<azonenberg>
How much of that actually went into audio though lol
<bart416>
we were losing about 400W in thermal emissions
<azonenberg>
lol
<azonenberg>
As in, 400W in heat dissipated on the control board?
<bart416>
yes
<azonenberg>
Because i bet the arcs dissipated a LOT
<bart416>
on the FETs
<bart416>
yeah
<bart416>
But we reached 141 dB at 1m distance at one point
<azonenberg>
Wow
<azonenberg>
How was the sound quality?
<bart416>
not that great
<azonenberg>
i forget, arc speakers are good at HF but suck at bass?
<bart416>
The FETs had trouble switching that much power
<bart416>
yeah
<bart416>
but above 100W using FETs isn't the best of ideas xD
<azonenberg>
you mean BJTs?
<bart416>
nah, the FETs were having issues
<bart416>
the BJTs not so much
<azonenberg>
i thought you said no fet drivers?
<bart416>
yeah, we used BJTs to drive the FETs
<azonenberg>
oh
<bart416>
in a push/pull config
<bart416>
we had to only allow the FETs on for fractions of a second or they'd fry
<bart416>
we were using all of them above recommended values xD
<azonenberg>
So you were operating them in linear mode?
<azonenberg>
or just the Ron was too high
<bart416>
well, we were using a high voltage transformer obviously
<bart416>
But after a few microseconds it saturates
<bart416>
resulting in a DC shortcircuit
<bart416>
If that were to occur the FETs would blow
<azonenberg>
lol
<azonenberg>
So the problem was the transformer was underpowered for 2kW?
<bart416>
The only thing keeping the entire setup alive was the current limit of the supplies though heh
<azonenberg>
LOL
<azonenberg>
The whole thing just sounds like a terrible idea
<bart416>
you constantly saw the current limiter indicator turn on heh
<bart416>
and you could follow what FETs were doing the job on the meters of the supplies (they still have analog meters in them cause it's easier to spot certain things on those if you were wondering :P )
<azonenberg>
Lol
<azonenberg>
Reminds me of the time I tried arc welding/soldering with a 5A 30V benchtop PSU
<azonenberg>
using really narrow solder as the electrode
<bart416>
or endeavour wasn't helped by the lack of a LRC meter that could determine the self inductance of the transformer
<azonenberg>
i actually almost got a joint once lol
<bart416>
heh
<azonenberg>
made some spectacular sparks and burned the scrap PCB i was testing on
<bart416>
we tried a q meter as well, that one also failed
<azonenberg>
but the 0603 cap i tried soldering was too big
<azonenberg>
maybe on 0402 or 0201 i'd have a chance
<bart416>
We ended up having to use a network analyzer to find the impedance >_>
<azonenberg>
um, wtf
<azonenberg>
You guys are crazy
<azonenberg>
Not that I'm not too
<azonenberg>
just saying :p
<bart416>
The q meter didn't go low enough in frequency to be able to find the value, lol
<azonenberg>
lol
<bart416>
We had to try a few network analyzers though
<bart416>
Only the old HP one delivered heh
<azonenberg>
You mean like mHz?
<azonenberg>
yes, thats a lowercase M :P
<bart416>
Dunno, I didn't do the math
<bart416>
I was too busy preventing the FETs from melting each other
<bart416>
We were using large metal bars as cooling fins
<azonenberg>
lol
<bart416>
worst part was, one of our professors was like "wtf are you guys doing?"
<bart416>
We were expecting to get shouted at at that point
<azonenberg>
lol
<azonenberg>
and what happened?
<bart416>
He gave us a couple of high voltage probes so we could hook up a scope to the output end of the transformer xD
<azonenberg>
'OL
<azonenberg>
Very nice
<bart416>
Actually quite interesting waveforms
<bart416>
Though luckily we put our entire setup in our faraday cage
<bart416>
And you want to know the worst part?
<bart416>
TI makes FETs that can switch this sort of load on their own...
