As I know ENIG in plated through hole come from electroless copper
plating. In Electroless copper process it has one step that we call
activator normally will contain Palladium. Sometime after electroless
it still remain some palladium in hole. So when they come through ENIG ,
as you know  this process also used palladium before plated Nickel. What
happen is everywhere that has palladium nickel will plated and then
Gold.




Somtawin Pornpottanamas
Material Engineer
Kimball Electronics (Thailand)
Tel. 038-401566  ext. 211
Fax. 038-495029

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of d. terstegge
Sent: Thursday, February 05, 2004 10:13 PM
To: [log in to unmask]
Subject: [TN] Goldresidues in non-plated holes

Hi Technet,

I looked at an ENIG board today and noticed it had some gold-residues
in the nonplated holes.
I always thought that a non-plated hole should not have any plating at
all, but seeing this condition for the second time (the first time was
on a board from another manufacturer and another designer) I almost
begin to think this is a normal condition.
What do you think, is this normal, is it acceptable (I don't think so),
any idea what causes it ? For those who like to see a photograph of
this, see: http://www.smtinfo.net/forum/index.php?showtopic=40

Daan Terstegge
Thales Communications
Unclassified mail
Personal Website: http://www.smtinfo.net

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