Hi Dave,

Just out of curiosity, have you seen the BGA falling or you are just afraid it might?

Because I have ran thousands of BGAs in second reflow (ceramic, metal top, name it), on bottom side, with absolutely no BGA loss. The balls would keep their collapsed aspect, even though they might be slightly stretched, but this is bound to improve compliance, hence long term reliability.

Best regards,

Ioan Tempea
MDA Corporation
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
> Sent: Tuesday, December 09, 2014 8:42 AM
> To: [log in to unmask]
> Subject: [TN] BGA Reflow Issue
>
> Hi gang - looking for an adhesive suggestion. I have an assembly in 
> which a heavy BGA was accidently located on process side one (bottom) 
> so that when we reflow process side two (top) the BGA is doing its 
> best to fall off.
> Unfortunately I can't reverse my process order for a couple of reasons 
> so I am looking for a temporary fix until I can get the assembly 
> revised. I was thinking of using some type of adhesive to temporarily 
> hold the BGA in place during reflow - tack down the corners sort of 
> action. Does anyone have any adhesive (ideally temporary, water 
> washable/removable) suggestions I can investigate?
>
> TIA
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]

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