Homebrew PCBs

Well, I just scanned the boards and posted the image in the files 
section -- PCB-Friday001.jpg.  Have a look, they turned out pretty 
darn good.

Don't be alarmed by the burn marks, let me explain what you are 
seeing.

After drilling all the holes, I printed out some transfers for the 
silk screen artwork and transferred them to the component side of 
the boards.  One of the boards in the image show this.  I then 
realized making a two sided board is going to be pretty tough, but I 
have a better idea of that now.

I then went about Derek's tinning process with the solder paste.  I 
have a number of butane powered torches so I thought I would give 
that a try, I wouldn't recommend it.  The heat is too focused and 
hard to control.  The heat gun, works much better, but you have to 
keep it moving or you get burns like you see in the photos.  The 
burns are not as bad as they look in the scan, I think the shiny tin 
sections threw off the brightness/contrast settings making it look 
worse than it really is.

The tinning again went pretty easy.  You can see that some areas are 
heavier than others and some areas could have used a tad more heat 
to get it to flow out.  I would wager to say that getting the 
lighting just right will greatly improve this part of the process.  
Seeing what is going on is kind of tough - there is some smoke, but 
not much.  While heating the solder paste, you can see it melt and 
turn shiny - this is part of the problem with seeing what is going 
on.  If you have a bright light on the far side and you are sort of 
looking towards it, it blinds you a bit (like looking at a bright 
light does).  

I believe I have even got everything mirror imaged and oriented 
correctly this time too.  However, while drilliing the holes I 
realized another error in my circuit - I forgot to put a resistor in 
for the power indicator LED.  You will see the repair as a large 
drilled hole "breaking a trace" and on either side two smaller holes 
to put in the resistor.

Well, I guess that's another lesson learned and another club to 
join :-)

If anyone has questions, feel free to ask, sooner rather than later 
as I know I will start forgetting everything I did :-(

Chris






--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing" 
<lcdpublishing@y...> wrote:
> Check it out! 
> 
> In the files section, look for heatguntoner001.jpg it's a scan of 
the 
> board after etching.  The scan does not show the glossy toner 
effect 
> from the heat gun. I looked at it with a loupe before etching and 
the 
> toner did look like it blended together pretty good (my eyes are 
not 
> the best, but it did look pretty good).  The etching again, went 
very 
> good.  Tomorrow I will wash off the toner to see what the copper 
looks 
> like but I suspect it is going to be pretty crisp looking.  Under 
the 
> loupe, it appears as though I should have etched for another 
minute, 
> but it is pretty darn good looking so far.
> 
> I don't want to remove the toner in case there is something wrong, 
> don't want another "IFU" to sleep on :-)
> 
> Chris