On 3/18/2016 10:36 PM, 'Brad'
unclefalter@... [Homebrew_PCBs] wrote:
> <snip>
> I’m wondering – what differs in etching with double sided projects?
> And when they say the holes weren’t plated through, does it mean what
> I think it means (there would be a copper connection between a trace
> on one side through a hole the component is soldered into through to
> the other side?). Not sure I’m understanding how the connections
> would be made from one side to the other.
>
Hello--
One process used in the 1970s involved drilling holes through a
double-sided copperclad board, followed by an
electroplating process that deposited copper on the insides of the
holes. The board was then coated with resist,
exposed, developed and etched. Removal of the remaining resist exposed
the plated-through holes (vias)
for component insertion. (I've omitted several intermediate steps for
brevity.)
Homemade double-sided boards rely on using components' leads as the
vias, but you need to solder the components'
leads on both sides of the board to ensure continuity.
73--
Brad AA1IP