[sdiy] Moving to Surface Mount - lots of questions

[John Luciani]

On Tue, Dec 6, 2011 at 6:19 AM, John Luciani <jluciani at gmail.com> wrote:
> On Tue, Dec 6, 2011 at 2:45 AM, Mike Beauchamp <mikebeauchamp at gmail.com> wrote:
>
>> Speed: Having never done it before, how much faster is it to
>> stencil-place-oven as opposed to insert-solder-clip?
>
> Stencils are faster if you are doing a few boards. Panelize your
> boards and screen them all at the same time. If you are only
> doing a couple of boards the setup time of the stencil probably
> doesn't make sense.
>
> If the majority of your parts are one side you could also use a hot plate.
> I use an a inductive hot-plate with a magnetic stainless-steel carrier.
> Place the panel on the carrier, place the carrier on the hot-plate,
> when the solder starts to reflow move the carrier from the hot-plate
> to a stone. I then manually solder the few components on the other
> side.
>
> If you are using leadless parts or parts with a bottom thermal pad
> it is a lot easier to use the stencil. However, for prototypes these
> can be done manually if you create special footprints.
>
>> 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?
>
> Except for parts that are leadless or have thermal pads repair is easier.
>
>> 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?
>
> I store these in stainless-steel and watchmaker tins. My storage ideas
> are at
> http://www.luciani.org/no-place-to-go/comp-storage/index.html
>
> I just discover some new storage containers made by LICEFA.
> I have started using these at work.
>
> See
> http://www.newark.com/licefa/diss-smd-box-n1-11-11-4-4/box-smd-16x12x15mm-b-l-yellow/dp/34M5631
> http://www.newark.com/licefa/a1-3-smd/cabinet-storage-smd-6drawer-esd/dp/34M5167
>
> My tools recommendations are at
> http://www.luciani.org/getting-it-done/assembly-hints/assembly-hints-index.html#smd-hints
>
>
>> Toxicity: Soldering irritates my asthma, although my fume extractor
>> helps heaps. Does sticking solder paste into an oven cause similar
>> fumes?
>
> Same fumes so you need to vent.
>
> --
> http://www.wiblocks.com



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