On Sun, Aug 22, 1999 at 08:23:16PM -0400, Bob Drzyzgula wrote:
> Well, I drew out one adapter design, to see where we were
> in the ballpark.  I designed a simple 28-pin SOIC to DIP

OK, so thinking it through again, trying to
account for more costs...


Suppose that one figured that it would be possible to
sell 5000 28-pin SOIC-to-DIP adapters, in 500 sales
of ten per bag. Assume additionally that:

 * It will take two prototype runs of 30 units each
 to get it right, at a cost of $228 per run on a
 three-day turn, or $456.

 * A single production order for 5000 units would be
 made at a cost of $1600 plus $125 NRE. (this is at
 $0.32 each, the difference from the previous quote
 being in (a) the quantity and (b) Wet solder mask
 instead of LPI.)

 * Each board would be supplied with 30 pins (two
 to mess up), so 150,000 pins would need to be
 purchased. Using Digi-key's 5000-unit price for
 the pins I quoted before (ED5055-ND), this would
 cost $4725.0. At these volumes, the unit price
 may be significantly different.

 * Someone would of course have to bag these things,
 with a board and 30 pins. I don't know how much such
 services run (perhaps Don McKenzie knows), but
 I'll throw in a WAG of $0.25 per bag, or $1250
 total.

Adding this up, 5000 boards, each bagged with 30
pins, might have an aggregate cost of around $8156,
or $1.63 per kit, unless I've made some horrendous
arithmetic mistake. If you leave the pins as an
exercise for the customer, and forgo the bagging
cost, the core cost for the board would be around
$0.36 each. If one buys in batches of 1000, this
cost per board rises to $0.70 plus the amortized
cost of the prototypes.

Don't know what to make of this other than that
Wagner's guess that one could do this for around
a $1 per board may not be all that far off, as
long as one can find the cash to do a run of at
least 1000 or so, and can wait for a long
turnaround in production.

Now, there's a QFP-80 package (Hitachi H8S/2134:
square, 0.65mm pitch) I'd like to adapt into a
PGA for prototyping. I'll probably try to design
a board to do that, but then it gets to be a
real pain as far as I can tell, because one
then has to mix hard metric and inches on the
same board; I've not found this to be the easiest
thing to do in Eagle. Anyone done much of this?

--Bob

--
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Bob Drzyzgula                             It's not a problem
bob@drzyzgula.org                until something bad happens
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