Homebrew PCBs

On Mon, Jul 19, 2010 at 11:56:48AM -0000, ae5ew wrote:
> Ok. I admit I'm ignorant when it comes to this subject. How is an IC 
> lead connected to say layer 8 on a 16 layer PCB. 

Via a via :-)

I presume you're talking about through hole components, in which case 
the via that forms the hole the IC pin goes through. For SMD, a via must 
be drilled.

On a commercially made board this via is through plated and makes 
contact with the tracks in the inner layer that you have connected to 
it. Some brave souls homebrew 4 layer boards, there are various 
strategies for making contact to inner layers in absence of through hole 
plating (I presume the hole on the top layer is a little larger so that 
a wire can be soldered to both the inner layer and outer layer to make 
the connection).

For me a multi layer board normally means fine pitch SMD (already 
increases the difficulty level in home making a PCB) as well as multi 
layers, so I just use a commercial board house since two lots of 
difficult tasks goes from being a fun challenge to frustration! (If push 
came to shove, I'd consider a 4 layer board where the inner layers were 
power and ground planes).