<bart416>
best part is the price of that thing lol
<bart416>
we intend to xD
<azonenberg>
Also
<azonenberg>
While you're having fun with HV
<bart416>
hough our next step is actually to use liquid nitrogen
<azonenberg>
get a nice big cap bank
<bart416>
*Though
<azonenberg>
like, 25 kJ or so
<azonenberg>
And discharge it all into an unsuspecting fruit
<azonenberg>
I can say from experience the result is quite impressive
<azonenberg>
Though you might not want to be standing too close ;)
<bart416>
If we use liquid nitrogen we don't have to give a fuck about this entire maximum switching time
<bart416>
the junctions can't die if they're at -180�C xD
<azonenberg>
lol
<bart416>
But yeah, the entire setup was acting as one huge transmitter :S
<azonenberg>
Lol
<azonenberg>
how much EMI were you pickign up from it?
<azonenberg>
and how big a faraday cage do you guys have wherever you are?
<bart416>
uhm, how big is our faraday cage, with or without the anti reflective spikes?
<bart416>
counting with them, about 2m high, 6m long, 4m wide.
<azonenberg>
ok, thats loarge lol
<bart416>
Without, 3m high, 8m long, 6m wide
<azonenberg>
large*
<bart416>
A lot of RF research goes on there so yeah
<bart416>
They actually need it
<azonenberg>
I see
<bart416>
We actually have a remarkable amount of RF equipment
<bart416>
Quite a lot of high power transmitters, excellent receivers
<bart416>
Loads of network analyzers that go really high in frequency
<bart416>
Scanners that most colleges/universities would commit a murder for
<bart416>
We also have a few of the network analyzers that go low in frequency
<bart416>
(Lower than 1Hz)
<bart416>
Most of it HP/Agilent, Tektronix and R&S
<azonenberg>
<1 Hz? How long do those things take to get a measurement
<bart416>
I'd say there's a few million euro worth of equipment in there
<bart416>
Ages
<azonenberg>
i was gonna say
<bart416>
We also have quite a lot T&M prototypes though
<bart416>
So you shouldn't be amazed if the front panel comes lose
<azonenberg>
Lol
<azonenberg>
Yay prototypes
<bart416>
Actually, can't complain
* azonenberg
remembers fun times with semiconductor prototypes
<bart416>
Agilent prototype devices are not a bad thing, insane measurement ranges lol
<azonenberg>
Lol
<bart416>
"oh yeah I want 10 GSa/s"
<bart416>
^stuff like that
<bart416>
But the bastards feel the need to not let use in that lab until this year >_>
<azonenberg>
lol
<azonenberg>
They dont want to share the toys
<bart416>
I guess
<bart416>
Sort of understandable though
<azonenberg>
You mean the fact that it probably costs six or seven figures?
<bart416>
Yeah
<azonenberg>
The guy at the RPI cleanroom who runs the FIB is very protective of it
<azonenberg>
nobody is allowed to touch it except under his personal supervision
<bart416>
Well yeah, they didn't actually have to pay for most of it
<azonenberg>
unless they have hundreds of hours on the SEM
<azonenberg>
with no problems whatsoever
<bart416>
Well yeah, most of our equipment was sponsored or donated
<azonenberg>
The SEM is a zeiss supra 55 that we got for what i'm told was a steal
<azonenberg>
it was included as almost a freebie when they bought the FIB
<azonenberg>
Which was full price around $1.5M iirc
<bart416>
lol
<azonenberg>
The supra was used, a demonstration model that was well taken care of but not brand new
<azonenberg>
probably would have sold for a paltry quarter million
<bart416>
demonstration models aren't all that bad if they're not abused
<azonenberg>
The guy who runs the SEMs used to work for zeiss
<azonenberg>
He knows his stuff
<bart416>
same for spectrum analyzers or DAQ cards
<azonenberg>
As in, he was a lead engineer
<azonenberg>
who did demonstratoins of their top-of-the-line equipment
<bart416>
Ever had the fun of playing with one of those 20000 euro DAQ cards?
