TECHNET Archives

November 2010

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:
Steven Creswick <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Steven Creswick <[log in to unmask]>
Date:
Sat, 13 Nov 2010 08:32:53 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (121 lines)
Mumtaz,

You have gotten good responses thus far.

My assumption is, this is 'normal' forward bonding.  If 'reverse' bonding,
invert my comments on first/second - front/back radius.

We are zeroed in on the Al/Al bond.

I particularly echo Wayne's comments on looping and tail.  Aluminum wedge
bonding is particularly sensitive to details - definitely much less
forgiving than gold ball bonding, for example.  Absolutely!  Be very careful
when working on the loop formation.

I suggest that rather than looking at the remnants of the pulled bonds, you
first look at the intact bonds - paying particular attention to any looping
differences and especially to the region of the first bond heel.  In the
program, look for differences in looping parameters, and if that corresponds
to pre and post wire pull differences.

You may find that your 'strongest' wires are the longest ones, etc.  Look
for those telltale cracks in the first bond heel and develop a 'feel' for
the impact of the crack magnitude on resultant pull strength - and what your
organization deems to be acceptable.  Note - Most times, one can find what
appear to be 'cracks' in ANY first bond heel, if one cranks up the
magnification enough...

I would also contemplate increasing the back radius of the tool subject to
what you can/can not do with respect to looping.

You indicate that the pulls are 'post seal'.  What time/temp regime have
they been subjected to?  Since a little bit of heat can facilitate a large
amount of stress relief, make sure your time/temp exposures are consistent.


Steve Creswick
http://www.linkedin.com/in/stevencreswick







-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Mumtaz Bora
Sent: Friday, November 12, 2010 9:15 PM
To: [log in to unmask]
Subject: [TN] Wire Bond Pull failures

Hello TechNetters,
 
I have some wirebonds on a Hi -Rel package that pulled below 2.0 gm
minimum  per Mil -Std -883. I have taken some SEM images of failed and
good bonds. Customer has a concern with plane of fracture of the failed
bonds even though it is break at "neck" . . It is Aluminum wire/to
Aluminum bond pad wedge bonded ultrasonically and aluminum wire to gold
plated post also bonded ultrasonic. Wire pull is post seal. I have
uploaded the file of images on the TechNet groupsite .I will appreciate
some feedback from wirebonding experts on the forum.
 
 http://ipc-technet.groupsite.com/main/summary
<http://ipc-technet.groupsite.com/main/summary> 

Thank-you, Mumtaz

Mumtaz Bora

Senior Packaging Engineer

Peregrine Semiconductor

9380 Carroll Park Drive

San Diego, CA 92121

858-795-0112-direct

858-731-9499 -fax

[log in to unmask]

 

 

______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------


______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------

ATOM RSS1 RSS2