TECHNET Archives

November 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:
Ghassan Abu-Hamdeh <[log in to unmask]>
Reply To:
Date:
Wed, 3 Nov 1999 08:09:59 PST
Content-Type:
text/plain
Parts/Attachments:
text/plain (105 lines)
You can mask it yourself using a peelable solder mask.

<[log in to unmask]> Wrote:
|
| Date:    Tue, 2 Nov 1999 19:17:59 -0500
| From:    jong s kadesch <[log in to unmask]>
| Subject: CGA attachment on BGA pattern
|
| Dear TechNetters,
|
| I have a substrate with BGA pattern where BGA is fanned
| out for vias.
| Dimensions are following:
|
| Diameter of the ball: 30 mil
| Pitch: 50 mil
| via drill size: 6 mil
| via with annular ring: 10 mil
|
| The substrate is solder masked for CGA attachment but
| exposing all the vias
| (no solder mask on vias) and of course, BGA pattern.  CGA
| attachment cannot
| be done because one BGA pad is too close to the via fanned
| out from another
| BGA pad (average distance between two is 5 mil) which will
| cause short in
| the event of solder bridge between the BGA pad and the via
| during eutectic
| solder reflow process.
|
| Is there any way that i can fix this problem without
| sending these
| substrates back to manufacturer for remasking?
| Thanks in advance.
|
|
| Jong Kadesch
| ***************************************
|
| Jong,
|
| You might try "reballing" the devices using "hi-temp"
| spheres (Sn90 Pb10) utilizing eutectic
| solder paste underprinted by 20%. This will minimize the
| probability of encroaching liquidus
| material during reflow. If you have interest in persuing
| this process on a "test" basis, please
| feel free to contact me directly.
|
| Regards,
|
| Ed Popielarski
|
| QTA Machine
| 10 McLaren, Ste. D
| Irvine, Ca. 92618
|
| 949-581-6601 Ph
| 949-581-2448 Fx
| http://www.qta.net
| Ask about our BGA Reballing system!
|
| ##########################################################
| ####
| TechNet Mail List 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 web site
| (http://www.ipc.org/html/forum.htm) for additional
| information.
| If you need assistance - contact Gayatri Sardeshpande at
| [log in to unmask] or
| 847-509-9700 ext.5365
| ##########################################################
| ####
|


Gus Abu-Hamdeh
Maxtek Components Corporation
(503)627-2392

##############################################################
TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################

ATOM RSS1 RSS2