What Design Data is Needed to Make a printed circuit board?

To actually build a printed circuit board the manufacturer needs quite a few pieces of data from the designer. I've summarized the data and its function below:

1.Gerber Files - these are actually "CNC" files which drive a photoplotter which creates the film used to expose each conductor layer in the board. There is also a Gerber file needed for other processes such as solder masks on top and bottom, paste masks and silk screens. So a four layer board could have 8-10 gerber files associated with it.

2.Drill Files - these are CNC files very similar to Gerber (but different) that are used to control a drilling machine. Plated through holes have to be drilled. On multi-layer boards you can have some holes that go all the way through, some that only go through a few layers and such. These each require a different drill file. There are lots of aggravations with drill data - first, there is no consistent standard as to how the drill tools should be defined in the header; second the coordinate system of the drill data can sometimes be offset from the Gerber files. Finally, one needs a separate document that describes which file passes through which conductor layers.

3.Routing Files - similar to drill files but defines a path for routing out the board.

4.stackup - the stackup is generally a print or written description of the board material, thickness, interposer and order. It is essential for multi-layer boards.

5.IPC-D-356 - esentially an electrical database of connections needed for testing the completed board. It is a very old format with a couple of variations and contains net names, test points and pins. Again, sometimes the data on this file is offset from the Gerbers which require manual intervention when trying to use this data.

6.Documentation - describes key elements of the board (i.e. locations), dimensions, materials and such. It can take the form of a PDF file, an HPGL file, Gerber file or AutoCAD file.

7.Component Placements - this is not used by the bare board manufacturer but is used for DRC checking and for generating pick and place files. The component "library" is located in the EDA directory (as data) and the component placements are in the layer section: comp_+_top for the components on the top side and comp_+_bot for the components on the bottom side.

To know more:

What is ODB++