Yes it would. Adding material generally makes thermal conductivity worse. There is no material with negative thermal resistance, so adding more will always increase thermal resistance by at least a bit.
The only exception is 3D geometries, where an increase in surface area due to the extra material can outweigh the effect of the added material, and lead to a net increase in thermal transfer.
This can lead to a paradoxical effect, where ADDING insulation around a pipe leads to HIGHER transfer than with less insulation material, because the added material increases the exterior diameter, and therefore surface area.
(Heatsinks are also a good example. It is more material than just the component by itself, but increases surface area by such a massive amount that it more than outweighs the added material)
This should make the thermal conductivity worse no?
Yes it would. Adding material generally makes thermal conductivity worse. There is no material with negative thermal resistance, so adding more will always increase thermal resistance by at least a bit.
The only exception is 3D geometries, where an increase in surface area due to the extra material can outweigh the effect of the added material, and lead to a net increase in thermal transfer.
This can lead to a paradoxical effect, where ADDING insulation around a pipe leads to HIGHER transfer than with less insulation material, because the added material increases the exterior diameter, and therefore surface area.
(Heatsinks are also a good example. It is more material than just the component by itself, but increases surface area by such a massive amount that it more than outweighs the added material)
Not only that, you add two changes in material on top (copper > glue > pan), which add even more resistance
You are not supposed to out gloves on infants, only mittens, because it makes their hands colder.