possibly up to some set limit.

Not entirely sure how one would go about mapping digital logic onto
printable layers though. This may well be the hard part.

I will make a guess that there are probably no Verilog to
semiconductive-ink-PNG compilers.

....

> John Savard

BGB wrote:

> On 4/20/2024 11:28 PM, John Savard wrote:
>> On Thu, 18 Apr 2024 22:41:01 +0000, mitchalsup@aol.com (MitchAlsup1)
>> wrote:
>>
>>> In the early 1980s someone (Amdahl?) was working on wafer scale
>>> lithography, apparently we have now arrived.....
>>
>> Actually, several companies were. The one mentioned, Trilogy, was the
>> one that spun off of Amdahl. There was also the company that was going
>> to make the solid state storage wafer for the Sinclair, the name of
>> which was Anamartic. Texas Instruments and ITT also researched its
>> possibilities.
>>

> On the other side of things, I am wondering what sorts of densities and
> clock speeds are possible with printed electronics on a plastic
> substrate (such as PET).

> Information on the subject is fairly sparse, but inks seem to be
> available (albeit expensive), albeit with some variation as to printer
> technology. Seems to be be either organic or inorganic inks, with
> inkjet, offset, and screen printing, as the main variations in printer
> technology (with different inks for the different methods).

To determine wire delay per unit length, one would need the LRC values
of the conductor and insulators. Copper on Epoxy allows for transmission
speeds of ½ that of light, and I think you would be resistance limited.

So, we need:: 1) Ohms per square, 2) inductance per unit length, and
3) capacitance per unit area.

> Though, I will assume that by inkjet, they don't mean just using a
> repurposed consumer-grade printer (possibly with the ROM's hacked to
> allow them to use refilled ink cartridges, with the non-standard inks).

> Then again, with these things, they have created a situation where there
> are a lot of old inkjet printers around, mostly because it is often
> cheaper to buy a whole new printer than to buy the ink refill cartridges
> for said printer (vs, say, laser printers where the printer is more
> expensive, but the toner refills are more reasonable).

> Looking around, it seems some people are instead using the more "office
> style" inkjet printers for this (which apparently allow for refilling
> the ink cartridges).

> Also seems the N and P doped inks are rarer and more expensive than the
> conductive metallic and insulator inks.

> No information on what sorts of densities are possible; crude guess is
> it is roughly a ~ 133333um process, based on the assumption of a 300 dpi
> printer (possibly more or less).

300 DPI is 1995 technology, I would be surprised if you could not find
4800 DPI printers. This, alone, changes the lambda by 160×.

> If one assumes, say, 6-dots width for a transistor, this would be ~
> 50x50 transistors per square inch, or possibly ~ 200k transistors per
> page...

Generally, the planar technologies had 6 lambda (min) source and drains
with 4 Lambda gates and one would need 9 lambda to drop a contact on
a source or drain. So, a minimum contacted transistor would be 9+4+9
= 22 lambda wide. Generally one wanted 4 lambda between different
active regions, to the pitch of this minimum contacted transistor would
be 9+4 = 13 lambda.

> I guess, if one could get it to run at MHz speeds, this could be enough
> for a CPU.

> Though, would likely need multiple passes through the printer to print
> something like this, say:
> Print transistor layers;
> Bake the sheet;
> Print insulator and metal trace layers;
> Bake;
> Print more insulator and metal trace layers;
> Bake;
> ...

Your typical 2 layer metal CMOS process in 1.5µ had 200 steps in it.
1) spin on resist
2) bake resist
3) expose resist (mask 1: P-wells and N-well contacts)
4) develop resist
5) etch resist
6) clean wafer
7) ion-implant exposed wafer
8) clean wafer

8 similar steps for N-wells

17) deposit polysilicon
18) bake polysilicon
19) spin on resist
20) bake resist
21) expose resist
22) develop resist
23) etch resist
24) clean wafer

25) spin on resist
26) bake resist
27) expose resist (P-Channel)
28) develop resist
29) etch resist
30) clean wafer
31) P-channel implants (arsenic)

32) spin on resist
33) bake resist
34) expose resist (N-Channel)
35) develop resist
36) etch resist
37) clean wafer
38) N-channel implants (phosphorous)

Then, for each contact layer one has 8 steps, and for each metal layer
one would have 10 steps. Then a thick passivation, then cutting of the
bonding pads, and finally, a back lap of the wafer to clean contaminates
and a 3 atom thick gold sputter so one can solder the Si die to the
package.