<azonenberg>
and got to take the supra home to RPI's cleanroom when they finished demoing it
<azonenberg>
And no, i havent
<azonenberg>
i dont do much daq
<bart416>
one of my class mates had to use that >_>
<bart416>
I'd be scared as hell
<azonenberg>
you mean that you'd break it?
<bart416>
Yeah
<azonenberg>
Yeah, i'm always paranoid on the SEMs
<bart416>
They're fragile as hell
<azonenberg>
Especially the old Jeol
<azonenberg>
Which isn't worth nearly as much
<azonenberg>
But the supra has a camera inside the chamber so you can see if you're about to smash the sample into the objective
<azonenberg>
No such luck on the jeol lol
<azonenberg>
At least, the old tungsten one
<bart416>
I mean, I know those network and spectrum analyzers aren't that fragile, infact you can jam the input probe into the power socket and it'll probably be fine, but still
<azonenberg>
the jeol FESEM does have one, i think
* azonenberg
wants a FESEM at home
<bart416>
But you probably understand what I mean?
<azonenberg>
Yeah
<bart416>
My scariest experience was operating a synchrotron though
<azonenberg>
i've used equipment that costs more than my college degree did :p
<azonenberg>
and how so
<bart416>
Uhm, you're operating a device that accelerates sub atomic particles to a respectable fraction of lightspeed and then smashes them into something...
<azonenberg>
Lol
<azonenberg>
what i mean is, how automated is it?
<azonenberg>
in terms of the probability of, idk
<azonenberg>
pointing the beam somewhere other than the intended target
<bart416>
Oh, that's not a problem
<bart416>
It's just, you need to decide when the beam is ready to be released onto the target
<bart416>
the power bill of operating one of those things for even a few minutes is nuts
<azonenberg>
you mean directing it from the storage ring to the target?
<bart416>
yes
<azonenberg>
And i see
<bart416>
I mean, sure you simply wait until you reached the calculated parameters
<bart416>
But at that point the decision is still up to you
<azonenberg>
I see
<bart416>
If you fuck up it has to gather up momentum again for a day or two
<azonenberg>
A day? o_O
<bart416>
you can't just switch it on again
<bart416>
After every use it needed quite some maintenance
<azonenberg>
Oh lol
<azonenberg>
i thought you meant it took that long to accelerate
<azonenberg>
and maintenance how so?
<bart416>
Sample has to be replaced, source materials, verifying for contamination, ...
<bart416>
Reconfiguring the system also takes a while
<azonenberg>
i see
West0n joined #homecmos
<bart416>
I can't imagine what the people who operating the LHC must feel in terms of stress
<bart416>
+ our synchrotron was fairly old
<bart416>
I mean, it wasn't bad for its job (material research)
<bart416>
But it wasn't unlikely that some part was going to fail
<bart416>
And some of the sensors were also unreliable actually now that I come to think of it
<bart416>
Actually, without the older technicians I doubt we could have kicked that thing to life
<azonenberg>
material research?
<azonenberg>
not physics?
<azonenberg>
So what are you doing, testing how material X behaves when irradiated?
<Thetawaves>
so cold fusion is a real thing now
<Thetawaves>
?
<azonenberg>
?
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<West0n>
Have you ever had an issue with photoresist pooling up azonenberg
<West0n>
I got some spray on stuff
<West0n>
I spray it on evenly
<West0n>
And it always drys as a small pool
<azonenberg>
Thats why i dont spray it
<azonenberg>
I dilute with acetone and then spin coat
<azonenberg>
if you keep spinning till its mostly solid (doesnt take long witih the surface area of a micron-thick film)
<azonenberg>
it doesnt have a chance to pool
<West0n>
Will plain dilution reduce pooling?
<West0n>
Any way to stop it without a spin coat?
<horizontally>
azonenberg: how likely do you think it is to be able to spincoat hundreds of nanometers?
<azonenberg>
Dilution will result in a thinner film
<azonenberg>
since the viscosity and solids content are lower
<azonenberg>
and if you use a solution with a low solids content, low viscosity, and high RPMs?
