gEDA-user: footprint help please

[gene glick <carzrgr8@xxxxxxxxxxxxx>]

I have a part with no vendor recommended footprint.  It's called VSOP30
pin pitch = 0.22mm +/- 0.1
center-to-center = 0.65mm
outside-to-outside width = 7.6mm +/- 0.2mm
pin size is 0.45mm +/- 0.2mm

Here's the data sheet, see pg 30.

data sheet:
http://www.asahi-kasei.co.jp/akm/en/product/ak4390/ak4390_f03e.pdf

I don't know how to size the pads correctly.  Do the tolerances work as 
worst-case of one follows with the worst case of another - that is, if 
one spec is off to +max, then all tolerances will be off to the + max? 
Or is it mix and match, +max of this and -max(min) of that?

How much pad do you need on the outside of the pin, and how much on the 
inside assuming hand soldering?

I came up with this:
pad length = 2.1mm
outside-to-outside = 9.8mm
inside-to-inside = 5.6mm

Is that reasonable?  The pads look long to me.


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