>I get a bunch of nice spherical silver solder balls sitting in a
>field of dried out grey mud
Copper mass is such that there is insufficient heat to raise
copper/paste temperature to proper range in a reasonable timeframe.
Instead, the flux dries out well ahead of solder melting and starts to
do more harm than good. If this is a test using an unetched piece of
board then it may never work in that oven.
You could try bringing the oven to maximum temperature for a while
before placing the pasted board inside but even that may not work if
there is too much copper. I use a hot air gun most of the time and an
oven when there isn't too much copper to tin.
--- In
Homebrew_PCBs@yahoogroups.com, "Mark Merclean" <mamhouse@...>
wrote:
>