[sdiy] Moving to Surface Mount - lots of questions

[Paul Maddox]

Mike,

> after assembling a few PCB's with a few hundred resistors, I've been
> thinking about moving to Surface Mount for my next project. Please
> convince me, or talk me out of it :)

bring it on, I love SMD..

> I've watched a few videos of people using stencils to apply solder
> paste, placing the components, and then oven-heating the boards. That
> looks like it would be pretty fast to assemble, but I do have some
> questions for the experts:

I wouldn't bother for low volumes (<10) it's a lot of messing around for one offs.


> Speed: Having never done it before, how much faster is it to
> stencil-place-oven as opposed to insert-solder-clip?

SMD soldering, with a waveflow tip, is a lot quicker for large pin number devices (44pin QFP for example).
For things like resistors, there's minimal difference.

> Reliability: I know that repairing a through-hole board is easier for
> most people, but is the reliability of SMT stuff on par with TH?

the reliability is, repairing is probably easier. One of the problems I have with TH is when it comes to desolder a 40pin chip it takes forever, heat pin, desolder, heat pin, desolder, etc, etc... with SMD got some solder wick, lay it across 20 pins, heat up, done..

> Storage: Those SMD resistors are tiny! What are some good ways to
> store 30-40 different values so they can easily be grabbed for
> populating?

My wife is into crafts, specifically beading.
So I nabbed some of her storage boxes, here's something not too dissimilar
http://www.spottedcanary.com/uploadedImages/Articles/Jewelry_and_Beading/JB_GO_ART3_Photo2(1).jpg

> Toxicity: Soldering irritates my asthma, although my fume extractor
> helps heaps. Does sticking solder paste into an oven cause similar
> fumes?

almost certainly.
I would say I find soldering with SMD less irritating than TH, but there's still some smell.

Best of luck.

Paul
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