I’m trying to submit a four-layer board, and I’ve run into a couple of problems.
The first is that the top layer is showing up differently from the rest, and it is making the board size huge - it should be an 8 square in board, but instead is being shown as a 25 square in board. The layers all look fine in the viewer. As a note, I’m using Altium Summer 09, and viewing the Gerber layers in Camtastic.
I get the impression four layer boards are rare, but is there a way I can get these through?
Thanks!
[edit] The board is now passing DRC, but is still showing up as being way too large. Interestingly, the composite drawing in the order form is correct - but the square area is wrong. The board is supposed to be 3.635"x2.2", but is showing up as practically 5"x5"
[edit2] I tried adding the board outline to the top silk layer, and as a separate mechanical layer, but I’m still not getting the right board outline or area.
Do you have any component silkscreen (like overhanging connectors) outside the board edge? The batchPCB robot will include that when it computes the board area.
No. I fixed the overlap on an over-hanging RJ-45 connector in the first go-around by editing the component symbol. The final silk screen truncates at the board edge. The only place where something overlaps is on the mechanical layer, but that didn’t get submitted.
Also, it would have only added a half-inch to one end of the board. I get the impression that 25 square inches is some sort of default.
It seems the problem stems from the board layout not being centered at 0,0 - I moved the board to the origin, and it started giving me closer to accurate sizing information. It’s now only off by a few mils.
Also, it appears the bot totally ignored the outline layer for sizing.
I tried an board shape layer (corresponds to a surface rather than an outline) I thought it might be preferable to an outline because there there is no outer thickness to cause potential ambiguity. This resulted in the BOT thinking my board was bigger than I intended.
I was successful getting good sizing with an outline shape in the top copper that was 0.000 thick. The DRC did not complain. This included two designs that had some radiused corners.
I guess on my next order, I might put the outline layer in the silk layer. I think would still make it 0.000 thick. On the other hand, the top copper method worked very well.