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Re: gEDA-user: OT: I hate footprints



Well, there is a fair amount of standardization. Far from perfect but
some exits. Devices which use JEDEC packages seem pretty good, few
exceptions where you have to watch out for pin number. But JEDEC doesn't
cover every available package.

I have been working on a spread sheet where I try to capture all of
this. My spread sheet is available upon request.

Steve Meier


On Thu, 2008-07-31 at 18:29 +0200, Philipp Klaus Krause wrote:
> It seems the only way to deal with them is to create each footprint from
> scratch eachtime I have to use one. Nearly eachtime I try to use an
> existing footprint things turn out wrong.
> There seems to be nearly no standardization in these things. Each chip
> manufacturer gives them a different name, pcb uses yet another one (if a
> footprint exits). Different manufacturers call different sizes by the
> same name. You never know how wide something calles SOP really is etc.
> So for my latest board I needed something called TSOP-28 in the
> datasheet. I found something by the same name in pcb. I carefully
> checked dimensions. They matched. I created a geda symbol. Today I got
> the chips and started soldering. Then I noticed something seemed wrong.
> The manufacturer had used a different pin numbering.
> 
> Why can't manufacturers just provide footprint and symbol in some
> standard format that all programs could import? I feel like I spend a
> large part of the time it takes to design a pcb drawing symbols,
> footprints, etc.
> 
> Philipp
> 
> 
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