Homebrew PCBs

----- Original Message ----- 
From: "Adam Seychell" <a_seychell@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, July 26, 2009 4:06 AM
Subject: [Homebrew_PCBs] smallest practical SMD for homebrew ?


> Following the recent posts on BGAs, I'm curious what people consider the
> lower size limit for SMD to when doing home brew PCBs and projects. I
> used to use 0805 but found soldering 0603 parts wasn't that much more
> difficult, and so its my preferred choice for a new project. I
> experimenting with some 0402 on scrap motherboards and found it way to
> tedious to be practical. A big problem I see with 0402 is an inability
> to run a trace between pads.
>
> I found the no-lead chip scale packages (QFN) are somewhat more
> difficult to solder than corresponding leaded TQFP of the same pin
> pitch. Without reflow soldering, the pins of a QFN rely in wicking of
> solder applied from soldering iron tip located on the pad just external
> to the package. Its difficult to know if solder as wicked between pad
> and pin.

I don't find 0603 to be difficult.

QFN isn't hard. I extend the pads a little for manual soldering, and 
drag-solder them.

Leon