<azonenberg>
Easy
<azonenberg>
i've gotten films sub-100nm of tantalum oxide
<azonenberg>
getting good uniformity at these scales can be a little tricky
<azonenberg>
But it was a tannish color that for SiO2 would mean around 50nm
<azonenberg>
Ta2O5 is higher refractive index so it was likely a bit thinner
<horizontally>
wow sub-100nm!
<horizontally>
is polyamide usually a photoresist?
<horizontally>
or just a coating?
Thetawaves joined #homecmos
soul-d joined #homecmos
<bart416>
azonenberg, since when is material research not physics?
<bart416>
The goal was to test the materials in extreme conditions
<azonenberg>
i see
<azonenberg>
and it's just that i've never seen matsci folks dealing with high energy particles
<bart416>
It's rather important to know how materials behave if you're going to irradiate them
<soul-d>
oh he released the wikileaks thing
<bart416>
Or worse :p
<azonenberg>
Oh, that guy
<soul-d>
and that movie where american soldiers
<soul-d>
play cod
<soul-d>
but 18 month's of solitary confinedment american way ?
<azonenberg>
FYI i do not endorse any politician currently in office
<azonenberg>
I abstained in the last several elections because i disliked all of the candidates enough i couldn't vote for them in good conscience
<bart416>
<soul-d> but 18 month's of solitary confinedment american way ? <-- clearly yes
<azonenberg>
So by abstaining I have the satisfaction of knowing that no matter who is in office
<azonenberg>
I didn't vote for him
<soul-d>
heh yeah most of time doesn't realy mather
<soul-d>
anyhow thats off topic just woke up found this news kinda distrubing that people that show mistakes get treated this way it shows the mentality of people in power
<azonenberg>
That show mistakes?
<azonenberg>
Or that swear an oath to protect their country and then violate that trust?
<azonenberg>
Because he's a pretty clear example of the second
<soul-d>
you think it's ok for us soldiers to go on shooting randomly for fun of it ?
<azonenberg>
No
<soul-d>
and yes
<azonenberg>
But it's supposed to be handled through disciplinary channels
<soul-d>
sure
<soul-d>
believe that yourself
<azonenberg>
And going outside the chain of command is not your place
<soul-d>
yeah round about talk
<azonenberg>
The point is, if you see something you think is wrong you're supposed to contact your commander
<soul-d>
that is typical Rhetoric relegious way of thinking
<azonenberg>
not the nearest newspaper/leaker you can find
<soul-d>
thats doesn't work on that scale
<soul-d>
he will be just replaced and afther a bit fired and moved out the system
<azonenberg>
And guess what, in war people make mistakes
<azonenberg>
But there's no need to parade them around the world
<azonenberg>
You discipline those involved but that's the end of it
<azonenberg>
I guarantee for every publicly reported incident there were ten more that never saw the light of day
<azonenberg>
while those involved were still held responsible
<soul-d>
i like to check that end of story
<soul-d>
cause thats not how the dark world goes around
<azonenberg>
But guess what
<azonenberg>
Who appointed you the army's babysitter?
<azonenberg>
I thoguht so
<soul-d>
the army exists for sole purpose of me
<azonenberg>
And if you can't see the whole picture (read: higher up the chain of command) how do you know what you're actually seeing?
<azonenberg>
For all you know it's a training exercise on how not to act
<soul-d>
thats the point if they don't tell me how i know they don't have other interest how do i know people are not signing up so they can kill random people (they do )
<azonenberg>
Yes, they try to weed them out in training but some will always get through
<soul-d>
yeah like most things
<soul-d>
on 9/11 where trainings acts
<azonenberg>
But the same could be said of any military
<soul-d>
and they din't know the difrence :')
<soul-d>
i see your point
<azonenberg>
So who gains from this? What's done is done
<soul-d>
you do know they simulated 9/11 on 9/11 ?
