[R-390] Silver solder

Tue, 25 Jun 2002 07:22:14 -0400

THe solder used by Tektronix was a silver bearing solder.  It contained 2% 
silver.  This can be bought today as 62/36/2 alloy solder.  It is very 
close to Eutectic.  The silver keeps the metalization on the ceramic 
terminal strips from being absorbed by the solder.  The silver bearing 
solder is also required when you do surface mount soldering.  Capacitors 
and resistors have metal deposited on ceramic. The silver is required to 
keep the creamic to metal bond from breaking down.  Ersin makes some very 
good solder.  They used to make (may still do so) a solder called 
sav-a-bit.  This had some copper in the alloy.  Before the days of plated 
soldering iron tips, we had to file to tip to get its shape back after the 
solder induced erosin of the tip. The sav-a-bit solder was to prevent this 
erosion.  There are many alloys of solder and many types of flux.  When 
soldering to a circuit board, I use a water soluable flux.  I never use 
this solder for connectors.  This flus has to be washed from the connection 
a short time after the soldering operation, or it will cause corrosin.  The 
more common rosin flux attracts moisture and becomes sticky trapping dust 
and other particles.  This contaminates the joint and leads to leakage.  A 
very bad problem in high voltage and VHF circuits.

Hope that this helps a little.

73
Glenn

     At 10:34 PM 6/24/02 -0700, Greg Werstiuk wrote:
>It did.
>
>As you may recall, Tektronix used white ceramic terminal blocks for
>component/wiring interconnect.  The solder points on those terminal blocks
>included silver (and possible other metals) to create the bond to the
>ceramic.  The use of "regular" solder could dilute/deplete the silver to the
>point of terminal block failure.
>
>- greg
>
>-----Original Message-----
>From: [email protected] [mailto:[email protected]]On
>Behalf Of [email protected]
>Sent: Monday, June 24, 2002 5:09 PM
>To: [email protected]; [email protected]; [email protected]
>Subject: Re: [R-390] Silver solder
>
>
>Hi fellow solderers,
>
>Dan has me wondering.  The most common solder sold in parts houses when I
>was
>buying same was 60/40 Ersin multicore which worked just fine for most all
>electronic repair and construction use.  On all of our Tektronic equipment,
>however, we were cautioned not to use common electronic solder but the
>solder
>contained on captivated little plastic spools within the equipment.  I don't
>recall now what its composition was but believe it may have had silver
>included.  Does anyone have a better idea about this?
>
>73,
>
>Norm Hall, W6JOD
>
>
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Glenn Little                         [email protected]   QCWA  LM 28417
Amateur Callsign:  WB4UIV            [email protected]   AMSAT LM 2178
QTH:  Goose Creek, SC USA (EM92xx)                      ARRL  TAPR
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