I use my phone as an e-reader. It's great because I always have it with me (well, I forgot it at home today) and can read anytime I have a few minutes to spare. I wouldn't carry any book with me everywhere.
I expect so, nickel is megnetic. Electroless nickel is pretty thin, so not very magnetic.
Probably enough to register on a MICR reader etc.
-- When I tried casting out nines I made a hash of it.
e even through the entire via? Don't they coat the inside of the via with something that conducts for the plating to stare all through the via from t he beginning of the electroplating bath?
The PCB resin is formulated with a catalyst, that makes a thin layer of cop per in a no-electricity-required (electroless) plating step. That makes a conductor that supports the (lat er step) electroplating.
Earlier PCB manufacture used a mask/platinum catalyst variant of electroles s plating.
Plating solutions are intended to make even, smooth, pure metal. It kinda sorta gets close to that goal. Recipes are... bizarre and usually secret.
Even so boundary layer friction effects will dominate in smaller holes. They won't get their fair share of the action.
-- Regards, Martin Brown
Rick C wrote in news: snipped-for-privacy@googlegroups.com:
The same way they plate 'chrome' on plastic for model cars. The holes must get 'primed' somehow to attract and accept the plating molecules.
Also the drilled hole size and the finished, plated hole differs as plating is a build up. And PTHs are a lot thicker than say a 5uinch gold plating is. It is at least a couple mils I think.
I found this...
John Larkin wrote in news: snipped-for-privacy@4ax.com:
is
ENIG is about solderability and being lead free. It was NEVER about being more conductive or carrying away heat better... or at all.
Nickel conducts fine for circuit traces. If conduction were any kind of issue, we would have perfected a way to use Silver decades ago.
We do not see plastic metal matrix 3D pronted traces yet as that medium does have conduction problems, but ANY real metallic path has sufficient conductivity for the task. I mean, we are not putting iron down and calling it conductive.
Copper, with Nickel and then a couple microinches of Gold are methods to make the PCB more perfectly coplanar for use in modern fine pitch and SMD technologies.
We do not see any HASL fine pitch layouts, because HASL has coplanarity problems which look like a mountain range to those component leads.
On technical subjects it allows you to see state of the art papers in some cases even before they are officially published. Major breakthrough announcements have timed embargoes - like with the black hole image.
Scans of classic reference books some of them with associated computer code are now online by the publishers. Old versions but still useful. That certainly beats typing it in again or ordering a disk/CD.
Even my old favourite intro to bipolar transistors published by Ferranti in 1969 to popularise their e-line transistors is out there on the net.
History is always written by the victors. I favour physical reference books more because they are not dependent on mains power to work.
-- Regards, Martin Brown
ias
es
.nto
etrate,
lo it's not really diffusion.
For some value of "small". My understanding is most cell phones are afford ably made with rather small via holes, so clearly the problem is not diffic ult to handle.
I wonder how buried vias are plated? Does each board in the stackup have t o be plated before combining layers? So then the layers which can be route d by buried vias are limited to layers on the same core? Otherwise buried v ias would have to be drilled through the full stackup and plugged which rem oves most of the advantage of not blocking other layers.
-- Rick C. ++ Get 1,000 miles of free Supercharging ++ Tesla referral code - https://ts.la/richard11209
Sputtering is very useful, too. Say if you need to 'electroplate' an ant
- for example - to look at under an electron microscope, there's really no better method than sputtering.
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Pure nickel conducts electricity (and heat) about 1/4 as well as pure copper. I'd expect that plated metals will conduct less than pure samples, but nickel still loses. The base copper on a PCB isn't plated to it should be pretty good. The vias, not so good maybe.
Both thermal and electrical conductivity matter on many PCBs, and giving up 4:1 isn't appealing.
I'm thinking I could do this:
The idea is to solder paste a big pour so that when it's reflowed, the solder flows down to fill the vias, but the DPAK doesn't have vias to annoy production. A very skinny boundary of mask separates the DPAK part of the pour from the rest.
It would look weird.
Maybe most of the pour could be masked, but not the vias, so they get solder pasted to fill them up but the whole mess isn't covered with solder. Yeah, that would look better.
We normally don't solder mask our ENIG vias, but we don't paste them either.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Just tried an ENIG board and a supermagnet, no apparent attraction.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Thanks, I've always just wanted some magnetic material that's not iron. I was disappointed when I found my old nickles (a US five cent piece) weren't magnetic.
George H.
One advantage of nickel is that the surface oxide that forms is conductive. May not matter after the gold plating is applied, but model railroaders prefer it.
Yes, I'm sure you care a lot about how it looks. The solder is very heat conductive, so no reason to eliminate it.
-- Rick C. --- Get 1,000 miles of free Supercharging --- Tesla referral code - https://ts.la/richard11209
Sorry, what the model railroaders use is nickel silver, not nickel.
-- Rick C. --+ Get 1,000 miles of free Supercharging --+ Tesla referral code - https://ts.la/richard11209
When conduction is an issue, ie for high currents, we don't use silver. We use either supplementary flex or metal bar soldered in. Solder coating the track is also used sometimes.
NT
You want Canadian coinage, then. US 'nickel' is copper-nickel alloy. A Canadian dime sticks to a magnet (unless they've changed recently). Manganese bronze is another candidate.
Silver is nearly pointless. The conductivity is only a few percent better than copper, about 6%. When exactly would 6% make enough of a difference that it would justify the cost and the ready oxidation?
-- Rick C. -+- Get 1,000 miles of free Supercharging -+- Tesla referral code - https://ts.la/richard11209
It wasn't all that tight. They lost big time to the LibDems (Remain).
Boris the Animal now goes into the record books as the Prime Minister with the tightest ever working majority of just 1 vote and has suffered the quickest by-election defeat of any new PM since WWII.
That "majority" depends on giving another huge bung to the DUP too.
I am heartened to see that the Official Monster Raving Loony Party got more votes than UKIP (both lost their deposit).
Remainers will now be emboldened to poke Boris with sharp sticks until his government quite literally falls apart at the seams. Pretty much like the anti-EU Brexitators have done to every previous Tory leader.
Cameron's unwise gamble in 2016 has destroyed the Tory Party.
-- Regards, Martin Brown
Yes, but the opposition parties actually got their act together and didn't oppose each other.
Let's hope that is a sign of things to come.
Yes, but the Brexit party is the new UKIP party.
And the Labour party, with Corbyn's help. Labour was in
4th place (down 12%) behind the Brexit party, and narrowly avoided losing its deposit.Brexit/remain cuts across the standard political boundaries.
If the British empire was made on the playing fields of Rugby, the UK was unmade on the playing fields of Eton.
But, only NEARLY pointless; for metallization on ceramic, it was a winner (in its relatively small niche). Also for metallization on mica, in capacitors (though I never understood why aluminum or tin wasn't employed there).
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