Dave:

We use Chemask (no financial interest!), tacking down the corners and cure.
Run the process (reflow temp) then clean it off.

Bob Wettermann/BEST

On Tue, Dec 9, 2014 at 8:09 AM, Wayne Thayer <[log in to unmask]> wrote:

> Seems like perfect use for a staking adhesive, except for your strange
> requirement that it be easily removable. Staking adhesives enhance
> reliability
> by assisting with strengthening the mechanics at the corner balls, and are
> known to increase the resistance to shock loads too.
>
> So if you're stuck with this strange set of requirements, then I doubt
> you'll
> find something pre-qualified for it. So since qualification is required,
> anything is open game. I'd play with water washable solder masking
> materials,
> also peelable masking material.
>
> Wayne Thayer
>
> -----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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-- 
Bob Wettermann
BEST Inc
[log in to unmask]
Cell: 847-767-5745


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