How to order boards with 70 um thick copper?

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The thickness of the copper depends on the oz. Currently Seeed can do 1, 2, 3 oz. Thanks.

70 um would be 2 oz copper.

Please check Fusion Premium PCB service.
seeedstudio.com/service/inde … PremiumPcb

For Fusion PCB contains 1oz copper thickness, but the board manufactured with copper thickness 18um - 0.5oz. Why?
I measured the copper thickness of the boards, received by order number 114233.

May I ask how you measure the thickness?
Would you please show us pictures? We will check with our Fab and feedback you.

As we check with Fab, your order 114233 can’t be 0.5oz.

The original FR4 board is 0.5oz. After the process like Chemical Deposition, Electroplating, solder mask, etc, the board will be 1 oz.

May I ask how you measure the copper thickness of order 114233.

First measurement location - without copper on both sides:

Second measurement location - with copper on both sides:

Subtract the first measurement from the second measurement and obtain a thickness of copper on both sides. 1.604-1.563 =0.041mm. Divide this value by 2 and obtain the thickness of copper. Turned 0.0205mm ~ 20um or 0.5oz

Use Digital Multimeter to measure Copper thickness… it is not convincible and has inaccuracy.

It have to be measured by professional machine to see the copper thickness, like the attached picture shows.

For 1.6mm 2 layer board, the orginal material is already 1.5mm , and has 0.5oz each side. Then we will go through all the process including laying copper. The outcome copper of the board will be really near 1oz each side.

You can use machine to measure the copper thickness. Or ship one of your board to us. We can test it and show you the specific copper thickness. Thanks.

I showed you the actual measured thickness of copper, admit that there is measurement accuracy up to 0.005mm. But actually I’m interested in the original thickness of the copper before the technical processes. If I order production boards with 2oz copper thickness, it is expected that this means the original thickness of the copper - 2oz. Thank you.

The actual thickness cannot be measure by Caliper, but have to tested by the professional Copper Thickness Tester. You can ask any PCB Fab in the world to see if your measurement is correct.
If you order a 2oz board, the original copper will be 1-1.5oz, and start processing. The outcome will be 2oz.
If you want the original copper 2oz, the outcome will be 2.5-3oz after processing. Thanks.

What is the thickness of the copper must be specified in the order Fusion Premium PCB to the original thickness of the copper was 2oz?

If you want the original copper 2oz, the outcome will be 3oz after processing for Premium PCB service.
We need to confirm the measurement by caliper is not correct, in case after the boards finish processing and get a complain for less copper. Thanks.

This means that I have to choose in the order form - 3oz, to was used FR-4 70um. Thank you.

hi!

i have a similar question

i need to design a resistor on a pcb and therefore i need to know exactly the resistance of the conductive material

can i guess it’s pure copper and it is 35 um thick?

thanks

The thickness of the copper depends on the oz. Currently Seeed can do 1, 2, 3 oz. Thanks.