[sdiy] Cheap microscope for SMD

[Jason Tribbeck]

> From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
> bounces at dropmix.xs4all.nl] On Behalf Of Joe Grisso
> Sent: 18 February 2010 05:39
>
> Nah, cheapest of all is soldering a 0.5mm pitch 100-pin QFP without
> magnification.

I've not needed magnification for my 0.5mm stuff - this was done without:

http://www.tribbeck.com/electronics/xilmezzie/DSC00384s.JPG

Okay, the two voltage regulators (lower right hand side) are slight skewed...

> Granted, I did have a headache for the rest of the day... so maybe I
> should factor the cost of acetominaphen into that.

Didn't have that either.

> Honestly though, 99% of the fine-pitch soldering stuff I do is > 1.0mm
> pitch, and I've been happy using a photographer's loupe on that stuff.
> I've found that the three biggest factors in high-precision SMT work
> are:
> 
> 1) solder mask on PCB. *I can't stress this enough*

I also didn't have any solder mask - I etched the board myself, and I've not got into solder resist yet.

> 2) Flux. Flux. Flux. I started using a flux pen. It wasn't enough. Get
> liquid flux and a needle bottle. Use liberally.

I did have plenty of flux (from a needle bottle) - and I would agree that it is essential.

And desolder braid - just in case :)

> 3) The right tip for the right job. Since I'm a Metcal advocate

I've no idea what my tip is, but I think it's about 1.5mm wide. It certainly did 2/3 pins at the same time.

> Even though I've been VERY frugal and masochistic in my soldering
> lately, I still yearn for a proper trinocular scope, fiber ring light
> and double-bar boom stand with clutched X-Y table. *swoon* Someday...

Maybe when my eyesight starts to fail.

I did acquire a magnifying glass from work a couple of weeks ago (I've not used it there for about 8 years) - but that was only to aid visual inspection of finished solder, rather than doing the soldering itself.
-- 
Jason Tribbeck