So, the problem becomes one of how does one get the pads attached to
the "other" components in the system ??

> Possibly, a person could also print vias and then do multiple layers of
> transistors per page, possibly up to some set limit.

> Not entirely sure how one would go about mapping digital logic onto
> printable layers though. This may well be the hard part.

Straightforward place and route.

> I will make a guess that there are probably no Verilog to
> semiconductive-ink-PNG compilers.

> ....

>> John Savard

On 4/21/2024 5:02 PM, MitchAlsup1 wrote:
> BGB wrote:
>
>> On 4/20/2024 11:28 PM, John Savard wrote:
>>> On Thu, 18 Apr 2024 22:41:01 +0000, mitchalsup@aol.com (MitchAlsup1)
>>> wrote:
>>>
>>>> In the early 1980s someone (Amdahl?) was working on wafer scale
>>>> lithography, apparently we have now arrived.....
>>>
>>> Actually, several companies were. The one mentioned, Trilogy, was the
>>> one that spun off of Amdahl. There was also the company that was going
>>> to make the solid state storage wafer for the Sinclair, the name of
>>> which was Anamartic. Texas Instruments and ITT also researched its
>>> possibilities.
>>>
>
>> On the other side of things, I am wondering what sorts of densities
>> and clock speeds are possible with printed electronics on a plastic
>> substrate (such as PET).
>
>> Information on the subject is fairly sparse, but inks seem to be
>> available (albeit expensive), albeit with some variation as to printer
>> technology. Seems to be be either organic or inorganic inks, with
>> inkjet, offset, and screen printing, as the main variations in printer
>> technology (with different inks for the different methods).
>
> To determine wire delay per unit length, one would need the LRC values
> of the conductor and insulators. Copper on Epoxy allows for transmission
> speeds of ½ that of light, and I think you would be resistance limited.
>
> So, we need:: 1) Ohms per square, 2) inductance per unit length, and 3)
> capacitance per unit area.
>

Dunno there...

It looks like a lot of the metallic inks are silver or copper based.

Not entirely sure how it works. Apparently one needs to bake the sheet
for the components in the ink to turn into their final forms, but around
80-120C is well below the melting points of silver or copper (but, they
apparently somehow sinter at these temperatures).

Would need to have an oven that does accurate temperature control, since
if part doesn't get hot enough, the ink wont set correctly, and if too
hot, the PET substrate might warp or melt, ...

>> Though, I will assume that by inkjet, they don't mean just using a
>> repurposed consumer-grade printer (possibly with the ROM's hacked to
>> allow them to use refilled ink cartridges, with the non-standard inks).
>
>> Then again, with these things, they have created a situation where
>> there are a lot of old inkjet printers around, mostly because it is
>> often cheaper to buy a whole new printer than to buy the ink refill
>> cartridges for said printer (vs, say, laser printers where the printer
>> is more expensive, but the toner refills are more reasonable).
>
>> Looking around, it seems some people are instead using the more
>> "office style" inkjet printers for this (which apparently allow for
>> refilling the ink cartridges).
>
>
>> Also seems the N and P doped inks are rarer and more expensive than
>> the conductive metallic and insulator inks.
>
>> No information on what sorts of densities are possible; crude guess is
>> it is roughly a ~ 133333um process, based on the assumption of a 300
>> dpi printer (possibly more or less).
>
> 300 DPI is 1995 technology, I would be surprised if you could not find
> 4800 DPI printers. This, alone, changes the lambda by 160×.
>

The stuff I was aware of, printer resolution was usually assumed to be
between 72 to 300 DPI.

