What type of paste are you using? We are processing a bga 1x.8 with a .5 pitch and .175 ball diameter. We are using a Kester lead free EM828 solder paste. We have the stencil
Apertures cut square encompassing the round pad. This allows for slightly more paste.
Hope this helps,
Brien

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Amol Kane (Asteelflash,US)
Sent: Thursday, August 16, 2012 9:34 AM
To: [log in to unmask]
Subject: [TN] CSP BGAs

Dear Technetters,

We are going to be assembling some lead-free  1.6x0.8 mm micro BGAs with 0.5mm pitch and 0.17mm dia board pads. Anybody else have experience with this small a package?....I am concerned that there won't be sufficient flux in the tiny solder deposit to clean the oxides during reflow, leading to graping and/or head in pillow situation. Do I need a dip fluxer for the part to do a flux only attachment, or to augment the amount of flux in the solderpaste-solder bump system? I am told I have no time to do DOEs to determine stencil and reflow parameters, so I am turning to technet for help.....any thoughts?





Regards,

Amol




______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________

WARNING: Export Control
This message, including any attachments, may contain technical data within the definition of the International Traffic in Arms Regulations (ITAR), and subject to the Export Control Laws of the U.S. Government. Transfer of such information by any means to a foreign person, whether in the United States or abroad, without proper export authorization or other approval from the U.S. Department of State is prohibited.

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________