Typical DI wash water is not all that pure and generally the hotter the
water the better, normally below 140°F however, because higher water temps
damage the DI resin bed (presume mixed bed).

RMA flux processed witth high reflow temps can create difficult non-ionic
residues that are white. And this is a high temp alloy. I wonder if the flux
chemistry is causing your problem.
  -----Original Message-----
  From: TechNet [mailto:[log in to unmask]]On Behalf Of Charlie Pitarys
  Sent: Wednesday, May 01, 2002 11:52 AM
  To: [log in to unmask]
  Subject: [TN] High lead composition solder paste and rinse water.


  Hello,
  I have a customer using a 95Pb/5Sn/2.5ag composition solder paste in a
high temp copper lead frame application. The RMA flux is being cleaned but
white residue around the solder points is noticed after the multiple rinse
stages and dry (ultrasonic batch process).
  Suspicion of having the rinse water too hot combined with the effects of
high purity DI water causing corrosion to the lead solder.  Should the dryer
be inerted?  Am I off base here?

  Looking for advice from others using this type of solder formula .

  Thanks
  Charlie Pitarys
  Director of Application Technologies
  603.622.2900 X-115
  www.kyzen.com