TECHNET Archives

April 1999

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
"Carano,Michael" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Thu, 1 Apr 1999 15:11:26 +0100
Content-Type:
text/plain
Parts/Attachments:
text/plain (76 lines)
It is true that sulfamate nickel inherently has less stress than sulfate
nickel. The main reason is that sulfate nickel plating chemistry contains
nickel chloride. The chloride itself has been proven to cause more stress in
the deposit. You may also want to make sure that any organic additions
agents used in the process do not contribute any significant amounts of
stress. If sulfate nickel is employed, use an additive that only imparts a
semi-bright finish to the nickel, such as the sodium saccharin type
additives.
        -----Original Message-----
        From:   Au Po Lam, Benny [SMTP:[log in to unmask]]
        Sent:   Wednesday, March 31, 1999 8:24 PM
        To:     [log in to unmask]
        Subject:        [TN] Ni Plating for wire bond

        Hello Everyone,

        What kind of chemistry do you recommend for electrolytic Ni plate,
sulfamate
        or sulfate nickel, as applied on thermosonic wire-bond PCB? I was
told long
        time ago that sulfamate nickel is a 'low-stress' nickel being used
in
        various metal finishing jobs, including PCB; while the latter comes
from a
        Watt nickel bath. Some BGA designers says that as long as the metal
surface
        is clean, the two nickel types should work equally well.

        I recently tried both and found that the sulfate nickel has a better
        bondability, despite the fact that they come from two different
vendors.

        Can anyone tell me about the surface topography of each type of
nickel? Do
        they have different atomic packing in the plated layer? What
actually does
        low/high -stress mean, something related to hardness? Assuming they
have the
        same amount of gold plated on top, which one is more suitable for
gold wire
        ball bond?

        Thanks in advance!

        Regards, Benny.

        Wire Bonder Process Eng'g
        ASM Assembly Automation

        ################################################################
        TechNet E-Mail Forum provided as a free service by IPC using
LISTSERV 1.8c
        ################################################################
        To subscribe/unsubscribe, send a message to [log in to unmask] with
following text in the body:
        To subscribe:   SUBSCRIBE TechNet <your full name>
        To unsubscribe:   SIGNOFF TechNet
        ################################################################
        Please visit IPC's web site (http://www.ipc.org) "On-Line Services"
section for additional information.
        For technical support contact Hugo Scaramuzza at [log in to unmask] or
847-509-9700 ext.312
        ################################################################

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################


ATOM RSS1 RSS2