> On Oct 11, 2015, at 12:53 AM, John Wilson <[email protected]> wrote:
>
> ... but I'd rather go RoHS.
I would recommend against that. Not unless you are trying to create a
commercial product where you *must* be RoHS to conform to the requirements of
the bureaucrats. Use real solder -- the job will be much easier and the result
more reliable. Real solder is still available, including solder paste.
I asked one of the technicians at work about this stuff a while ago -- they
know all about this question since they have to use RoHS when doing rework on
modern designs. And what I just said is what they told me (i.e., don't, unless
you are forced to). They also told me that real solder works just fine on
lead-free parts. I tried that and can confirm this is correct.
> ...
>> I was hoping for the Pick 'n' Paste machine to come along and save me from
>> having to do all that by hand but that project seems to have faded away.
>
> Oh seriously! I've been hoping one of the homebrew SMT assembly robot
> projects would "take" too, at a reasonable cost. Making prototypes is
> bad enough ... but what if I get it working and then I'd want to make
> dozens of these things, at 4+ hours each?
I would think a pick & place robot would be a fairly straightforward derivative
of a 3d printer. But is that really needed? Placing the parts isn't all that
terrible. The trouble is the soldering. I have read (and posted here in the
past) a nice article (in German) on the use of a toaster oven with some clever
temperature control as an IR reflow soldering machine. I haven't tried this
yet, but it sounds like a good scheme, and would allow the use of BGA parts at
least in moderate sizes.
At least one of the moderate cost small volume PCB fab shops will deliver
solder paste screens along with the finished boards if you ask for it.
paul
