Homebrew PCBs

Not to extend/stray the thread, but just FYI....and
my 2-cent worth below.

Long ago there was a discussion during a coffee break
down at work, where a "QC" guy said he read an article in
NASA Tech Notes.  It was about the reliability
issue of soldered/rivoted thru holes (if I remember
correctly).  The solution (experimentation?) was
to poke a tiny braid thru the hole, cut it off above 
and below then spread out the braid on the pad and solder.
No solder would be "allowed" on the braid down in the
hole...don't know how that could be prevented.
  
The theory was to greatly increase the reliabilty of the
connections, esp during heating/cooling/vibration 
conditions encountered during space flight.

"Plating" thru holes by exploding wires?  Heh...heh...way
over the capabilities of the most dedicated homebrewers, IMHO, 
even if results could ever be close to satisfactory.  But
never stop dreaming up different ways to do things!
 
Charlie
 
On Wed, 2 Jan 2013 20:49:26 -0500 "Boman33" <boman33@...> writes:
  
The problem with the eyelets was that they were tubular rivets. They
solder
on the bottom and filled with solder. Unfortunately it often did not flow
over the top edge to reliably join the top trace.

That is why later rivets were used that had a slit in them and not
tightly
crimped on the top . That way the solder wicked up and spread onto the
top
trace.

Bertho 

From: Bob Macklin Sent: Wednesday, January 02, 2013 19:41
I was an EE for over 40 years. And I remember the brass eyelet problem
well.

But I think trying to simulate plated through holes on home made PCB is
going way too far.

I have been using wirewrap wire to fake the vias. I know you cannot put
them
under components.

On real PCBs the plated though holds are made on each layer before
etching.
Then the boards are sandwiched together.

This is just too much to try on homemade PCBs.

The sensitizing solution can be purchased and you can make real plated
through holes if you really need them.

But that's too much trouble for me. I only use the TT process to make
small
quantities of boards for ham radio projects.

Bob Macklin

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