We provide you some of the useful sites information from which you can download the documents relevant to the PCB Design.
Download and refer the IPC documents from the following website @ http://www.ipc.org/default.aspx
To know more signal integrity look @ http://www.sigcon.com/
Get documents about the footprint creation @ http://www.pcblibraries.com/
Information about the PCB fabrication @ http://www.pcdandf.com/cms/
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