TECHNET Archives

July 2009

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:
Vladimir Igoshev <[log in to unmask]>
Reply To:
Date:
Fri, 10 Jul 2009 12:15:15 +0000
Content-Type:
text/plain
Parts/Attachments:
text/plain (1 lines)
Bev, no one would be able to tell what the temperature was (in normal operation it's not supposed to go higher than 100-110 C, if I'm not mistaken).


In some of them it was definitely a case of thermal run away (as the intermetallic could be 15 - 20 micron thick!!!!), while others look normal. Time-wise: from months up to 2-3 years (due to the length of product warranty).

Vladimir
SENTEC
SENTEC
11 Canadian Road, Unit 7.
Scarborough, ON M1R 5G1
Tel: (416) 899-1882
Fax: (905) 882-8812
www.sentec.ca


-----Original Message-----
From: Bev Christian <[log in to unmask]>

Date: Fri, 10 Jul 2009 08:08:08
To: <[log in to unmask]>
Subject: Re: [TN] More Underfill Discussion


How long in the field and what temperature was the part running at?
Bev

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev
Sent: Friday, July 10, 2009 8:07 AM
To: [log in to unmask]
Subject: Re: [TN] More Underfill Discussion

It's kind of a known problem ("solder extrusion") and I've seen quite a
bit of it in graphic ASICs from field return (not even TC tests).

Regards,

Vladimir
SENTEC
SENTEC
11 Canadian Road, Unit 7.
Scarborough, ON M1R 5G1
Tel: (416) 899-1882
Fax: (905) 882-8812
www.sentec.ca


-----Original Message-----
From: "Post, Scott E" <[log in to unmask]>

Date: Fri, 10 Jul 2009 07:40:17
To: <[log in to unmask]>
Subject: Re: [TN] More Underfill Discussion



One problem I've seen with underfill voids between flipchip bumps (8-10
mil pitch) is solder extrusion into the void during thermal cycling.
I've seen the extrusion go far enough to cause shorts. This was in
-40/+150C cycling, so quite a bit harsher than most situations. Also,
it was SnPb solder. I don't know if a SAC alloy would extrude so
readily. As far as how long it took, I can't say for sure. My tests
typically ran 3000 cycles and I found the extrusions in cross-sections
at the end of testing. My monitoring equipment wasn't accurate enough
to pick up a partial short like this and, to be honest, I was looking
for increases in resistance, not decreases.

Scott Post
P.O.U. 1415-00M2-00P6
2151 E. Lincoln Road
Kokomo, Indiana 46904-9005
765-451-2983 (Phone)
765-451-0287 (FAX)

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Bev Christian
Sent: Thursday, July 09, 2009 4:10 PM
To: [log in to unmask]
Subject: [TN] More Underfill Discussion

TechNetters,
Well I have been shopping to Class 2 people the draft we all built here
on TechNet of a standard for underfill workmanship. Some are saying
they can't live with voids that only go 50% around the perimeter of a
solder ball, they want more leeway. They also say they want to allow
voids connecting solder balls. Now I put in the prohibition of the
latter because of the statement in the J-STD-030 "Guideline for
Selection and Application of Underfill Material for Flip Chip and Other
Micropackages", where it talks about unequal stresses put on the solder
balls when they is not 100 underfill coverage around each and every
ball. My questions to you are:
1) What is the physical evidence behind that statement in 030?
2) What was the magnitude of the deformation?
3) How long did it take?

My reason for the last question is if it takes 9 years for significant,
reliability impairing deformation to occur in a 20 year life product,
that is real bad. But if it happens in the products with a 2 to 3 year
life product, why should we care?

Bev
RIM


---------------------------------------------------------------------
This transmission (including any attachments) may contain confidential
information, privileged material (including material protected by the
solicitor-client or other applicable privileges), or constitute
non-public information. Any use of this information by anyone other than
the intended recipient is prohibited. If you have received this
transmission in error, please immediately reply to the sender and delete
this information from your system. Use, dissemination, distribution, or
reproduction of this transmission by unintended recipients is not
authorized and may be unlawful.

---------------------------------------------------
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
-----------------------------------------------------

************************************************************************
****************
Note: If the reader of this message is not the intended recipient, or
an employee or agent responsible for delivering this message to the
intended recipient, you are hereby notified that any dissemination,
distribution or copying of this communication is strictly prohibited. If
you have received this communication in error, please notify us
immediately by replying to the message and deleting it from your
computer. Thank you.
************************************************************************
****************

************************************************************************
****************
Note: If the reader of this message is not the intended recipient, or
an employee or agent responsible for delivering this message to the
intended recipient, you are hereby notified that any dissemination,
distribution or copying of this communication is strictly prohibited. If
you have received this communication in error, please notify us
immediately by replying to the message and deleting it from your
computer. Thank you.
************************************************************************
****************

---------------------------------------------------
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 transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.

---------------------------------------------------
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