Hi,
I created a library for a TQFP-128 fine pitch part with 0,4mm pitch size.
For this reason in the library package I used a 0,4mm grid as well.
In my project's layout, where I want to use that part, I also have a
0,4mm grid size so that it works together with the package I created.
However, if I place the part on the PCB layout multiple times, not all
parts are aligned to the 0,4mm layout grid.
Since both the layout grid size as well as the package grid size in the
library are 0,4mm, this should not happen, right ?
Since it is a little hard to explain I uploaded a picture here:
http://img404.imageshack.us/img404/1152/misaligned04mmpitchcomp.png
Unfortunately in the picture one can't see the 0,4mm grid.
However, while the upper left chip package is perfectly aligned to the
grid, the other three packages are not.
I tried to place them in a way that all chip pins are perfectly aligned
to each other, but as you can see this was not possible.
A dirty solution would be to switch to a smaller grid size in the layout
(e.g. 0,1mm).
However, I would prefer to use the bigger 0,4mm grid so that layout
design is easier to work with.
Is this a bug in eagle ?
I'm using Eagle 5.6.0 Light.
sincerely,
stefan