The numbers you yourself reported show that copper is much more thermally conductive than solder, and not the other way around.
Thermal conductivity describes how quickly the heat conducts through the wire. Since the wire is uniformly heated, this is a minor detail (assuming that the wire's thermal conductivity is considerably higher than the electrical insulation around the wire). Instead, you need to look for the heat transfer coefficient of insulated wire.
The melting point of Sn63Pb37 is 183C, not 140C. 183 is not "around 140."
If the wire were hot enough to melt the solder in a copper+solder combination then it would be well more than hot enough to melt the plastic insulation around just the copper wire itself, which is typically rated for only 90C.
The numbers you yourself reported show that copper is much more thermally conductive than solder, and not the other way around.
Thermal conductivity describes how quickly the heat conducts through the wire. Since the wire is uniformly heated, this is a minor detail (assuming that the wire's thermal conductivity is considerably higher than the electrical insulation around the wire). Instead, you need to look for the heat transfer coefficient of insulated wire.
The melting point of Sn63Pb37 is 183C, not 140C. 183 is not "around 140."
If the wire were hot enough to melt the solder in a copper+solder combination then it would be well more than hot enough to melt the plastic insulation around just the copper wire itself, which is typically rated for only 90C.