Apparently (looks up stuff), inkjet typically ranges from 300 to 720 DPI
(with 600 to 1200 for laser printers, and 1000 to 2400 for photo printers).

Not sure of the DPI of a generic office-style inkjet printer (assuming
one gets one of the ones that allows for refillable ink cartridges).

>> If one assumes, say, 6-dots width for a transistor, this would be ~
>> 50x50 transistors per square inch, or possibly ~ 200k transistors per
>> page...
>
> Generally, the planar technologies had 6 lambda (min) source and drains
> with 4 Lambda gates and one would need 9 lambda to drop a contact on
> a source or drain. So, a minimum contacted transistor would be 9+4+9
> = 22 lambda wide. Generally one wanted 4 lambda between different active
> regions, to the pitch of this minimum contacted transistor would
> be 9+4 = 13 lambda.
>

OK.

So, I guess similar would hold if one had a 1200 DPI printer...

But, only 50k for 600 DPI.

Seems like this could handle a lot of 8/16 era CPUs on a sheet.

Though, saw a video talking about it, and they had a printed Cortex-M0
on a smaller piece of plastic (around 4in^2 IIRC), but the video didn't
say what sort of printer or inks they were using, so...

>> I guess, if one could get it to run at MHz speeds, this could be
>> enough for a CPU.
>
>> Though, would likely need multiple passes through the printer to print
>> something like this, say:
>>    Print transistor layers;
>>    Bake the sheet;
>>    Print insulator and metal trace layers;
>>    Bake;
>>    Print more insulator and metal trace layers;
>>    Bake;
>>    ...
>
> Your typical 2 layer metal CMOS process in 1.5µ had 200 steps in it.
> 1) spin on resist
> 2) bake resist 3) expose resist (mask 1: P-wells and N-well contacts)
> 4) develop resist
> 5) etch resist
> 6) clean wafer
> 7) ion-implant exposed wafer
> 8) clean wafer
>
> 8 similar steps for N-wells
>
> 17) deposit polysilicon
> 18) bake polysilicon
> 19) spin on resist
> 20) bake resist
> 21) expose resist
> 22) develop resist
> 23) etch resist
> 24) clean wafer
>
> 25) spin on resist
> 26) bake resist
> 27) expose resist (P-Channel)
> 28) develop resist
> 29) etch resist
> 30) clean wafer
> 31) P-channel implants (arsenic)
>
> 32) spin on resist
> 33) bake resist
> 34) expose resist (N-Channel)
> 35) develop resist
> 36) etch resist
> 37) clean wafer
> 38) N-channel implants (phosphorous)
>
> Then, for each contact layer one has 8 steps, and for each metal layer
> one would have 10 steps. Then a thick passivation, then cutting of the
> bonding pads, and finally, a back lap of the wafer to clean contaminates
> and a 3 atom thick gold sputter so one can solder the Si die to the
> package.
>
> So, the problem becomes one of how does one get the pads attached to
> the "other" components in the system ??
>

I am guessing the process for inkjet on a plastic substrate is somewhat
different from that used for optical lithography on silicon.

But, the information I had seen implies it is mostly printing onto the
sheet, and then baking the sheet so that all the components sinter
together, then more printing, and more baking, for each layer.

Well, unless it is print/dry/print/dry, with baking as a final step
(where dry is done at a lower temperature than bake).

Also not obvious which of the various types of ink one would use, etc...

>> Possibly, a person could also print vias and then do multiple layers
>> of transistors per page, possibly up to some set limit.
>
>
>> Not entirely sure how one would go about mapping digital logic onto
>> printable layers though. This may well be the hard part.
>
> Straightforward place and route.
>

There is a pretty big gap between Verilog and the actual transistors.
But, yeah, in concept, probably some way to compile Verilog to a
netlist, and then to convert the netlist to the various component layers.

