[Elecraft] Re: Elecraft digest, Vol 4 #487 - 64 msgs

Thu Mar 25 10:43:00 2004

Hi

Although I agree with most of this post I have to disagree with this. =
Yes 63/37 eutectic solder "sets up quicker" It goes from a liquid to a =
solid at one temperature and this is the lowest temperature of any alloy =
combination of tin/lead. At any other combination of tin/lead the solder =
goes through a semi solid plastic state. In this state the solder will =
not flow but if the component is moved the joint will crystallize and in =
many cases form a poor electrical connection as well as a poor =
mechanical connection. This may not show up for months or years later.=20

Because the melting point is lower a component that is under rework is =
actually easer to remove or touch up. The joint will stay molten longer =
and the instant change to solid will help prevent damage to the plated =
through holes by trying to pull the component lead out while the solder =
in in the plastic state.=20

The bottom line is, you can build with 60/40 solder but it will be =
easier to build AND rework with 63/37 eutectic solder. This is why it is =
specified for Military and NASA electronic work.

Don Brown
KD5NDB

  ----- Original Message -----=20
  From: [email protected]<mailto:[email protected]>=20
  To: [email protected]<mailto:[email protected]>=20
  Sent: Thursday, March 25, 2004 9:18 AM
  Subject: [Elecraft] Re: Elecraft digest, Vol 4 #487 - 64 msgs

  Snip

  ...As for the 63/37 eutectic
  solder, building is not a problem with it...Rework is, because it sets =
up
  so quickly, before all the solder is removed, Jerry, wa2dkg
  K2 #2549

  Snip

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