With flux alone, you lose the additional solder volume that the paste gives you (reducing the standoff). However, using tacky flux to attach BGAs has shown to significantly reduce voiding when compared to paste.

If your assembly has both PBGA and other components, it likely doesn't make much sense to use flux, since the other components will need paste.

Regards,

Tim Jensen

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Guy Ramsey
Sent: Friday, September 07, 2001 1:26 PM
To: [log in to unmask]
Subject: [TN] Paste verses tacky flux

Anyone out there with data, case study, anecdotal evidence, strong opinions, relative to installation of PBGA components (with eutectic solder balls of course) using micro stencil and solder paste verses tacky flux.

Guy Ramsey
Senior Lab Technician / Instructor

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