Assembly Drawing - It’s not always possible to have all of the information needed for a successful PCB assembly printed on the blank PC board. Some smaller assemblies will have no reference designator silkscreen. This is most important to note when it comes to polarities. We have found that while CAD packages designate a two pin device as pin 1 and pin 2, there are no standards that define that one pin is always the cathode. What this means is that we can’t always rely 100% on the CAD/CAM import to determine apart polarity. Additionally a drawing can provide special notes, instructions or precautions for certain items and the best method to be installed, soldered and cleaned. LED orientations and markings is a good example of drawings providing visual aid to the assembler. If an assembly drawing is available, we encourage that it is provided.
Fabrication Drawing - This reference drawing is typically provided as part of the gerber file set. In the event the customer is consigning the bare board or the drawing is not provided in the gerber set, we request a fabrication drawing to provide an incoming review and revision verification.