Q: What files and documents do you request for my PCBA orders?
We need Gerber files, Centroid data and BOM for your PCBA orders. As have already placed your PCB order with us, actually you only need to send the latter two if your PCB Gerber files have included the layers of silkscreen, copper track and solder paste. If your PCB Gerber files are missing any of the above-mentioned three layers, please resend them, as this is the minimum request for PCBA. For the best possible result, please also send assembly drawings, instructions and photos to us to avoid any ambiguous and even mistaken placement of parts, though these are not required by most of the assemblers.

Q:  What is Centroid?
Centroid is the special file for assembly used for quickly programming the assembly machines. This is also known as aka Insertion, Pick-N-Place, or XY Data. Some of the CAD tools will automatically generate this file and some not, but you may need to modify the file and then generate the Centroid file. The Centroid file describes the position and orientation of all the surface mount parts, which includes the reference designator, X and Y position, rotation and side of Board (Top or Bottom). Only surface mounting parts are listed in the Centroid.