TECHNET Archives

May 1998

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:
Jeremy POLLARD <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Fri, 29 May 1998 14:30:34 +0930
Content-Type:
text/plain
Parts/Attachments:
text/plain (30 lines)
Hello,
am hoping that someone out there has experience with BGA footprints.

We have completed Rev 1 of a double Eurocard PCB, 10 Layers with 7 x 356 pin BGA devices on board. While everything went well with this run and we had no problems with ball connections, it is impossible to perform any rework or modifications if required.
The footprint was the recommended pad with track out to a via or  " Dog bone". On the next revision we would like to do the following, Elimnate the "dogbone", place a through hole in the actual pad for the ball and adjust the solder paste stencil so that the volume of paste deposited allows for the hole through the board.
I would use a hole size of 0.3mm (12mil) to 0.4mm(16mil) certainly no larger.
This approach should enable us to rework dodgy joints from the solder side of the PCB
It will also allow us access possibly to test the pins from the BGA.

Has anyone done this ?
Was it succesfull in a production environment ?

Many thanks foryour help.

regards

jeremy

################################################################
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 web site (http://jefry.ipc.org/forum.htm) for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################


ATOM RSS1 RSS2