V G wrote:
>> Uhm... still no mounting holes...
>
> It's not finished yet! I'll be sure to put appropriate mounting holes
> for M3 hex standoffs.

Adding holes is part of the placement process.  In other words, this is don=
e
before routing, not after.  It was a appropriate comment since you showed a
routed board.

> - Coil Power: 1200 mW
> - Nominal Voltage: 12Vdc
> - Coil Resistance: 120ohm

If that's all you need, you can use much smaller packages.  All you need is
a transistor that can withstand 12V and carry 100mA.  Just about anything
can do that.  Don't forget the diode to catch the coil kickback when turnin=
g
off the relay else whatever transistor you choose will get fried.

Something like a IRLML2502 should do nicely, but it doesn't need to be a
FET.  Especially considering your extreme cost sensitivity, you could use a
MMBT4401, emitter to ground, base to PIC pin with resistor in series.  Let'=
s
say you count on a minimum gain of 50.  That means you need a minimum of 2m=
A
base current.  To be pessimistic, let's say the B-E drop is 700mV.  That
leaves 2.6V accross the base resistor.  2.6V / 2mA =3D 1.3kOhms, so a 1kOhm
resistor sounds about right.  The combination of MMBT4401 and 1KOhm resisto=
r
will cost a small fraction of a suitable FET.


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