Solder Conductiivity compare to Copper

Discussion in 'General Electronics Chat' started by Management, Aug 18, 2009.

  1. Management

    Thread Starter Active Member

    Sep 18, 2007
    Does anyone know what the % difference in conductivity be between high lead solder and copper? I saw somewhere that high lead solder was like 8% the conductivity of copper.

    Is that true or do you know another percentage?

    Thank you.
  2. beenthere

    Retired Moderator

    Apr 20, 2004
  3. KL7AJ

    Senior Member

    Nov 4, 2008
    Those numbers are about right for a hunk of solder "in the wild." However, a properly soldered CONNECTION can be MUCH MUCH better than that. This is because CORRECT soldering actually forms a new copper based alloy on the surface of the base metals....nearly as good as copper itself. This is NOT true of a bad "cold" solder connection, however, where the conductivity can actually be much WORSE than raw solder.

  4. rspuzio

    Active Member

    Jan 19, 2009
    According to the CRC Handbook:

    Cu: 1.7 μΩ cm
    50% Pb - 50% Sn: 15 μΩ cm
    Pb: 19.2 μΩ cm

    Perhaps not exactly the alloy you had in mind (50-50 as opposed
    to 60-40), but the figure of 8% looks about right. maybe a bit low -
    -- for the 50-50 alloy, we have 8.8%, for pure lead 11.3%.

    I guess that explains why we use copper in long, thin wires
    but only make thick blobs out of the solder.
  5. peranders

    Well-Known Member

    May 21, 2007