<DocScrutinizer05>
EU still pushing for what in the end will be censoring of the internet
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<wpwrak>
(1974) yes, but that is the process per se, not the fluid chemistry
<wpwrak>
(expensive) well, USD 100/l for something that seems to be typically sold in quantities of liters would be expensive
<wpwrak>
(niche) well, could be. but if it has so nice characteristics, wouldn't industrial use of SMT quickly adopt it ? or is everyone happy enough with their existing reflow ovens and it doesn't add a real benefit compared to them ?
<DocScrutinizer05>
I think everyone is happy enough with their existing reflow ovens, since they are paid for, installed, proven and understood
<DocScrutinizer05>
and temp profiles are still an issue with VPS. If only since no chip manuf provides alternative temperature profiles made for VPS
<DocScrutinizer05>
so from datasheet perspective, you're always doing instrument flight with VPS
<DocScrutinizer05>
the profiles in datasheets are for classical hot air reflow
<DocScrutinizer05>
evidently an average component survives temperature gradients higher than the whatever-3°K/s those profiles request for, for preheating. You only can assume that it might be OK to preheat classical to e.g. 160°C and then do VPS reflow to 230°C in virtually no time
<DocScrutinizer05>
note that chill period is more easy to control since the component would cool down too slow when the ambient temperature doesn't allow faster chilling, and to slow gradients are not an issue as long as you're sufficiently far from the peak temperature
<DocScrutinizer05>
very modern (patented) VPS works with different temperature zones, I suspect they use a mix of "galden160", "180", "200" "galden230", which have conveniently different milecular weight to form vapor layers of decreasin temperature with increasing distance from liquid surface
<DocScrutinizer05>
molecular*
<DocScrutinizer05>
you just need to control the amount of liquid you evaporate, for each layer, to avoid the layers getting too thick
<DocScrutinizer05>
of course when going industrial, such a VPS zones machine will get complex, it prolly needs separate tanks for the different liquids, and a distiller to separate the vapors to reuse them
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<whitequark>
DocScrutinizer05: but you can do profiles with VPS
<whitequark>
my temp controller lets you set ramp rate
<DocScrutinizer05>
hmm, hardly
<whitequark>
how so
<whitequark>
controlling ramp up is easy
<DocScrutinizer05>
Galden230 won't evaporate at 220°
<whitequark>
haha of course it will
<whitequark>
have you actually tried the process
<DocScrutinizer05>
not yet
<whitequark>
you can absolutely preheat the PCB
<DocScrutinizer05>
but I read the Galden datasheets
<whitequark>
I can probably prove this to you if I find a second thermocouple
<DocScrutinizer05>
cool
<DocScrutinizer05>
are you using HS or LS?
<whitequark>
LS
<DocScrutinizer05>
that might be the difference
<whitequark>
possible
<DocScrutinizer05>
maybe LS means Low Selective
<DocScrutinizer05>
aka more mixed molecule weight
<DocScrutinizer05>
with 230 just denominating the max temperature
<whitequark>
targeted delivery of HF to your lungs
<whitequark>
wpwrak: also, some real good story behind this unassuming sentence in enwiki: "In May 1924, eleven tons of phosgene escaped from a war surplus store in central Hamburg."
<DocScrutinizer05>
tell me, how would I tell grep's PID before starting it, so I could set this variable correctly - for whatever it's worth if anything at all
<whitequark>
um
<whitequark>
you fork(), getpid(), exec()
<DocScrutinizer05>
LOL
<whitequark>
getpid() is async-signal-safe so you can use it after fork but before execve
<DocScrutinizer05>
indeed, exec works
<whitequark>
it's an absurdly bad design, of course
<DocScrutinizer05>
Distillation range [°C] 222—235 Boiling temperature TRV [°C] 227–233
<whitequark>
"The build-up static electricity, when reaching high values, will discharge into the surroundings with arcing. This could cause pinholes in hoses and tubes causing the fluid to leak."
<DocScrutinizer05>
hehe
<DocScrutinizer05>
very non-conductive fluid
<DocScrutinizer05>
I wonder what funny things you could do with such liquid and high DC voltage
<whitequark>
you could fill voltage multipliers with it
<whitequark>
"In order to detect fluid leaks a halogen leak detector can be used" clever
<DocScrutinizer05>
what is a halogen leak detector?
<whitequark>
oh it's a very simple device
<whitequark>
it has a tip with a needle that has a corona discharge
<whitequark>
all halogenated gases strongly inhibit corona discharge because of their high dielectric strength
<whitequark>
so basically, it beeps when current falls under threshod
<whitequark>
annoying as fuck too, tends to pick up a lot of noise