[sdiy] OT: Linux pcb and SMT?

[Jay Schwichtenberg]

Colin & others,

That is sort of what I was seeing from the data sheets. Also the
manufacturing process (type of soldering) changes the size and layout of
pads too.

I got an updated version of pcb with a new library for most of the common
SMT stuff (603, 805, 1206, SOIC, SOT-23). I will have to add 4, 5 and 6 pin
SOT-3XX packages. That sounds like a weekend project. They had to change
pcbs' resolution from 0.001 to either 0.0001 or 0.00001 (can't remember) to
support SMT.

So little time, so many synths to build.
Thanks all.
Jay

> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Colin Hinz
> Sent: Wednesday, May 12, 2004 10:51 PM
> To: Synth-DIY
> Subject: Re: [sdiy] OT: Linux pcb and SMT?
>
>
> On Sun, 2 May 2004, Jay Schwichtenberg wrote:
>
> > Howdy,
> >
> > Does anyone out there know of a SMT library for pcb under Linux?
> >
> > Also does anyone know of where you can find the specs for various SMT
> > pads/packageing?
>
> It's always best to refer to the individual datasheets. There are
> *numerous* SMT packages out there which appear to be the same but
> are not quite compatible. This seems to be a problem with QFP's
> in particular.
>
> In theory, there are IPC component standards, but since few (if any?)
> of the IC datasheets make any reference to them, I'm not sure if
> there's any use in obtaining them (btw, the IPC standards cost a
> fair amount of money -- or at least they did a few years ago).
>
> The only "sure bets" are resistors and capacitors -- even a lowly
> SOT-23 transistor can be a source of layout trouble, as there
> seem to be at least two pin numbering schemes in existence.
>
> - Colin Hinz
>   Toronto, Canada
>
>