λ-Bridge Thermal Conductor

Sounds like the concept is to provide a thermal path from a small size "signal" conductor to a large conductor such as a ground plane.

I have no comment on its efficacy or otherwise.

"Designed to direct heat to thermal ground planes, heat sinks, or other points of thermal interest, help protect adjacent components from hot-spot thermal loads, and improve overall circuit reliability, the series exhibits high thermal conductivity, low thermal resistance, and capacitance so low that the devices are virtually transparent at RF/microwave frequencies."

Connect to a large copper pour? Better yet cover it with solder. Add lots of vias and another copper pour on the bottom.

Yes, good. Another question comes up, what schematic symbol to use for this part? We know the PCB footprint.

How about a resistor or a capacitor? The resistor can be 100 Gohms or the capacitor can be 0.01 pf. Add a note to the schematic to explain what the part is for. I've seen heat sinks added to schematics and they have no ele ctrical conductivity. I've seen mounting holes added and they aren't even components in the BOM.

Is this really so hard or unusual?

The original part was a Q-Bridge, by AT Ceramics. It's a great idea, but they are fairly expensive.

I've considered them for taking the heat out of a tiny surface-mount part that needs electrical isolation, out to a big surrounding ground pour. AlN has a great ratio of thermal conductivity to capacitance.

I'd show it as a capacitor.

Kinda neat. But spendy

GH

Maybe something like the plate exchanger would do:

A solid rectangular block should provide a good pictogram of what it is.

NT

angers

NGERS.png

I like the simplicity of this one, and it should not get confused with othe r established symbols because it is unlike them:

The Unicode Lambda is not coming thru to me (λ), so I don't know if th e following will either:

??????? ? ?? ? ?? ? ?? ? ?? ? ???????

It looks okay in Notepad++ using Deja Vu Sans Mono font.

changers

HANGERS.png

her established symbols because it is unlike them:

the following will either:

Nope, not at all. Viewing it in regular view I can see the symbols, but th e spaces are off because it is a proportional font. If I view it in a mono spaced font the characters show as codes, not the symbols.

changers

HANGERS.png

her established symbols because it is unlike them:

the following will either:

Since there is no standard for it in EE, who cares, use what you want.

NT

ASCII version: Heat Exchanger: . . .------. . | |\ | . --| | |-- . | \| | . |______|

df

exchangers

XCHANGERS.png

is.

other established symbols because it is unlike them:

f the following will either:

Exactly. It's not like anyone else is going to understand your symbol. Th is is one of the cases where a word is worth a thousand pictures.

Thermal __ --|__|-- Bridge

Ok, two words...

Perfect, I like it! Better aligned in CAD.

If you want to put something inside the box to show it is not the same as a resistor or capacitor or whatever, I would use three vertical, wavy lines. Like three S letters but not so curved, like heat rising. But the words are what count.

a resistor or capacitor or whatever, I would use three vertical, wavy line s. Like three S letters but not so curved, like heat rising. But the word s are what count.

Three (or two) waves are also filters. (At least one has a slash, typically ).

I think you're right to include text outside the box, if it is a small box. No one will know what this is otherwise, as it is a unique and new sort of part.

I don't like empty boxes. (FPGAs and CPLDs, processors exempted.) I like sy mbols to be symbols---I would try to some kind of simple graphic. My temper ature ICs look like analog thermometers, not empty boxes. I have put a T in side the thermometer graphic. While I gave a "boxed" symbol, It is even bet ter if it can be made w/o a box (for a simple two-terminal part). Another i dea in Unicode: ?????

My opinion is that a symbol should be

1. Simple
2. Compact
3. Distinct (unique)

Even though I'm calling it an "exchanger," I wouldn't use an "X" inside a b ox because of confusion with a mixer/multiplier. (I was toying with some ot her ideas.)

What should the designator be?

Designator: TX (thermal exchanger) Can be confused with "transmit"

Designator: HX (heat exchanger) Seems okay. Unfortunately, H is "Current dependent voltage" in spice

Designator: XH (exchange heat) H, as second, carries it away from a crystal. X is a subcircuit in LTspice, so it can be generally defined there

Designator: XT (exchange thermal) Shimano mountain bike gruppo. Ugh

I "vote" XH.

f the following will either:

the spaces are off because it is a proportional font. If I view it in a mo nospaced font the characters show as codes, not the symbols.

This is an interesting Unicode sidebar...

I didn't have much hope the spacing would come through the news reader. (I assumed copy-paste to a text editor.) I use G-groups and even though the re ad font is not mono-spaced.

The Unicode "Box draw" section includes all the old code page 437 glyphs, a nd more. Box Draw requires mono-space, of course.

You indicate you have a problem as you "view it in a monospaced font the ch aracters show as codes." I do not have this problem in Notepad++ with Deja Vu Sans Mono font. Are you saying getting things like "U+2500"? You didn't call out your editor/viewer. I can get Notepad++ to render nonsense if I sw itch the encoding to ANSI. My encoding is set to UTF-8 to render properly. I can copy the text (from the the G-group reader into Notepad++ and it rend ers properly. What Newsgroup reader do you use? Does it support Unicode?

Here it is with 5 of the more obscure box draw elements replaced with more commonly utilized glyphs (square corners replace arced and the diagonal is replaced with backslash): ??????? ? ?\ ? ?? ? ?? ? \? ? ??????? ^^^ This actually spaces correctly in the G-Group *writer*, which appears a s a kind of Courier.

Win's reply had a code replacement, as follows:

=94=80

I don't know his newsgroup reader-writer, but it definitely didn't like the Unicode. He couldn't write the "?" either.

Hah, I can view it but not send it.

Looks like a fuse.

Yes, I like that.