>> I will make a guess that there are probably no Verilog to
>> semiconductive-ink-PNG compilers.
>

Though, probably actually TIFF, as one needs a format that can hopefully
specify things in terms of the CMYK system, so that hopefully it prints
stuff with the correct inks, rather than blending them all together...

>
>> ....
>
>
>>> John Savard

BGB wrote:
> On 4/21/2024 5:02 PM, MitchAlsup1 wrote:
>> BGB wrote:
>>
>>> No information on what sorts of densities are possible; crude guess
>>> is it is roughly a ~ 133333um process, based on the assumption of a
>>> 300 dpi printer (possibly more or less).
>>
>> 300 DPI is 1995 technology, I would be surprised if you could not find
>> 4800 DPI printers. This, alone, changes the lambda by 160×.
>>
>
> The stuff I was aware of, printer resolution was usually assumed to be
> between 72 to 300 DPI.
>
> Apparently (looks up stuff), inkjet typically ranges from 300 to 720 DPI
> (with 600 to 1200 for laser printers, and 1000 to 2400 for photo printers).
>
>
> Not sure of the DPI of a generic office-style inkjet printer (assuming
> one gets one of the ones that allows for refillable ink cartridges).

I probably do more high-resolution printing than most of you, since I'm
the leader of the Mapping Commision of the Norwegian Orienteering
Federation.

For any given orienteering map, we need to print very sharp (i.e.
maximum contrast) lines. Both black (road edges etc) and brown
(contours) lines are just 0.10mm wide, and since brown requires a CMYK
mix of either 3 or 4 components, you have to start with a _very_ high
resolution printer to consistently get good results.

2400x2400 DPI is what you really need, it is available on the highest
end print engines (from Xerox and others), but you also need very good
software to generate visually optimal vector to raster conversions (i.e.
like the industry standard Fiery RIP).

1200x1200 laser printers are the new medium/low end standard, you can
get that with A3 size paper at a reasonable price.

Ink jet photo printers typically deliver significantly smaller dot
sizes, but at far higher per page costs.

Terje

--
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"

On 4/22/2024 1:08 AM, Terje Mathisen wrote:
> BGB wrote:
>> On 4/21/2024 5:02 PM, MitchAlsup1 wrote:
>>> BGB wrote:
>>>
>>>> No information on what sorts of densities are possible; crude guess
>>>> is it is roughly a ~ 133333um process, based on the assumption of a
>>>> 300 dpi printer (possibly more or less).
>>>
>>> 300 DPI is 1995 technology, I would be surprised if you could not find
>>> 4800 DPI printers. This, alone, changes the lambda by 160×.
>>>
>>
>> The stuff I was aware of, printer resolution was usually assumed to be
>> between 72 to 300 DPI.
>>
>> Apparently (looks up stuff), inkjet typically ranges from 300 to 720
>> DPI (with 600 to 1200 for laser printers, and 1000 to 2400 for photo
>> printers).
>>
>>
>> Not sure of the DPI of a generic office-style inkjet printer (assuming
>> one gets one of the ones that allows for refillable ink cartridges).
>
> I probably do more high-resolution printing than most of you, since I'm
> the leader of the Mapping Commision of the Norwegian Orienteering
> Federation.
>
> For any given orienteering map, we need to print very sharp (i.e.
> maximum contrast) lines. Both black (road edges etc) and brown
> (contours) lines are just 0.10mm wide, and since brown requires a CMYK
> mix of either 3 or 4 components, you have to start with a _very_ high
> resolution printer to consistently get good results.
>
> 2400x2400 DPI is what you really need, it is available on the highest
> end print engines (from Xerox and others), but you also need very good
> software to generate visually optimal vector to raster conversions (i.e.
> like the industry standard Fiery RIP).
>
> 1200x1200 laser printers are the new medium/low end standard, you can
> get that with A3 size paper at a reasonable price.
>
> Ink jet photo printers typically deliver significantly smaller dot
> sizes, but at far higher per page costs.
>

For printing on paper, yeah, laser printers make sense, and that is what
I am using here...

