The IPC-D-325 Documentation Requirements for Printed Boards, Assemblies and
Support Drawings, covers the minimum note requirements and how to read them.
In addition, the IPC-D-275, Design Standard for Rigid Printed Boards and
Printed Board Assemblies, also provides the minimum requirements, and how to
interpret them, for the master drawing.

At 02:17 PM 6/4/96 +0800, Poh Kong Hui wrote:
>Dear Technet,
>
>I am having big interpretation problem on the FAB drawing:-
>
>Customer's Requirement :-
>
>__________
>|        |      preprag 0.6 mm
>----------
>__________
>|        |      C.L.L 0.4mm
>----------
>__________
>|        |      preprag 0.6 mm
>----------
>
>It stated on the drawing as:
>a.      Thickness of copper foil is 35u 
>b.      Thickness of PCB thickness is 1.5/1.6 mm
>
>
>
>We end up getting an overall thickness of 1.7 to 1.77mm from our PCB supplier.
>
>The PCB supplier come back with their side of the story, 
>Supplier's interpretation is
>
>----------                    -----   
>|       |       35 u            ^
>---------                       |      
>                                |
>|-------|                       |
>|       |       70 u            |       
>|-------|                       |
>|       |                     overall thickness = 1.81 mm  
>|       |                       |
>|-------|                       |
>|       |       70 u            |
>|-------|                       |
>                                |
>---------                       |
>|       |       35 u            v
>---------                     -----
> 
>
>I would like to know whether the PCB supplier is right ?, and whar is the
>correct way
>to interpret the drawing.
>
>and also does anyone know of any spec/book that tell one how to interpret a FAB
>drawing ..
>
>I'm appreaciate for any comment given .. Thanks.
>
>
Regards,

Gary Ferrari
Tech Circuits
(203)269-3311
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