Solder is NEVER suitable as a mechanical joint.
Peter
If the joint isnt going to get too hot (expand/contract with
temperature causing metal fatigue and cracking of the joint, or
overheat to the point that the solder starts to melt and form a dry
joint), or suffers lots of vibration that puts mechanical stress on
the join, and is done properly, on clean surfaces with enough solder
and the right soldering temperature it won't give any problems.
In consumer electronics pretty much all components, connectors, wires
etc are all held in their PCB's by solder alone. SMD devices are
usually glued down before soldering, but this is more to keep them in
place when they go through wave soldering, (board is turned upside
down during this process) the glue is not necessary to keep them there
once soldered in. (note - wires that go to plugs and headers are
typically crimped or use IDC to hold in place).
What is done in applications like military and space equipment, I dont
know.
I think you are thinking back to the old days with valve equipment
where there was a belief that joints (component leads and connecting
wires were attached to tag strips) should make adequate electrical
connection without needing solder (by being wrapped around the
terminal, or later, wire wrap,) and the solder should only be applied
to cover, protect and seal the join, not to make the electrical
connection.
If you have ever tried to unsolder and remove a component from one of
these chassis, you will know what I'm talking about
