On Fri, 25 May 2018 22:56:58 +0100, Paul wrote:

Jimmy Wilkinson Knife wrote:
On Fri, 25 May 2018 19:29:44 +0100, Paul wrote:

Jimmy Wilkinson Knife wrote:

It amazes me how they can get that much current into it with little
motherboard tracks - if you consider how thick a cable is to supply your
electric shower or cooker for example, with a third as much current.

The board is multi-layer, and inner layers can be used to route power.

Yes, you do need "planes" to handle that much current. In some
cases (Gigabyte), they even use 2oz copper for that, rather than
the "normal" half ounce copper. Sometimes you see mention of
that in some advertising blurb.

Why on earth are they using such an antiquated measurement? It should
be measured as 0.07mm.

Because discussions with the PCB shop, don't work the way
you think. It's more like a discussion with a chef in
a kitchen, than with a machinist in a machine shop.
Every profession has its own way of doing things.

My policy is "we don't argue with success". If the
methodology produces good results, who am I to argue
with petty details :-)

I can understand old measurements with a bricklayer, but people manufacturing the latest technology I'd expect to use metric measurements.

The measurement that really annoys me is "mills". Some people think it means thousandths of an inch, some think it means millimetres.

--
History teaches us that no other cause has brought more death than the word of god. -- Giulian Buzila