Hello Richard,
So you are talking flux only attachment?......I carefully added flux
with a manual dispenser and a fine gauge syringe after printing and
placement on some test vehicles and the BGA did solder (brushing flux
BEFORE printing does not help as the paste deposit does not stick to the
pads). However we will be building hundreds of these assemblies and I
need a repeatable process. There was flux voiding based on the amount of
flux each part got. 

I just wanted to validate my hypothesis about the HIP and graping on
such tiny components and see if anybody was already using dip fluxers
for such components

Thanks!
Amol


-----Original Message-----
From: Stadem, Richard D. [mailto:[log in to unmask]] 
Sent: Thursday, August 16, 2012 9:51 AM
To: TechNet E-Mail Forum; Amol Kane (Asteelflash,US)
Subject: RE: CSP BGAs

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

 


______________________________________________________________________
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]
______________________________________________________________________

______________________________________________________________________
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] 
______________________________________________________________________