Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list next in topic

Subject: Re: brass tube vias

From: Paul Alciatore <palciatore@...>
Date: 2017-11-02

You may think that you have a good connection. The top manufacturing company who made the bad boards that I had to repair over and over again certainly did. But you can not trust it. PERIOD. The brass is swagged over the copper trace with a solder coating on it. Both brass and solder alloys are soft metals and expansion/contraction cycles will open a gap large enough for oxygen and other corrosive gasses in the air to penetrate. You will get oxidization and other forms of corrosion and eventually the joint may/will fail. And it will be HELL to find and repair especially with low level, high impedance signals. You could wind up completely replacing a PCB that cost hundreds, thousands, or even tens of thousands of dollars. I have seen it. I have fought it. Brass tubing or hollow brass rivets MUST be soldered for reliability and there is NO way to inspect that solder joint. It will look perfectly normal on the outside while it is was never a proper joint underneath and corrosion sets in. That is, assuming that the brass was not coated with corrosion before it was inserted in the hole.


USE soldered Z wires so you can see and inspect the solder joint if you want a dependable joint. Or get a board made with plated holes.



:

"Dale Chatham 

said,


The one thing one could do with the brass tubing is to make a conical
tool for both sides which will flange the tubing.  Done right, it would
produce an airtight seal and solder would be superfluous (though highly
advised).