This is how it looks underside:
http://picasaweb.google.com/funlw65/20100513#5535259872597475378

On Nov 2, 5:56 pm, mattschinkel <[email protected]> wrote:
> The actual parts are cheaper in SMD as well.
>
> Matt.
>
> On Nov 2, 5:27 am, Oliver Seitz <[email protected]> wrote:
>
> > > SMD versions would be cheaper to manufacturer.
>
> > That's true. I've once asked my PCB assembling company, and they told me 
> > how PCBs are populated:
>
> > 1. solder paste is applied to the top side for SMDs using a stencil
> > 2. top-side SMDs are placed in the paste
> > 3. top-side SMDs are soldered (infrared, hot-air or the like)
> > 4. bottom-side SMDs are glued in place without solder paste
> > 5. the glue is dried. This takes its time and therefore costs money
> > 6. top-side THTs are placed
> > 7. top-side THTs and bottom-side SMDs are soldered (possibly selective, 
> > wave soldering or the like)
> > 8. bottom-side THTs are placed and soldered by hand. That's expensive, of 
> > course.
>
> > So, cheapest is SMD with parts on one side only. Next is THT only. Then 
> > come mixed SMD and THT with all parts on one side. Then SMD on both sides 
> > plus THT on top side only. The most expensive are PCBs with SMD and THT, 
> > both on both sides.
>
> > I'm not sure where to put "SMDs on both sides, no THTs" as it could well be 
> > that no glue is necessary then.
>
> > All of this only applies to automatically populated PCBs in perhaps 100 
> > pieces or more. For low quantities, THT might even be cheaper as no 
> > solder-paste stencil has to be made.
>
> > Greets,
> > Kiste

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