<azonenberg>
You can't change it, all you can do is cause unnecessary chaos
<azonenberg>
So best to let it lie and not cause even more harm
<soul-d>
since there is money involved someone will profit
<soul-d>
heck
<soul-d>
all weapons of egytian revolution
<soul-d>
are usa
<soul-d>
or backdrop
<azonenberg>
So what? The russians sold quite a bit to the afghans
<soul-d>
to keep usa out i presume ?
<azonenberg>
Through numeroous middlemen
<azonenberg>
Some of whom didnt do as told
<soul-d>
since they aren't there for the 15 trillion in material stuff
<soul-d>
neither oil
<azonenberg>
Enough, this channel isn't here to talk politics
<soul-d>
must be humentary stuff
<soul-d>
true wanted to get cup off coffe ages ago :P only wanted to show how usa treats people without any kind trial but i geuss in light of above thats all allowed :)
<azonenberg>
If I leaked classified information to the press I'd expect no less
<soul-d>
but this is why everone else in world hopes on the demise of the us of a ?
<soul-d>
wel not hoping
<soul-d>
jsut watching the live show
<azonenberg>
Certainly not cushy accomodations and release on bail while waiting for them to decide whether to execute me or not
<soul-d>
the thoguht alone that you consider execution say's plenty
<soul-d>
i din't even think of that
<azonenberg>
Treason in combat? That's been the standard
<azonenberg>
for centuries
<azonenberg>
i can't say this case is any different
<azonenberg>
I don't know enough about the case to be certain of anyone's guilt but if convicted that's what I'd expect
<azonenberg>
What if the same person had leaked documents about troop movements to the enemy?
<azonenberg>
I would actually expect a summary execution on site
<soul-d>
then you could have called it treason for starters
<azonenberg>
What else would it be?
<soul-d>
but exposing people shooting radom people
<soul-d>
but then again he din't know might be secret training op
<soul-d>
and funny thing is you can start war based on lie's fabricate them with fake imagery but then if someone in the war comes exposes said military it's treason :)
<azonenberg>
Doesnt matter how the war starts
<soul-d>
but in end i don't care i just wanted to mention that your country is crumbling apart not mine
<azonenberg>
Once it's happening, you have to finish it
<soul-d>
thats not how it works :) you can even as american say " i am wrong "
<soul-d>
or " i have lost "
<soul-d>
whatever hurts less
<soul-d>
but thyen again starting somthign waht can't be finished was the plan
<azonenberg>
What do you expect to do, say "oops, sorry"
<azonenberg>
walk away
<azonenberg>
and expect to not be followed by a few thousand angry mujaheddin?
<soul-d>
hey not my friends and family "proctecting america"
<soul-d>
thats my friend
<soul-d>
is your own fault
<soul-d>
maybe not go in there and starting to show guns ?
<soul-d>
now they do hate you
<soul-d>
afther you killed most of their family
<soul-d>
anyhow someone read something about not going into discussion on political topics with american's ;) with that ill grab some coffee and drop the subject let you focus on smaller problems :P
<horizontally>
hey azonenberg, i found out we have a professional spincoater nearby that has ramp, etc. settings. i'm gonna use that but i don't want to use their expensive deep uv light source
<horizontally>
so i'm going to try a halogen bulb (and maybe later a black light) and photoresist. is photoresist cancerous? what photoresist do you use? positive/negative? i heard you use glade to print the photomask, will anything do?
<azonenberg>
Re safety, read the MSDS for your specific resist
<azonenberg>
In general you will want good ventilation when coating, the solvents are somewhat nasty
<azonenberg>
But they are usually pretty safe to handle once dried
<azonenberg>
But thats just a rule of thumb, the MSDS is the authoritative source
<azonenberg>
Also, if you are not exposing in the same facility that you are coating
<azonenberg>
Make sure you have some way of moving the coated wafer around without exposing it to ambient UV light
<azonenberg>
or getting too much dust on it
<horizontally>
we have a room with gold lights
<azonenberg>
Yes, but are you exposing there?
