That was easy, just google it:
"
Cryogenics changes the way current flows in a conductor. Aluminum, brass, copper, tin, and lead used in the electron- ics industry are affected by cryogenics. All of these materials exhibit longer wear, and more durability, but they also exhibit a better conductivity rating. When these materials are in the molten state during the metal-making process, as the solidification takes place, some molecules get caught in a random pattern. And we know that molecules do move about at sub- zero and deep cryogenic temperatures, albeit slowly. Liken it if you will to water freezing or crystallizing as it turns to ice. The molecules move to form into a tighter, realigned pattern. Upon returning to room temperature, the molecules stay in this new relationship, producing less random, more even spacing, which in turn reduces the open areas between the grid matrixes to one another. The resulting product exhibits a better electrical current flow. It also strengthens solder to make their joints stronger and less subject to lifting. The printed circuit board material itself loses the stress it has, which helps the board last longer and puts less strain on component parts. The increase in conductivity has been measured between 5% and 10%. This helps cabling, wire, solder runs, and transformers to operate more efficiently."
No