TECHNET Archives

September 2002

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:
Victor Hernandez <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Tue, 10 Sep 2002 13:51:17 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (142 lines)
Graham,

   Is the " VIBRATION " test within the expected evaluation or do you have a
" MARGINAL " BGA joint, interface, to begin with.   What do cross section of
the failing BGA look like especially the Intermetallic Compound, IMC,
region.   Is this region smooth or evidence of some large nodules at 1000x
after copper etchant application.   Are the failing BGA at random or
location sensitive.   How many REFLOW temperatures did this PCBA received.
BGA are ROBUST interfaces.

victor,

-----Original Message-----
From: Graham Collins [mailto:[log in to unmask]]
Sent: Tuesday, September 10, 2002 11:51 AM
To: [log in to unmask]
Subject: Re: [TN] BGA Under fill


Victor
1) TCE is compatable with the board and bga.  Not sure why that would
influence an answer concerning voids...
2) main purpose is to provide support to solder joints (vibration
resistance).
3) I "hope" to fill the entire gap (100% fill) - but realistically some
voids are likely to occur.  What % of voids are reasonable and acceptable is
the question.
4&5) Loctite 3568 is applied to 2 sides of the component in accordance with
the manufacturer's instructions, the board and part are preheated to 100C
and following application the cure is 15 minutes at 150C.

regards,

Graham Collins
Process Engineer,
Northrop Grumman Canada
Atlantic Facility
(902) 873-2000 ext 6215

>>> [log in to unmask] 09/10/02 10:17AM >>>
Graham,

   Have you considered the thermal properties, TCE, of the Locite 3568
product.
Is this compatible with the TCE of the PCB and device carrier.

   What is the main PURPOSE of the proposed UNDER FILL application?
   How far into the device carrier to you HOPE to FILL?
   Will the LOCITE have to be cured?
   Is the PCB Pre Heated?


Victor,

-----Original Message-----
From: Graham Collins [mailto:[log in to unmask]]
Sent: Tuesday, September 10, 2002 6:09 AM
To: [log in to unmask]
Subject: [TN] BGA Underfill


Good day TechNet!
A question for the BGA / Underfill guru's out there (hopefully we have some
of those online).

Using a capillary flow underfill on a BGA, say a .050 pitch 26x26 array,
what is a reasonable result to expect with respect to voiding?  Should this
process result in no voids, some voids, lots of voids?   Given the size of
this part (1.38" square), is it reasonable to expect a void free underfill?

The particulars: I'm using Loctite 3568 underfill, applied using a syringe
along two edges (L pattern).  Product is on a hotplate at 100C.

Thanks all!

regards

Graham Collins
Process Engineer,
Northrop Grumman
Atlantic Facility of Litton Systems Canada
(902) 873-2000 ext 6215

----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----

----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----

----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------

ATOM RSS1 RSS2