Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Curtis Pope" <popecurtis@...> 
wrote:
>
> I just wanted to share my recent success and lessons learned.  I 
need
> to make my first PCB which takes a passive RFID reader IC and
> integrates it  with a PIC, MAX232 and several LEDs and required
> components.
> 
<snip> 
> 
> Drilling was pretty smooth, used a drywall screw and hammer to tap 
>an
> indention where the hole was to be drilled and a 1/32 drill bit to
> drill it out with my dremel.
>

It's even easier if Eagle has a print option to draw the pads with an 
open center. The exposed PCB material in the middle of the pad gives 
the drill an easy place to start. Many CAD packages have this option 
but I'm not sure if Eagle does.


> Assembly...here's where I learned lesson #3...double sided boards
> without through plating are a pain to solder.  I had to apply solder
> to the lead between the component and the pad, keep it hot and then
> push the component down to seat nicely.  I have now reworked my 
>design
> and put an extra VIA and small bottom side trace near the component 
>so
> i can just solder a wire (using cut off leads) through the board to
> pass the signal.
> 

I've always found it easier to install through-hole components before 
soldering and bend the leads over the pads on the bottom side of the 
board. Depending on the layout, many of the components will only 
require bottom-side soldering. Once the bottom side has been 
soldered, though, the top can be done if you need to.


Vias on non-plated boards can be done pretty easily by threading a 
length of stripped wire-wrap wire through all of the vias from one 
side of the board to the other. Once all of the vias have been 
threaded, they can then be soldered on both the top and bottom sides 
of the board. After soldering, you would trim the wires connecting 
them with an Exacto knife. (You may want to use a larger diameter 
wire or cut-off component leads for any tracks carrying significant 
current.)


Regards, Bob