Homebrew PCBs

----- Original Message ----- 
From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, April 07, 2006 10:34 AM
Subject: Re: [Homebrew_PCBs] Photo-etch PCB with DF12 connector


> My worry with that would not so much be the spacing, that should be fine,
> but i would be afraid the socket would come off if pulled on ;-)
> 0.4mm should still be possible with TT, that's just under 8/8mil rules i
> think. The problem is with those metric spacings the printer must "round"
> to the next full pixel, and i have found it is required to make the pads
> rather narrower than the spaces, to avoid problems.

Those DF12 sockets are made with metal tabs, but those are the only ones 
stocked by my modem supplier. There is a general shortage of those Hirose 
connectors, especially the ones with tabs, in the UK. Probably something to 
do with ROHS.

>
> BTW those throughhole pads in places seem VERY small with that size of
> hole in them, compared to the trace the rings are tiny. I don't think that
> is such a good thing with non-PTH boards.

They are the standard PTH size I use, I keep meaning to change them. I use 
thin wire for the links and don't have problems. I should have added 
teardrops which would help.

>
> Also, i notice you cross-hatched the ground plane. Why?

I didn't want to waste ink and solid areas seem to smear sometimes. They 
also take a long time to dry.

I'm just about to get my microscope out and start assembling that connector.

Leon
--
Leon Heller, G1HSM
leon.heller@...
http://www.geocities.com/leon_heller 

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