But, it seems most of the printable electronics stuff, is using
inkjet-printable inks rather than toner.

I had looked into it more, and it seems that most of this stuff was
built around PMOS logic.

Looks like one of the dominant inks in this area is PEDOT:PSS, eg:
https://en.wikipedia.org/wiki/PEDOT:PSS

Things like N-channel inks apparently exist, but are less readily available.

So, this likely this means one would need 3 inks:
copper or silver metallic ink;
insulator/dialectic ink;
something like PEDOT:PSS.

With transistors formed by layering these on top of each other, say:
Source and Drain traces;
P-Channel;
Insulator;
Gate trace.

Say, making sure to print down layers of insulator wherever one does not
want traces to touch.

I guess, in the off chance I bought any of this stuff, might make sense
to first experiment with trying to get traces and basic transistors to
work, since probably getting digital logic mapped to this is going to be
difficult (doesn't seem like there are many existing FOSS tools for this
sort of thing).

Though, I guess, if one can make it look sort of like an FPGA, it is
conceivably possible one could use Yosys or similar for the front-end
Verilog compiler.

Say, one can try to map every possible LUT4 to a predefined pattern, and
then generate a netlist of mostly LUT4's and FF's and similar (similar
to an ICE40 or ECP5). Effectively treating the page like it were an
FPGA. Actual place/route could drop down pre-drawn blocks of pixels, and
then figure out a pattern for the routing layers.

Also seems like the relevant type of printers are more in the $200-$500
range (eg: high DPI and refillable), rather than the cheaper $30-$60 models.

> Terje
>

BGB wrote:

>
> I guess, if one could get it to run at MHz speeds, this could be enough
> for a CPU.

> Though, would likely need multiple passes through the printer to print
> something like this, say:
> Print transistor layers;
> Bake the sheet;
> Print insulator and metal trace layers;
> Bake;
> Print more insulator and metal trace layers;
> Bake;
> ...

A starting point::

https://youtube.com/shorts/-eeazBcavUE?si=nGNykOGIrTsvGGL-

On 5/2/2024 9:23 PM, MitchAlsup1 wrote:
> BGB wrote:
>
>>
>> I guess, if one could get it to run at MHz speeds, this could be
>> enough for a CPU.
>
>> Though, would likely need multiple passes through the printer to print
>> something like this, say:
>>    Print transistor layers;
>>    Bake the sheet;
>>    Print insulator and metal trace layers;
>>    Bake;
>>    Print more insulator and metal trace layers;
>>    Bake;
>>    ...
>
> A starting point::
>
> https://youtube.com/shorts/-eeazBcavUE?si=nGNykOGIrTsvGGL-

Yeah, the most likely ink that would be used for making the transistors
(PEDOT:PSS) is apparently fairly commonly used for printed solar cells
and OLED displays. One could in theory make solar cells and OLEDs using
the same general process.

Though, it is not cheap. At the moment, "poking around at it" is not
really enough to justify dropping around $1k mostly for an expensive
inkjet and a bottle of PEDOT:PSS ink.

Did at least end up buying the parts to make the oven, but they are over
at the machine-shop right now. This was the cheap part, but could also
be used for solder reflow and powder coating, so is easier to justify.

Well, technically, the printable PET plastic is cheaper than the toaster
oven was, but more expensive than a ream of printer paper (and around
10x the cost per sheet).

Well, there are also acrylic sheets (intended for overhead projectors),
but PET has a higher melting point than PMMA. For the baking process,
one wants a sheet that wont melt or deform, and can hopefully tolerate
being soldered onto. The melting point for PMMA being lower than the
melting point for 60/40 solder, but PET being higher.

Though, one would need a temperature-controlled iron, since if the
soldering iron gets to hot, it would also melt PET, so would need to
keep the iron below a limit of around 220 or 230C or so (melting point
of PET being ~ 250C); though in my case, I had already bought a
soldering station with this feature, and also a desoldering gun.

