Friday, September 21, 2018

Completing board Exporting Gerber Files:

Gerber files are the graphic files used to manufacture a circuit board. Below is my completed circuit board in Eagle. I have run DRC and fixed all errors.  I have added a GND polygon on top and bottom layers. I have cleaned up the text by smashing the components and moving/sizing or deleting text.

Ready to export  Gerbers

The PCBway web page walks you through the process of ordering.  In an effort to save money I have kept all options vanilla or default except that I have needed to select 5 mil/5mil width/spacing wires.  I could nit use 6mil wires to wire the BGA so it had to be done

I have used the Eagle design statistics to generate the size in the PCBway GUI.

The cost of 5 boards is 35 dollars US.  I needed a top stencil as well with the added cost of 15 dollars.  I should be able to reuse this stencil with additional versions of the board assuming that I do not move the BGA and FPGA components on the board.

Below is the CAM processor options. It is very intuitive. You simple select the layers that go into each gerber file.  In my case since this experimental board is only 2 layers, I have deleted intermediate layers 2 and 15. I have also added t_value to top silkscreen.  I have generated the gerber files and gziped them into a folder.  The PCBway GUI takes the zipped folder as input. My first attempt failed since the board house needs RS-274X files.  I have loaded the local CAM RS-247X file and re generated the files.

see below:

So now I just wait for the board house to get back to me.

09/29/18 Note:  PCBway has reviewed the Gerber files and approved the design.  They gave a revised quote. It seems that the Boards will be 105 dollars US since I could not keep wires outside a 0.2mm exclusion area from CBGA balls.  The minimum size for CBGA ball is 0.3mm and the balls have a  0.8mm spacing. So 0.8mm minus 2 times 0.2mm exclusion minus 0.3 mm ball diameter = 1mm.  This is the remaining width for a wire travelling in between CBGAs. Unfortunately a 5mil wire is 0.127 mm wide ( 0.005 inch times 25.5 mm/in) so it can not be done.  And because of this the board manufacturer must use advanced techniques to layout the CBGA. Therefore the quote went up.

Your comments are welcome.