Homebrew PCBs

----- Original Message ----- 
From: "Dave Hylands" <dhylands@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, June 16, 2004 5:33 AM
Subject: RE: [Homebrew_PCBs] How does everyone hold down SMT parts


> Hi Martin,
>
> This is what I do. I've never had any formal training, so my technique
> might not be the best, in which case, I'm sure that one of the more
> knowledgeable members will correct me :)
>
> I use liquid flux. I paint the pads with it. It's slightly tacky. If
> that's not enough, then I use a pair of tweezers to apply pressure from
> the top and use a very small amount of solder on the tip of the iron.
> This is typically good enough for tacking purposes. You're supposed to
> heat the part and apply the solder to the part, rather than putting the
> solder on the tip, but with one hand holding the tweezers and one hald
> holding the soldering iron, there's no hands to hold the solder.
>
> Once the part is tacked down and everything lines up properly, I
> properly solder the remaining pins, and then come back and redo the
> original tack.
>
> You can get liquid flux in a pen from Digikey. I also got a bottle from
> my local electronics supplier.

That's how I do it, as well. I use a stereo microscope for devices with
really fine pitch leads, like 0.5 mm QFP parts.

Leon