11 Apr
2013
11 Apr
'13
11:34 p.m.
On 4/11/2013 12:34 PM, John Wilson wrote:
On Thu, Apr 11, 2013 at 03:07:27PM -0400, David Riley
wrote:
My understanding was that they charged more by the hole than by size.
Also double sided if the layout was doable that way would make the board
order from a real board house way cheaper. Andrew's latest SCSI board
is $12 and area wise not that much less than these flip chip cards being
discussed. In the quantity that a mass buy for multiple builds of
straight 8's would scale to, I'd think the price would get pretty
reasonable.
I knew the fellow who did the card tabs here in Orange County, Stu
Phillips for MDB, Dilog and Emulex, but he died a few years ago, and I
think his company changed hands.
Otherwise I'd look him up and try to get his dies. The dies cost, the
runs and material don't. Helped that he knew some tool and die makers
who owed him to get into the business in the first place.
If anyone can trace the Stu Phillips, and you can point me at whoever
might still control it, I could ask about the dies, as I doubt they were
discarded.
Jim
I gave up ferric chloride etching in high school.
I couldn't get the
yields up high enough. I was always tempted to try the photoresist
presensitized stuff, but it was EXPENSIVE, so I never did.
I tried it a little and
had no luck getting consistent exposure.
The pens don't cover too well either (but they'll do in a pinch).
The Datak direct-etch dry transfers work *great* but it's a hell
of a lot of work for each board.
Haven't touched any of this in ages -- these days I'm a germ farmer
(septic tank). I'm not sure a gallon or two of FeCl3 would be enough to
sterilize it but there's no way I'm risking it just to save a few $$$
from oshpark.com (which kicks ass) or batchpcb.com (which used to until
they botched a web-site upgrade last September and still can't be bothered
to fix it). John Wilson
D Bit