Simply brush a very thin layer of a good tacky flux such as Alpha WS1208 over the pads prior to placement. Even a very thin layer of this flux will be more than enough to allow good wetting to the pads.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Amol Kane (Asteelflash,US)
Sent: Thursday, August 16, 2012 8:34 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

 


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