On 2013-04-16, at 10:04 PM, lee@baudalign.com wrote:

> Possibly a stupid question, but can a HASL finish be used _by itself_ to
> reflow fine-pitch components?  I have a board that needs an accelerometer
> soldered, and my DIY attempts at a stencil aren't getting fine enough
> results; is there enough solder on a HASL finish to attach tiny chips
> with?
> Or are there any tricks that someone can impart?  I don't want to shell
> out for a laser-cut stencil yet as it's very much a prototype.

It's not a stupid question at all.

Theoretically? Yes. But then there's also the conundrum that any HASL finis=
h that leaves enough solder to re-wet and bond is probably a horrible surfa=
ce for fine-pitched SMDs ;) At best, you'd probably have a very dry and unr=
eliable joint, if at all.

I've given up on HASL even for prototypes. In fact, especially for prototyp=
es -- ENIG is so much better for hand assembling SMD and is very reasonably=
 priced where I get my boards made*.

-m

* www.oshpark.com -- just a happy customer


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