Out-of-tolerance zero ohm resistors - Page 3

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Re: Out-of-tolerance zero ohm resistors

eroUno:
Quoted text here. Click to load it
rs with
matter.
.3W
2.5
y 1mV
ent, and
h a
MT-Jumper/product_id/14040
Quoted text here. Click to load it
  
Quoted text here. Click to load it
ection
with
and
rements
uminum
oard.)
Quoted text here. Click to load it
ghly)
Quoted text here. Click to load it

the gold layer is extremely thin, less than 1um and it is added after
the solder mask so it'll only be on pads

-Lasse

Re: Out-of-tolerance zero ohm resistors
On Sunday, May 31, 2015 at 2:06:35 PM UTC-4, Lasse Langwadt Christensen wro
te:

umeroUno:
Quoted text here. Click to load it
tors with
s matter.
 1.3W
Quoted text here. Click to load it
e 2.5
nly 1mV
rcent, and
ith a
od
-SMT-Jumper/product_id/14040
Quoted text here. Click to load it
th  
Quoted text here. Click to load it
-section
Quoted text here. Click to load it
d with
,
, and
surements
aluminum
 board.)
Quoted text here. Click to load it
oughly)
Quoted text here. Click to load it

Yes, but if you stacked a million of them you've have a stack of gold nearl
y
one meter thick!

Cheers!
James

Re: Out-of-tolerance zero ohm resistors
On Sun, 31 May 2015 11:51:05 -0700 (PDT), snipped-for-privacy@yahoo.com
wrote:

Quoted text here. Click to load it

Quoted text here. Click to load it
I think they'd be more like a mile thick.  ;-)

Re: Out-of-tolerance zero ohm resistors
Quoted text here. Click to load it

Quoted text here. Click to load it

for 0.062" boards said stack would be nearly a mile high,


--  
umop apisdn


Re: Out-of-tolerance zero ohm resistors
On Sunday, May 31, 2015 at 6:30:56 PM UTC-4, Jasen Betts wrote:
Quoted text here. Click to load it
 wrote:

erNumeroUno:
Quoted text here. Click to load it

).
Quoted text here. Click to load it
er,
z
early

Yes, 0.979 miles, but you'd own a goldmine!

Cheers,
James Arthur

Re: Out-of-tolerance zero ohm resistors
On Sun, 31 May 2015 15:56:52 -0700 (PDT), snipped-for-privacy@yahoo.com Gave
us:
snip
Quoted text here. Click to load it

  You'd be better off re-processing the tailings of an old abandoned
mine.

Re: Out-of-tolerance zero ohm resistors
Quoted text here. Click to load it

Quoted text here. Click to load it

I'd take the copper!

--  
umop apisdn


Re: Out-of-tolerance zero ohm resistors

snip
Quoted text here. Click to load it

  One can get 16 layers into 0.062 these days.  count again.

Re: Out-of-tolerance zero ohm resistors
On Sunday, May 31, 2015 at 11:33:04 PM UTC-4, DecadentLinuxUserNumeroUno wrote:
Quoted text here. Click to load it

Golden inner layers too?

Strictly, the stack is only half a mile high, since there's gold top and
bottom.  Problem solved.

Cheers,
James Arthur

Re: Out-of-tolerance zero ohm resistors
On Sun, 31 May 2015 20:54:11 -0700 (PDT), snipped-for-privacy@yahoo.com Gave
us:

Quoted text here. Click to load it

Actually, he (you) was referring to stacking *only* the gold layers, and
that stack would end up as one meter in thickness, no matter what
direction it faced.

  But certain charged particles would pass through all of them, and
occasionally, one would strike a nucleus and get deflected from its
original path.  ;-)

http://chemed.chem.purdue.edu/genchem/history/gold.html

  A million chances with each one... (particle)

Re: Out-of-tolerance zero ohm resistors
Quoted text here. Click to load it

half a mile high then, at most two of the layers will be plated,  

--  
umop apisdn


Re: Out-of-tolerance zero ohm resistors
On Sun, 31 May 2015 13:50:05 -0400, DecadentLinuxUserNumeroUno

Quoted text here. Click to load it

Anything that thick will really limit you on the components used.

Quoted text here. Click to load it

Not true.  Gold flashing is fairly rare.  Its only purpose would be
storage.  Don't do that.

Quoted text here. Click to load it

"Rivulet"? I've heard of wave soldering but liquid PCBs? Perhaps you
mean "rivets"?

Re: Out-of-tolerance zero ohm resistors

Quoted text here. Click to load it

Gold over nickel is super planar, which is great for BGAs. And it's
the best surface for lead-free solder. Solder practically leaps onto
gold plate. That's all we buy now.

I prototype on gold-plated FR4, too. It doesn't tarnish like copper.

https://dl.dropboxusercontent.com/u/53724080/Protos/Gold_FR4.JPG

https://dl.dropboxusercontent.com/u/53724080/Protos/Z338_PCB.JPG




--  

John Larkin         Highland Technology, Inc
picosecond timing   laser drivers and controllers

We've slightly trimmed the long signature. Click to see the full one.
Re: Out-of-tolerance zero ohm resistors
On Sun, 31 May 2015 15:18:12 -0700, John Larkin

Quoted text here. Click to load it

It may be easier for low production runs where you don't have the
temperature profiles set perfectly and on rarely run products but
there is no reason for it in mass production. It only adds cost.  I
was objecting to his "most modern digital" statement.  

Quoted text here. Click to load it

That's the "storage" point above.

Re: Out-of-tolerance zero ohm resistors

Quoted text here. Click to load it

We have a full auto P&P line, 7 zone oven with nitrogen, and do some
batches in the hundreds. My production people want gold.


--  

John Larkin         Highland Technology, Inc
picosecond timing   laser drivers and controllers

We've slightly trimmed the long signature. Click to see the full one.
Re: Out-of-tolerance zero ohm resistors
On Sun, 31 May 2015 18:52:32 -0700, John Larkin

Quoted text here. Click to load it

Because they don't have the line set up properly.  It's probably
cheaper to use the gold than to do the job properly anyway.

Re: Out-of-tolerance zero ohm resistors

Quoted text here. Click to load it
snip

  It is a modern world, child.  GOLD IS the "proper way", dufus.

  Even my motherboards use it, and now you are going to tell me it costs
so much more?  If it did, they would not be doing it.

Re: Out-of-tolerance zero ohm resistors
On Mon, 01 Jun 2015 12:55:51 -0400, DecadentLinuxUserNumeroUno

Quoted text here. Click to load it

But you're AlwaysWrong.  This is no exception.

Re: Out-of-tolerance zero ohm resistors

Quoted text here. Click to load it


  Motherboards are gold from top of the line makers.  You claim
otherwise?  You're an idiot.

Re: Out-of-tolerance zero ohm resistors

Quoted text here. Click to load it

The line was designed and set up by experts. And it's operated by
experts. We prefer a few microinches of flat gold than some random
number of mils of bumpy, crufty, tarnished ROHS solder.

750 pin BGAs, and lots of other things, solder better to planar, gold
pads.



--  

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement  

We've slightly trimmed the long signature. Click to see the full one.

Site Timeline