On Monday, May 2, 2016 at 8:45:29 AM UTC-4, Phil Allison wrote:
wrote:


** That is a dramatic about face, if I ever saw one.

Please show me where I have _ever_ endorsed, suggested or implied that gold is a useful soldering base for any sort of electronics purposes?

NASA has used gold as a soldering base in space and on the moon due to its tolerance of extreme heat, but they had to go to extraordinary lengths to make it reliable mechanically. Otherwise, not so much. Hence the cost per cubic centimeter of NASA equipment exceeds even that of the US military.

Silver-solder (real tin-free silver solder) is fine for gold, and why it is used for jewelry making. And as I also stated, silver brazing is more accurate as a flame is necessary typically - and in most cases, a flame is not appropriate for electronics.

Further to this, if one looks at what happens to very thin (=1 micron) the gold "leaches" rather than dissolves - and may be easily recovered by any number of methods, not typical of a true solution. The heat breaks the plate bond to the copper substrate and the colloid so formed is very brittle.

http://mysite.du.edu/~jcalvert/phys/copper.htm

gives much more information on the chemistry (or lack thereof) of gold and as it compares to the other "noble" metals.

Peter Wieck
Melrose Park, PA