gEDA-user: 0805 geometry, was: Script for converting mm to hundredths of thou

[Armin Faltl <armin.faltl@xxxxxx>]

Obviousely 'Element [...' forces use of '[' in the pads etc. as
I got "syntax error on line 4" before I noticed the difference
in the element line.
Last I used your element line and 'Pad[...' as I had rewritten
before and now it works as intended, the only difference being
the hex-flags as opposed to text "square".

One thing I'd like to know is the exact meaning of "clearance"
in a pad - does this get added to thicknes or is it measured from
the center line of the pad, same with mask.


Below is what I think a comprimise reflow/hand-solder landpattern
for a smd-0805 should really look like, as opposed to the library;
the very reason I started my own 0805:

Element[ "" "SMD 0805" "" "smd0805" 0 0  0 0  0 100 ""]
(
#   Pad[x1, y1, x2, y2, thickness, clearance, mask, name , pad number, 
flags]
   Pad[ 950um  300um   950um -300um  900um 400um 1000um "1" "1" 0x00000100]
   Pad[3050um  300um  3050um -300um  900um 400um 1000um "2" "2" 0x00000100]
)

The geometry is based on dimensions for a SUSUMU RG series precsision 
resistor.
The pads are kept as separated as possible still covering the end-caps of
the part which allowes routing of 2 300um-traces with 200um separation
and should minimize heating of the part during soldering.
Laterally the copper is 250um wider than nominal dimension giving +25um on
each side for the maximum upper tolerance and +125um for nominal width.
Axially each pad is extending by 500um to provide a position for the iron.

If you disagree with this reasoning/geometry, please hint me why ;-)

Thanks for your help, Armin





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