Well, also temperature control is useful for not causing the solder pads
and traces to come off the PCB (say, if one exceeds 220C, then things
like phenolic PCBs are not too happy either).

....

Some likely difficult issues would be things like getting the sheets
loaded back into the printer with sufficiently accurate alignment
between passes.

Like, say, if the sheet alignment was only accurate to around 0.030" or
so, then this would have a significant adverse effect on possible
transistor density (and the DPI of the printer would not matter so much
in this case).

Though, the main likely source of variability here would be in the tray
or paper-feed mechanism.

The place-and-route is also uncertain, but in theory is possible.
Would likely work by getting a Verilog compiler to spit out a netlist,
probably telling Yosys to pretend it is targeting a Lattice ICE40 or
ECP5 or similar.

Would likely need to manually design basic components like logic gates
and flip-flops. Logic gates could be defined for every possible 2->1
truth-table.

Possible LUT2 gates:
0000: Wired to GND
0001: AND
0010: -
0011: Buffer (Ignore B)
0100: -
0101: Buffer (Ignore A)
0110: XOR
0111: OR
1000: NOR
1001: XNOR
1010: Inverter (Ignore B
1011: -
1100: Inverter (Ignore A)
1101: -
1110: NAND
1111: Wired to VSS

Where, for the '-' gates, would need to come up with something.

Here, 0010 and 0100 are A/B mirrors, as are 1011 and 1101 (and logically
inverted from the former). This seems to be some sort of unnamed/unknown
asymmetric logic gate (seemingly an AND or NAND gate with either A or B
inverted).

Mental estimate is that all cases should be possible within 4
transistors and 3 resistors (and seemingly would need to decide between
active-high and active-low logic, though AFAIK typically active-high is
more common).

Could then procedurally generate every possible LUT3 and LUT4. Going
beyond LUT4 would not be likely be plausible with this approach (LUT4
having 2^16 possible truth-tables, LUT5 and LUT6 having 2^32 and 2^64).

Seems like every possible LUT3 should be possible with 3 gates (2 gates
deep), and every possible LUT4 with 7 gates (3 gates deep). Though, it
is likely that many truth tables could be done in less.

A LUT5 would need 15 gates and LUT6 31 gates, they could be possible if
they were generated "on the fly" rather than trying to prebuild and
store gates for every possible truth table.

Though, less obvious how to approach LUTRAM (Distributed RAM) and SRAM
blocks. Might make sense to somehow tell synthesis that the device lacks
any SRAM type blocks, and to use FF's for everything

I am guessing, a LUTRAM cell would likely need to contain some MUX logic
and a collection of flip-flops, and so probably significantly larger
than a bare LUT or FF.

( Though, admittedly, trying to imagine the structure of a LUTRAM cell
is pushing the limits of my visual imagination, and most of what my
imagination is coming up with seems comparably very large... ).

For resistors, most likely option seems to be to make a transistor with
a fairly narrow channel, and then to hard-wire it in the ON state (say,
Gate is wired to Drain or similar).

Internally, could probably represent the logic layers as 16-color BMP
images or similar (likely LZ compresssed to save space, and representing
CMY rather than RGB).

Though, technically probably only need 2 bits/pixel in this case, say:
00: Nothing
01: Insulator
10: Metal
11: PEDOT

Though, would likely need to design the transistors and logic gates in a
graphics editor (probably Paint.NET or similar), with a logical mapping
from pixel color to material.

Say:
White: Nothing
Green: Insulator
Red: Metal
Blue: PEDOT
But, not sure if there is a convention for this.

Final output would likely need to be TIFF or something (for hopefully
direct CMYK control of the printer). Or, maybe try expressing the colors
in RGB (but matched to an inverse CMYK transform), and then hope the
printer doesn't mix the inks too much.

Then again, nothing is to say that the graphics programs and printer
wouldn't go CMYK -> RGB -> CMYK, rendering the use of TIFF effectively
moot in this case (in which case, may as well just use PNG or TGA or
similar).

....