Dear Joe,
3M company has Z-conductive anisotropix tape that can be used for
temporarily use to test components.
Peer Langeveld
Consultant Soft Soldering Processes
5502 VH 8 NL
2006/7/20, Stadem, Richard D. <[log in to unmask]>:
> Joe,
> I did not see your note about test sockets not being an option. So here
> is another method of temporary attachment.
> If the pwb has holes in it for heatsink clamping onto the BGA, use them
> to clamp a small aluminum bar across the top of the BGA. The process
> goes like this:
> 1. Start with a clean dry circuit board. Place the BGA
> ball-side-down on a small flat piece of tool steel and gently rub
> back and forth while applying a light pressure. This will create a
> flat spot on the bottom of the solder balls. When each solder ball
> has a small flat spot you know they will all make contact with the
> pwb pads later.
> 2. Apply a very, very light coat of tacky flux to the pads to
> help hold the BGA in place. Do not get the flux outside of the BGA
> body perimeter.
> 3. Place the board into your rework machine, pick it up with the
> vacuum, and align the BGA to the pads and place it as if you were
> going to do a rework. Use a nozzle much smaller than the component
> body.
> 4.Place the part onto its pads, but leave the nozzle down on the
> part. Using ESD- safe masking tape, tape the four sides of the
> BGA down but leave the holes in the PWB clear.
> 5. Lift the nozzle. Remove the board. Place the aluminum bar on
> the top of the BGA and gently tighten the screws/nuts to clamp the
> BGA to the pads.
> 6. X-ray to verify the alignment. Check the polarity as well.
> 7. Gently wash the board to remove the flux.
> 8. Power up and see the cool blue sparks/corona/smoke under the
> BGA (just kidding).
>
> If the pwb does not have any mounting holes, epoxy two pemnuts to the
> pwb on each side of the BGA pattern to use as screw retainers. Use SMT
> epoxy, it can be gently chipped off after you are finished. You can heat
> it up slightly for easier removal without any harm to the pwb.
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Macko, Joe @ IEC
> Sent: Thursday, July 20, 2006 12:16 PM
> To: [log in to unmask]
> Subject: [TN] temporary attachment of a BGA to a PCB for test
>
> Fellow techs,
>
>
>
> I have been asked to determine if there is a way to temporarily install
> a BGA onto a test board using some type of conductive adhesive to make
> electrical contact, electrical test and then safely remove the adhesive
> without damaging the solder balls and be able to use the BGA.
>
>
>
> Sounds impossible but I informed the design group I would check out the
> options.
>
>
>
> The other option we are looking at is to design a clamp/pallet that will
> securely hold the BGA to the board. The problem here may be making 100%
> electrical contact on all 48 balls.
>
>
>
> Anyone have any creative ideas they would like to share? Test sockets
> are not an option.
>
>
>
>
>
> thanks
>
> Joe
>
>
>
>
>
>
> ---------------------------------------------------
> Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for
> additional information, or contact Keach Sasamori at [log in to unmask] or
> 847-615-7100 ext.2815
> -----------------------------------------------------
>
> ---------------------------------------------------
> Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
> -----------------------------------------------------
>
---------------------------------------------------
Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
|
