Hi, Peter,
I can't help you with how to rework a micro BGA, never having dealt with
them, but I ask a question: Are you wanting to rework them just because
they have voids, or have the voids broken through the side of the balls?
Voids in themselves are not necessarily to be taken as being defects unless
they do break through.
Having had larger BGA's reworked, I can say that changing BGA's is an
expensive pain and better avoided if possible.
My tuppence worth only
Peter Duncan
Peter Lee
<ppwlee@YAHOO To: [log in to unmask]
.COM> cc: (bcc: DUNCAN Peter/Asst Prin Engr/ST
Sent by: Aero/ST Group)
TechNet Subject: Re: [TN] BGA voids
<[log in to unmask]
ORG>
11/20/01
02:29 PM
Please
respond to
"TechNet
E-Mail
Forum."
How would one rework an assembly with micro BGA voiding due to several
micro vias on pad?
Rgds,
Peter
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Brooks,Bill
Sent: November 19, 2001 8:48 AM
To: [log in to unmask]
Subject: Re: [TN] AW: [TN] BGA voids
We used to make PCB's back in the mid 1970's and used a fusing oil
produced by Shell Oil in our Hydro-squeegee. I want to say it was some
sort of Peanut oil... but I can't remember for sure... Those were my
High School years... :)
Good luck... - Bill Brooks
-----Original Message-----
From: David Fish [mailto:[log in to unmask]]
Sent: Monday, November 19, 2001 11:27 AM
To: [log in to unmask]
Subject: Re: [TN] AW: [TN] BGA voids
Who are suppliers of inspection quality oils [Canadian Balson??]
the bear the heat of soldering well?
----- Original Message -----
From: Bob Willis
To: [log in to unmask]
Sent: Monday, November 19, 2001 4:45 AM
Subject: Re: [TN] AW: [TN] BGA voids
The outgassin test for blowhole in printed boards was developed
in the years gone bye after it appeared in and Italian PCB
specification I was asked to review. After some testing I did it
ended up in the IEC specification.
The same oil can be used effectivly for outgassing tests with
via in pad. In the last test I did with ten scrap boards dfrom
different suppliers 2 outgassed on the pads from the vias.
The procedure for through hole which could and has been applied
to vias is on my web site which is in the download section.
Hope this helps.
Bob Willis
Electronic Presentation Services
2 Fourth Ave, Chelmsford, Essex, CM1 4HA England
See us at APEX 2002 www.bobwillis.co.uk/workshops/apex/apex.htm
www.bobwillis.co.uk
Tel: (44) 01245 351502 Fax: (44) 01245 496123
Single solution to your seminar, conference or roadshow
www.seminar-registrations.com
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