We designed a gadget using 0306 caps, like 0603s but metalized on the long side, for low ESL. We now want to try some different values, ballpark 200 pF, but can't find anything that low. Yup, we've searched the usual suspects.
Does anybody know of some niche source for these?
The alternative is a row of 0402s soldered broadside in parallel. That works, but it's a little hard on manufacturing.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Probably best to design those out. Side-contact caps are mostly used for very efficient bypassing. Other markets aren't served AFAIK. Even if you find some it'll probably remain a boutique part, with high MOQs, long leadtimes and unobtanium phases.
-- Regards, Joerg http://www.analogconsultants.com/
Hi, John -
Try
type 0306 into their search thing and see if it comes up with anything useful to you.
Good luck.
John S
They do mostly larger values, 1 nF minimum as I recall.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
I need super low ESL. It's in the new laser driver, where the current will be 10 amps per nanosecond, which makes 10 volts across every stray nanohenry.
We were thinking of maybe standing up a parallel-plate capacitor and heaping solder on both sides, across a very small gap in a wide trace. But that would probably be hard to manufacture, too.
Sigh, looks like a lot of 0402s.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Give it some time :-) With frequencies going higher I wouldn't be surprised if we see more of these caps in a short while.
-- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
Mine got done yesterday but I didn't have to go below the nanosecond barrier (yet).
Well, there is 0201 and even 01005 :-)
See if you could use some of their smaller value X2Y caps:
-- Regards, Joerg http://www.analogconsultants.com/
we use 0402 decoupling on an fpga it fits the pitch and the void the foot print. That's one cap per millimeter I'm sure a machine that can mount 0201 would have no problems mounting them closer
-Lasse
X2Y caps, yes, but at a steep premium. Side contacts are less likely because you can just as well go to 0201 and smaller for most RF stuff. Except some power stuff but that market is just too small to be served.
-- Regards, Joerg http://www.analogconsultants.com/
I wonder how you would best mount them then broadside across a gap in the trace with input to end pads, out from center pad?
-Lasse
One way would be to come in on a wide trace from layer X into the ends, then from layer X+1 to the centers. The traces would shunt some more because they also act as a capacitor. Must be adjacent planes that are close together. This is the kind of stuff where one has to think about special circuit board, very thin.
-- Regards, Joerg http://www.analogconsultants.com/
If one looks at a "Linnux" memory stick for the HP Xeon commercial computers, one will see an entire row of 0201 caps (and resistors)along the edge near the connector fingers. They look like a via from a distance because they are so small. It actually requires that you look at it with magnification to see them well.
I'd say a bank of 0201s will be cheaper than forcing long side manufacturing processes on the makers. Or they will pre-integrate "banks" of them together ala resistor banks for designers for easy placement and less headaches.
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maybe an array would work:
-Lasse
Looks good. Less metal too. Allows a larger cm stack across a smaller gap.
They'll be playing with the metallization media of the layers next. What do they make the conductive plate layers from? Those they people...
Carbon related surface treatments mixed with silver or gold or such maybe would be something to try. Took a while before they used copper in chips. Probably some similar issues with vapor depositions too.
Stack a multi-layer of that carbon/gold stuff up and see what you get.
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