On Mon, 20 Dec 2010 10:07:05 -0500, "Olin Lathrop" said:
> Kerry Wentworth wrote:
> > It really isn't that hard.  Print the artwork on to magazine paper
> > with a laser printer, transfer to copper clad using a laminator, and
> > etch.  I can reliably do .5mm spacing, which is as small as I can
> > comfortably do hand soldering.
>=20
> Note that's a whopping bit 20 mils.  Your not going to do a .65mm (26
> mil)
> pitch QFN package with that as the OP is trying to do.  He either needs
> to
> use a larger package or have the board professionally made.
>=20
> Maybe someone that's really really good with homemade PC boards can do
> this,
> but that's going to take some experience and experimenting at best.

It is doable, but painful. QFN is a horrible package to deal with at
home, especially if it's more than 20 pins and tight pitch. Getting heat
to flow under the chip with such thin traces is really hard.

Bob

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