Dear Technet,

I hv an issue with a 4-layers boards. I am not sure what my customer's
requirement, because I am not familar with PCB fabrication. Pls escuse me. 
>From the fab diagram, this is one of the drawing what being showed.


        Customer's Requirement:            ______________
                                                0.4
                                           --------------
                                           |    0.6     |
                                           -------------- 
                                                0.4
                                           --------------


        PCB supplier's recommendation:     ______________
                                               0.11 x 2
--------------
                                           |    1.0     |
                                           --------------
                                               0.11 x 2
                                           --------------

Could anybody can explain to me what it means ? And what the differecnce
between the cust's requirement & the supplier's recommendation in term of
board processing and also when come to PCB assembly.

And could anybody tell me how to determine the PCB inner & external copper
thickness. I realise some of our boards, of same model, but differ in 
weight & thickness, and sometimes twist after reflow from batch to batch.

Thks and Regards..           

Poh Kong Hui 
Nera Electronics
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