@ThePhoton I think ordinary PCBs have that property too

hi

does fuzzy system and fuzzy logic have any thing to do with circuits?!!

are they related in anyway?

The relation is fuzzy

@parvin The electrical and magnetic variables in a circuit (current, voltage, ...) follow Maxwell's equations (theory of electromagnetism)...Kirchhoff's law are actually an approximation of Maxwell's laws (lumped parameters and rather low-frequencies)

@parvin So in fact, the answer is no...There is nothing inherently "fuzzy" about the differential equations governing E(t) and B(t) and such

@parvin Fuzzy logic has more to do with a way of decision making...You could implement a fuzzy logic controller with circuits (analog and digital) but again, the process needs a "defuzzification" step so the result could be realizable via physical elements (en.wikipedia.org/wiki/Defuzzification)

@PlasmaHH You never said anything about any special kind of PCB.

@ThePhoton it seems "substrate like PCB" is recognized as a special kind in the industry

@PlasmaHH Never heard of it

Is it meant to mean "PCB material with behavior like alumina"?

The way I look at things, FR4 is just a different kind of substrate. So saying "substrate-like PCBs" is like saying "tree-like elms".

@ThePhoton I know a bulletproof surefire way of putting a beer at the top of the US list. Print a bulls-eye target on every can. Makes the can more entertaining to shoot.

@NickAlexeev PBR already has that reasonably round blue target on it.

@ThePhoton I failed to find a lot of information, but they seem to mean silicon

@PlasmaHH Any links you can share?

@ThePhoton not here from the phone. Just Google for the term. I saw it first mentioned as new way for the upcoming S9 to get more battery space

@PlasmaHH I think this image explains what they mean:

They're talking about using the techniques used to make BGA packages to make the whole board.

good morning

I have a question which is a bit open and not fit for the Q&A format (yet)

@Christoph ok

I'm planning to build a vapor phase reflow oven, and I'm unsure about safety regarding immersed heating cartridges (to heat up and evaporate galden), which I could get for 12 V DC or 230 V AC.

this is the basic setup:

@PlasmaHH Probably it means some kind of sintered material. Possibly thin film metal patterning. Possibly some kinds of embedded/printed/think-or-thick-film resistors and capacitors.

@Christoph This might be more an engineering.SE question than an electronics.SE question.

I would expect you mainly need to have a heater rated above the boiling point of the liquid its immersed in.

so there's a stainless steel container with some galden in it, and an immersed heating cartridge. It might touch the container, and it might also get in contact with nearby thermocouples. If I use 12 V DC to supply the heaters, I'd need some pretty beefy power supply (probably two PC PSUs). Voltages would be non-lethal, though. 230 V AC heaters, on the other hand, would be easier to supply with a relay

I've sorted out most of the thermodynamic aspects

@Christoph You probably want to keep the heater fully surrounded by liquid, not let it touch the walls of the bath.

The heaters must be fully surrounded, otherwise the galden might overheat and decompose at some locations. This is really about electrical safety for the case that the heaters do touch the container

electrically insulating the heaters will be pretty hard; I'd need some kind of plastic that can handle temperatures well above 230 °C, up to 290 °C to be on the safe side. The usual high-temperature stuff is out of the game (PTFE, PEEK, ...)

leakage current for the 230 V heaters I have in mind is specified as < 0,5 mA

@Christoph ceramics?

hm...

anything specific? Should be doable with common household tools

some sort of glass silk tube might work, but it would also disturb heat transfer and increase the risk of overheating the galden

sounds feasible, with the downside that those rings would raise the heaters from the bottom. So I'd need more galden fill the container to the minimum level, which is more expensive

but getting back to the initial question - don't you think it's possible to make this safe even with 230 V heaters?

@Christoph That's an "ask a guy with a license" kind of question.

probably

@ThePhoton embedding passives would probably be a way to increase density.. current phone PCBs already seem as dense as possible

@PlasmaHH They are pretty amazing.

Alumina is pretty affordable as a material

@PlasmaHH Embedded passives has been a thing a while now. I am currently working on a design for a DC/DC TEC control module that embeds most of the passives in a 2mm substrate

Long term project though

Wurth can do it with nearly any passive as well

I have not received any up or even down votes for my last 7 or so answers, and many more down votes now that I passed 5,000. Apparently I have lost my touch and no longer suitable to answer questions on EE.SE. I am deleting my profile and moving on.

@Sparky256 Please don't. Who cares about fake internet integer assignments? Inexperienced folks like me could get a lot of help from answers of people like you