<horizontally>
yeah
<azonenberg>
Oh, ok
<azonenberg>
I actually have two sets of lamps in my living room lol
<azonenberg>
one with white and one with yellow bulbs :p0
<azonenberg>
The yellow ones only cover a few key spots like the workbenches, not the whole room, but it's enough to get work done
<horizontally>
i'm going to bring in my little cardboard box with aluminum foil on the inside and do contact lithography with a halogen bulb
<horizontally>
it's an OSRAM 12V 100W that releases UV
<horizontally>
but i think it's meant to be a white light source
<azonenberg>
I've used halogen lamps before
<azonenberg>
they're wideband but get the job done
<horizontally>
why not a black light?
<azonenberg>
just be advised they do run hot
<azonenberg>
blacklight is an option
<azonenberg>
most of them peak around 365nm ish
<horizontally>
so why did you pick halogen?
<horizontally>
how do you protect yourself from the uv in either case?
<azonenberg>
Halogen lamps dont emit enough UV to be a health concern, the bigger risk is the IR since its a fire hazard (the bulb gets quite hot)
<azonenberg>
Blacklight is also safe as long as you dont stare at the lamp for extended periods of time
<azonenberg>
the ones you want to be careful around are short wave UV
<azonenberg>
like mercury vapor germicidal lamps
<horizontally>
so i only want to deal with resists that are in that near uv area
<azonenberg>
i have those in a closed box
<horizontally>
but i also want to be able to get down to like 50 nm thick layers
<azonenberg>
and UV goggles for the rare unavoidable exposures
<azonenberg>
First off
<horizontally>
and since the color charts are repeatable, it's going to be tough to easily characterize that
<horizontally>
er not repeatable but they repeat
<horizontally>
they are periodic
<azonenberg>
the injectorall resist is 365 to 405nm peaks sensitivity
<azonenberg>
So its near UV
<azonenberg>
However
<azonenberg>
Why in the world would you want a 50nm layer of resist
<azonenberg>
it won't block anything
<azonenberg>
usually you have a micron or so of it
<azonenberg>
the only time you'd want a deep submicron film is if you are etching a film of comparable thickness
<azonenberg>
But it never hurts to be thicker
<azonenberg>
the only reason not to have a very thick resist film is that it limits your min feature size by a bit
<azonenberg>
but unless you want submicron features
<azonenberg>
In which case you are a bit beyond me ;)
<azonenberg>
That, plus a bluray diode, could do some pretty cool stuff
<Thetawaves>
Moving Magnet Rotor. The solid rotor is rigider than coiled one, any harmful resonance does not occur. The carbon steel shaft is got from a junk motor (D=2, L=45), and neodymium magnets are got from scraped hard disks. The magnets are cut and bonded to the shaft and then shaped with a water-cooling grinder. The shaft should be thin and light as possible to minmize the rotor inertia.
<Thetawaves>
jesus
<Thetawaves>
azonenberg, it will take significant effort to duplicate that work
<azonenberg>
I'm fully aware of that
<azonenberg>
I've been working on my current fab process for around a yea lol
<azonenberg>
year*
<azonenberg>
And direct write litho would represent a quantum leap in mask fab capability
<horizontally>
azonenberg: i want submicron thicknesses. i found a cool paper that covers how to control the thickness of the film i want to deposit in addition to the width and height
<Thetawaves>
gotta find the magnets
<horizontally>
ceramics?
<horizontally>
you can find those at ace
<Thetawaves>
ceramic magnets?
<horizontally>
if you want a strong magnet, you're probably better off making your own electromagnet
<azonenberg>
horizontally: neodymium magnets are not hard to find
<azonenberg>
Thetawaves: why, though?
<azonenberg>
sorry, horizontally
<azonenberg>
why do you need submicron films?
<horizontally>
azonenberg: thicknesses. to investigate some things about lighting devices i can't go into unfortunately (NDA) :(
<azonenberg>
But in that case you want a film of something else
<horizontally>
a professor i know is really into something cool that he won't tell me but he wants submicron thickness control
<azonenberg>
That you can pattern with photoresist
<azonenberg>
The resist should be as thick as you can possibly handle
<azonenberg>
If you want a transparent layer of a submicron film i suggest glass (SiO2)
<horizontally>
you can't get 50nm thickness? or 100nm thickness?
