From: Bob Blick <bobblick@outlook.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Mon, 22 Feb 2021 19:48:20 -0800
Subject: Re: [EE] Measuring PCB copper weight?
Thread-Topic: [EE] Measuring PCB copper weight?
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I bet the free ballpoint pen more than made up for the error :-(

Thanks for the heads-up, I've had non-critical hobby boards from them befor=
e.

Friendly regards, Bob

________________________________________
From: piclist-bounces@mit.edu <piclist-bounces@mit.edu> on behalf of Jesse =
Lackey
Sent: Monday, February 22, 2021 6:26 PM
To: Microcontroller discussion list - Public.
Subject: Re: [EE] Measuring PCB copper weight?

Just a minor LOL/Sigh, I got some boards made at JLCPcb, they have trace
antennas for RFID, a 55mm spiral square of 6mil wide track.  I was
having problems not seen on a proto pcb made in the USA.  After some
head scratching and fiddling and calculating, the trace antenna is 380
inches long, and with 1 Oz copper it measured close to 30 Ohms, as
expected, on the proto.  The pcb from JLCPcb is 44 Ohms, i.e. 30% less
copper than the standard for 1 Oz.

Never seen that before.

Now they want me to measure the thickness.  Ya right.

J

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