Let's do the math for a raspberry pi sized board:

Dimensions: 85 mm x 56 mm

Area: 4760 mm^2 or 7.38 in^2

Copper: 4 x 1oz layers

Copper Weight: 0.205 oz = 0.013lb

Copper price: 0.013 * $4.50/lb = $0.0585

And that doesn't include the copper removed by etching. So if they paid a 6c tariff on each raspberry pi board, they'd be overpaying.

Can they generate a certificate claiming each board contains no more than this amount of copper, overpay the tariff by a few pennies, and carry on?

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thisisit 2 days ago | parent | next [-]

Repeating my comment. That is not how this works.

Governments ask for something like a metal spectrometer analysis of components. They might even say each batch needs to be analyzed and we trust analysis from spectrometers manufactured and/or operated in US. Each condition raising the price for certificate/analysis even more.

Or directly from the post

> U.S. customs is demanding a Certificate of Analysis (which could cost thousands of dollars and to determine what exact amount of Aluminum, Copper and Steel are in the product), otherwise they assume the entire PCB consists of copper, aluminum, and steel, and charge a 100% tariff on the whole product.

	▲	tritipsocial 2 days ago \| parent \| next [-]
		I don't believe your claim that governments ask for something like a metal spectrometer analysis, especially since Digikey hasn't reported the same disruptions. There's no way Digikey did this for all 16.5 million parts. In later comments on their blog they admitted they didn't even file the paperwork and left it up to the customer, who obviously wouldn't know how, causing the part to get stuck in customs. It's a frustrating situation for them but there's no way CBP is making people break out lab equipment to import a PCB.
	▲	runako 2 days ago \| parent \| prev [-]
		Do they have to do this each time they change the composition of the board? What about if they just move/change the layout of the copper traces?

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crote 2 days ago | parent | prev | next [-]

Yes, that's how the math usually works with properly-functioning global trade.

Now prove that your math is correct. Can you hand over paperwork proving that it is indeed a 4-layer PCB and not a 32-layer one? Can you prove the 1oz copper isn't secretly 2oz? Can you prove it isn't a copper-core PCB? For all we know that PCB is a 1.6mm-thick solid chunk of copper!

And what about all the parts on it? Do the manufacturers of all the components on top of that PCB provide an exact per-element writeup? How many grams of copper are in that power inductor, or the ethernet jack's magnetics?

We're still not entirely convinced your paperwork checks out. Could you please have a testing lab run it through a mass spectrometer, just to remove any doubt?

Yes, we know it's a $1.50 board. No, we don't care. Yes, you really have to do it again for the next one-off shipment - you didn't go through the proper year-long type approval process, after all.

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TZubiri 2 days ago | parent | prev | next [-]

It was easiest to do some napkin math than throwing their hands in the air and writing a blog post.

I suspect this is more about politics than it is about international trade. If you've ever done imports you know that there's a substantial amount of paperwork and compliance, demanding that products state their composition doesn't seem extraordinary at all. Maybe OP should try consulting what regulations food exporters must follow.

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adgjlsfhk1 2 days ago | parent | prev [-]

only if they pay a few thousand dollars to certify that for every single board they sell.