<azonenberg>
Emulsitone Silicafilm can go down to that thin
<azonenberg>
Photoresist would be hard
<horizontally>
but i want to be able to take it off later too
<horizontally>
do you use hf to get the sio2 off later?
<azonenberg>
I havent used silicafilm myself but it's not as dense as thermal oxide
<azonenberg>
dissolves quite quickly in HF
<azonenberg>
even dilute (3% range)
<azonenberg>
so you can even pattenr it thorugh a photoresist mask using HF
<horizontally>
i've had bad experiences with etching
<horizontally>
i think it's that i'm not diluting stuff enough
<azonenberg>
I've been able to HF etch tantalum oxide
<azonenberg>
my mask did degrade eventually, its very strong (maybe 10x lower etch rate than SiO2)
<horizontally>
how would you measure the thickness of your spincoated photoresist?
<azonenberg>
Usually, i dont :p
<azonenberg>
For other stuff you can go off the color
<horizontally>
i'm really hoping that method works because anything else is going to require me to invest more time in stuff i'm not super interested in anyway :\
<azonenberg>
the vendor usually gives numbers for approximately what range you should be in
<azonenberg>
for a given RPM and concentration
<azonenberg>
then you can use the color to solve for the slight +/- 10% or so you might get due to process variation
<azonenberg>
and get a number good to within 50-100 nm
<azonenberg>
often better, with practice
<horizontally>
what photoresist do you use again?
<Thetawaves>
i'd be able to build that galvo if i got the magnets
<West0n>
Commercial galvos are cheep
<azonenberg>
my photoresist was gotten from injectorall.com
<azonenberg>
i believe it's shipley photoposit SP24D but they rebottled it so i cant be certain
<horizontally>
how did you settle on that one?
<horizontally>
and where did you get it from? can you pick up photoresist from electronics surplus stores?
<azonenberg>
The only one i could find from a nearby vendor
<horizontally>
or like a hardware store?
<azonenberg>
Lol
<azonenberg>
i wish
<horizontally>
fuckk :\
<azonenberg>
They were the only company i found in the northeastern USA that sold it mail order in small volumes
<azonenberg>
places like fisher scientific etc will sell you just about anything
<azonenberg>
... by the liter
<azonenberg>
and idk if you know what the going price for a liter of photoresist is, but that stuff isn't cheap lol
<azonenberg>
then hooked up a ballast and was good to go
<azonenberg>
Those do emit enough of the deep UV (185/254nm) that you want to avoid direct exposure
<azonenberg>
they can cause both sunburns and eye damage
<azonenberg>
so you'll want to shield the enclosure and ideally wear yellow UV-blocking glasses when in use
<azonenberg>
i found a pair from edmund optics that are like five or six nines density below 500nm wavelength
<Thetawaves>
what kind of lens would you use for a galvo setup?
<azonenberg>
No idea, i havent researched that much
<azonenberg>
its on the todo list but i've been very busy
<Thetawaves>
yeah i went to edmund but i'm at a loss for what i would need
<Thetawaves>
biconvex?
<azonenberg>
No clue
<azonenberg>
i have their catalog but i dont know what half the stuff in it is lol
<azonenberg>
the only thing i've bougth from them was the UV goggles which were a pretty easy buy
<horizontally>
azonenberg: how would you test that the bulb is working?
<horizontally>
i guess you look at the current draw through the bulb
<Thetawaves>
i developed a visual model of the lenses required
<Thetawaves>
mount the setup on a stand above the spin coat machine
West0n_ joined #homecmos
<Thetawaves>
you would not have to touch it
<horizontally>
azonenberg: also, the air is going to get pretty heated up by one of these UV bulbs right?
<horizontally>
so in addition to the enclosure am i going to need some way of removing heat out of the enclosure?
<berndj>
horizontally, personally my default opinion of pretty much any unpolymerized organic polymer chemistry is that it's carcinogenic. there are invariably radicals involved, which is never good news.
<berndj>
and just looking an DNQ for one, that looks rather a lot like a nucleotide base, too much for comfort
<horizontally>
it seems so hard to believe that carbons and hydrogens with maybe a carbon ring or two through in can cause cancer
<horizontally>
but i don't know anything about biology
<berndj>
and varying levels of "bad" of course; you get stuff that's guaranteed to give you cancer on even a little skin splash, and other stuff that doubles your risk if you bathe in it
<horizontally>
fuck i hate nanotech
<berndj>
we worked with one of the nastier things one in undergrad biochem - used for DNA sequencing - rather an intimidating feeling working with stuff like that
<berndj>
you'll also get ozone from that sort of UV won't you?
<horizontally>
well azonenberg linked me to a bulb that somehow doesn't make uv
<horizontally>
i don't know how or why
<berndj>
a UV bulb that doesn't make UV?
<azonenberg>
back
<azonenberg>
and what do you mean, doesnt make UV?
<azonenberg>
it was just a link of the spectrum
<azonenberg>
they were advertising a UV-C bulb that filtered out the 185nm wavelength
<azonenberg>
which is what produces ozone
<azonenberg>
My bulbs are unfiltered so you do get a nontrivial amount of it
<azonenberg>
254nm does not produce ozone afaik
<azonenberg>
also, re the DNA sequencing nastiness
<azonenberg>
berndj: ethidium bromide?
<azonenberg>
berndj: also, DNQ is bound into the resin afaik
<azonenberg>
i dont think its free
<azonenberg>
The MSDS for my resist lists the solvent as being a possible carcinogen but not the solids
<berndj>
ethidium bromide sounds familiar, but not familiar enough to stand up and shout, "bingo!"
<azonenberg>
Orange fluorescence under UV
<azonenberg>
Used for staining DNA
<berndj>
you're right, DNQ is pretty much immobilized. i think mainly to avoid diffusion, which would ruin resolution. but i expect it isn't totally-100%-immobile
<azonenberg>
Unfortunately it has a nasty habit of injecting itself into any DNA within reach
<azonenberg>
I mean, you want t oavoid getting it on you
<azonenberg>
obviously
<azonenberg>
But its nonvolatile
<azonenberg>
The solvent is what you want to be more concerned about
<azonenberg>
as its both flammable and has vapors
<azonenberg>
Thats actually the main thing i'm building my local exhaust setup for
<berndj>
oh, i was just about to say... isn't the solvent... water?
<azonenberg>
No
<azonenberg>
In my resist is' a bunch of organic compounds
<azonenberg>
its*
<azonenberg>
2-ethoxyethyl acetate, n-butyl acetate, then a few percent each of xylene and toluene
<berndj>
but i think water has some major role in things?
<azonenberg>
Water is used in the reaction somewhere but i think it picks it up from the atmosphere
<azonenberg>
You dont need much
<berndj>
yeah
<horizontally>
man azonenberg knows so much
<azonenberg>
I just read a lot
<azonenberg>
and play around a lot
<berndj>
he knows everything!
<berndj>
actually i meant to ask you, since IIRC you aren't really formally trained in EE (or are you?): how did you get into electronics, as in actually building stuff that works?
<azonenberg>
Playing around
<azonenberg>
i was doing simple stuff with 555s when i was like 12
<azonenberg>
then got out of it for a while due to lack of supplies
<azonenberg>
then started doing more serious stuff with MCUs when i met some folks in the electronics club at school
<berndj>
i'm stuck in no-man's land: 555s seem not worth doing, and MCUs way too intimidating!
<azonenberg>
simple low-end PICs are not scary at all
<azonenberg>
you can get them in DIP and program them in C
<berndj>
that's probably what i should be doing
<horizontally>
MCUs are intimidating? why? what's your background?
<berndj>
actual software and mostly only armchair electronics :-/